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METAL AND METALLOID PARTICULATES
IN WORKPLACE ATMOSPHERES (ICP ANALYSIS)


Method no.: ID-125G
    
Control no.: T-ID125G-FV-03-0209-M
    
Matrix: Air, Wipe, or Bulk
   
OSHA Permissible Exposure Limits: Permissible Exposure Limits (PELs) are listed in Table 1 for elements commonly found in industrial environments. This method has the capability of sampling and analyzing more than these elements, the number being limited by instrumental capability, as well as digestion solubility and stability.
   
Collection Procedure: A calibrated personal sampling pump is used to draw a known volume of air through a mixed-cellulose ester membrane filter contained in a styrene cassette.
   
Minimum Recommended Air Volumes: Time Weighted Average Samples - 480 L
Short-Term Exposure Limit Samples - 30 L*
Ceiling Samples - 30 L
   
Recommended Sampling Rate: 2 L/min 
   
Analytical Procedure: Filters are digested with nitric acid, sulfuric acid and hydrogen peroxide. Dissolution of the elements is facilitated by addition of hydrochloric acid. Analysis is performed using Inductively Coupled Argon Plasma-Atomic Emission Spectroscopy (ICAP-AES).
   
Detection Limits: See Table 2
   
Validation Level: See Table 3
   
Precision and Accuracy: See Table 3
   
Method Classification: Validated analytical method
   
Chemist: Jerry Septon, Ray Abel, Michael Simmons
   
Date (Revised): November, 1988 (September, 2002)
   
*   Take 60-L samples when evaluating STEL exposures to beryllium.
   
Commercial manufacturers and products mentioned in this method are for descriptive use only and do not constitute endorsements by USDOL-OSHA. Similar products from other sources can be substituted.
   
Division of Physical Measurements and Inorganic Analyses
OSHA Technical Center
Sandy City, Utah
 
1. Introduction
1.1 Scope
1.1.1 This method describes the collection and subsequent analysis of airborne metal and metalloid particulate by Inductively Coupled Argon Plasma-Atomic Emission Spectroscopy (ICAP-AES).

1.1.2 This method provides rapid simultaneous analysis and data reduction for a wide range of elements, eliminating the necessity of separate analyses by conventional atomic absorption techniques.

1.1.3 This method was validated for 13 elements (Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, V, and Zn).  Other elements can be added to or subtracted from the method. The capability for expanding the analysis to other elements is mainly dependent on laboratory instrumentation and element solubility and stability in the acid matrix used for digestion.
1.2 History
1.2.1.Previous to the introduction of ICAP-AES, samples containing metallic particulates were digested in a variety of ways and analyzed by Atomic Absorption Spectroscopy (AAS) at the OSHA Analytical Laboratory.

1.2.2 A first generation plasma source and spectrometer (Jarrell-Ash Model 975 Atomcomp) was then used by the OSHA Analytical Laboratory. The analytical procedure for this instrument is described in OSHA Method No. ID-125 (8.1).

1.2.3 Procurement of new inductively coupled plasma (ICP) instruments, computers, and software allowed samples to be determined using later technology. This technology includes more sophisticated computer systems for data reduction and instrument control.

1.2.4 When this method was originally written, three different ICP instruments at the OSHA Salt Lake Technical Center (OSHA-SLTC) are used to apply this method:
Jobin-Yvon (JY) Model 32 (Instruments SA, Edison, NJ)
Jarrell-Ash Model 975 Atomcomp* (Thermo Jarrell-Ash Corp., Franklin, MA)
Applied Research Lab. (ARL) Model 3560 (ARL, Sunland, CA)
These instruments are further referred to as ICP1, ICP2, or ICP3, respectively.

The Jarrell-Ash system was upgraded with a new computer, generator, and software in 1989.

This method is applicable to any simultaneous spectrometer. This method was validated using ICP1 and the data is presented in a backup report (8.2). An additional evaluation was performed using ICP3 (8.3).
2. Detection Limits and Working Ranges (8.2)
2.1 OSHA Permissible Exposure Limits (PELs) (8.4) for the elements screened and validated are listed in Table 1. Detection limits and working ranges are in Table 2. All reported detection limits were calculated for 50-mL solution volumes.

2.2 The optimum working range for each element listed in Table 2 extends several orders of magnitude above each detection limit.
3. Method Performance (8.2)
3.1 The precision and accuracy data for the 13 validated elements using ICP1 are listed in Table 3. These values are based on six samples at each concentration level tested. Solutions of the 13 elements were spiked on mixed-cellulose ester filters. These samples were then digested and analyzed using procedures mentioned in this method and in reference 8.2.

3.2 Nine of the thirteen elements reported in Table 3 were spiked at 0.5, 1, and 2 times the PEL, assuming a 120-L air volume. Spikes for manganese were calculated assuming a 30-L air volume. Approximately 200-L air volumes were assumed for Pb, Ni, and Sb.

3.3 The analytical error (AE) at 95% confidence for each element listed in Table 3 was calculated as:

±AE% = 100 × [|Mean Bias| + 2(CV)]

Analytical errors for all elements tested were within ±25%; the greatest value was ±18.1% for V. This element was validated near it's detection limit.
4. Interferences (8.6)
 
High temperatures present in the plasma (5,000 to 8,000°C) minimize most chemical and matrix interferences. Interferences do exist, however, and can be categorized as follows:
4.1 Physical interferences such as nebulization and transport effects are influences that determine the rate and particle size in which analytes are delivered to the plasma. These effects are minimized by matching the acid concentrations of samples and standards.

4.2 Chemical interferences are characterized by molecular compound formation, ionization effects, and solute volatilization effects. These effects are not severe in ICP analysis and are minimized by matrix matching and careful selection of operating conditions such as: incident plasma source power, sample uptake rate and plasma observation height.

4.3 Spectral interferences include:
  1. Unresolved overlap of molecular band spectra.
  2. Overlap of a spectral line from another element.
  3. Background from continuous or recombination phenomena.
  4. Background from stray light.
4.4 The first effect (a) can be minimized by a careful selection of wavelengths for the reported elements. The other types of spectral interferences (spectral overlap and elevated background) are minimized by software which performs interelement corrections. This software assumes a linear relationship between the analyte and interference within the working range limits. A spectral interference correction equation typically used by ICP manufacturers is:

Corrected Concn = Calculated Concn - Ai × CPi

where:
Ai is Correction factor
CPi is Concentration of the interfering element

Samples having analyte concentrations above the working range limits should be diluted into range; interelement corrections may not be accurate above the working range. Experimentally determined interelement corrections for the validated elements are listed in reference 8.2.

4.5. If necessary, supplemental background correction can be performed with additional software supplied by the instrument manufacturer.
5. Sampling
5.1 Equipment
5.1.1 Mixed cellulose ester (MCE) filters (0.8-µm pore size), cellulose backup pads, and cassettes, 37-mm diameter, part no. MAWP 037 AO (Millipore Corp., Bedford, MA). Cassettes, filters (MCE) and backup pads of 25-mm diameter can also be used.

5.1.2 Gel bands (Omega Specialty Instrument Co., Chelmsford, MA) for sealing cassettes.

5.1.3 Sampling pumps capable of sampling at 2 L/min.

5.1.4 Assorted flexible tubing.

5.1.5 Stopwatch and bubble tube or meter for pump calibration.

5.1.6 Scintillation vials, 20-mL, part no. 74515 or 58515, (Kimble, Div. of Owens-Illinois Inc., Toledo, OH) with polypropylene or Teflon cap liners. If possible, submit bulk or wipe samples in these vials for ICP analysis.

5.1.7 Smear tabs, part no. 225-24 (SKC Inc., Eighty Four, PA), or Whatman no. 41 or no. 42 filters (Whatman LabSales Inc. , Hillsboro, OR) for wipe sampling.

5.1.8 Gloves, disposable (for wipe sampling).

5.1.9 Ghost Wipes, 4" × 4" 1000/cs Wet with DI Water, part no. SC4250 (Environmental Express, Mt. Pleasant, SC) for wipe sampling.
5.2 Sampling Procedure - Air Samples

Welding fumes and samples requiring sample weights can be characterized using this method. Collect samples on pre-weighed 37-mm polyvinyl chloride (PVC) filters at 2 L/min flow rate. Conduct the welding fume sampling with the filter cassette located inside the welding helmet (8.6). If the free-space inside the hood precludes the use of 37-mm diameter cassettes and filters, 25-mm sampling assemblies with pre-weighed PVC filters can be used.

Desiccate and post-weigh each sample and then calculate total welding fume exposure:
 
net weight (µg) - net weight of blank (µg)
air volume (liters)
= mg/m3

and determine compliance with the 5 mg/m3 TLV for welding fumes. Submit the samples to the laboratory for welding fume/ICP analysis to further characterize the samples.
5.2.1 Place a MCE filter and a cellulose backup pad in each two- or three-piece cassette. Seal each cassette with a gel band.

5.2.2 Calibrate each personal sampling pump with a prepared cassette in-line to approximately 2 L/min flow rate.

5.2.3 Attach prepared cassettes to calibrated sampling pumps (the backup pad should face the pump) and place in appropriate positions on the employee or workplace area. Collect the samples at about 2 L/min flow rates. Minimum sampling times recommended are:
 
Recommended Sampling Times
 
Time Weighted Average Samples 240 min 
Short-Term Exposure Limit Samples 15 min*
Ceiling Samples 15 min 

The analytical sensitivity of a specific analyte may dictate using a larger sampling sampling time.

* When determining compliance with the STEL for beryllium, take 30-min samples.

Note: If soluble compounds (i.e. Cr2+, Cr3+, soluble salts of Al, Fe, Mo, Ni, ZnCl2, etc.) are suspected to be present in the sampled air, take separate samples. Request analysis for the specific compound(s). These samples are analyzed using OSHA Method No. ID-121 and not by this method.


5.2.4 If the filter becomes overloaded while sampling, another filter cassette should be prepared. Consecutive samples using shorter sampling periods should be taken if overloading occurs.

5.2.5 Place plastic end caps on each cassette after sampling.

5.2.6 Attach an OSHA-21 seal around each cassette in such a way as to secure the end caps.
5.3 Sampling Procedure - Wipe Samples
5.3.1 Wear clean, impervious, disposable gloves when taking wipe samples to prevent sample contamination. Change gloves between samples to reduce the possibility of cross contamination.

5.3.2 Moisten Smear Tabs and Whatman filters with deionized water prior to use.

5.3.3 If using a Ghost Wipe remove it from its package and unfold it. Next fold the Ghost Wipe in half and wipe a 10-cm × 10-cm area by starting at the outside edge of the surface, applying firm pressure, wipe the surface and progress towards the center by making concentric squares of decreasing size. Fold wipe in half, with contaminant side in, and wipe the surface again by making concentric squares of decreasing size. Fold the wipe in half, contaminant side in, and wipe surface a third time. If using a Smear Tab or Whatman filter, wipe a 10-cm × 10-cm area by starting at the outside edge of the surface, applying firm pressure, wipe the surface and progress towards the center by making concentric squares of decreasing size. If possible wipe the area at least 3 times.

5.3.4 Fold the wipe sample with exposed side in. 5.3.5 Transfer the wipe sample into a 20-mL scintillation vial and seal with vinyl or electrical tape. Securely wrap an OSHA-21 seal length-wise from vial top to bottom.
5.4 Sampling Procedure - Bulk Samples

In order of laboratory preference, bulk samples may be one of the following:
  1. a high-volume filter sample,
  2. a representative settled dust (i.e. rafter) sample,
  3. a sample of the bulk material in the workplace.
Transfer the bulk material into a 20-mL scintillation vial and seal with vinyl or electrical tape. Securely wrap an OSHA-21 seal length-wise from vial top to bottom.

5.5.Shipment

When other compounds or elements are known or suspected to be present in the sampled air, such information should be transmitted with the sample(s) to the laboratory.
5.5.1 Submit at least one blank sample with each set of air or wipe samples. Blank filter samples should be handled in the same manner as other samples, except no air is drawn through the blank.

5.5.2 Send the samples to the laboratory with the OSHA 91A paperwork requesting ICP analysis.

5.5.3 Bulk samples should be shipped separately from air samples. They should be accompanied by Material Safety Data Sheets if available. Check current shipping restrictions and ship to the laboratory by the appropriate method.
6. Analysis
6.1 Safety Precautions
6.1.1 Prepare 1:1 H2SO4 in DI H2O cautiously.
  1. Use a 1- or 2-L thick-walled, break- and heat-resistant bottle.
  2. Wear thick rubber gloves, plastic apron, labcoat, and face shield.
  3. Add 500 mL DI H2O to the bottle.
  4. Place the bottle over the drain in a sink which has a slot vent to provide ventilation. Begin running cold tap water over the side of the bottle, being careful not to get any tap water in the bottle. Let the level of water rise in the sink to provide cooling of the bottle.
  5. Carefully and slowly begin adding 500 mL concentrated H2SO4 to the DI H2O. Add a small quantity, swirl to mix, and allow contents to cool. Do NOT allow boiling of solution within the container.
  6. After the acid has been added, loosely cap the bottle and allow it to remain in the sink with the water running for at least 15 min. Allow the solution to cool to room temperature.
  7. A thick-walled beaker, Teflon-coated stirring bar, electronic stirrer and a ventilation hood can also be used to prepare 1:1 H2SO4 if precautions are taken to prevent solution overheating and splattering.
6.1.2 Digest all samples within a suitable exhaust hood.

6.1.3 To prevent splattering, add H2O2 (30%) to beakers in 2- to 3-drop groups.

6.1.4 Perchloric acid added to organic substances can produce fires and/or explosions. If HClO4 solutions darken in color while heating, immediately remove beakers from the hotplate and carefully add a small amount of HNO3. Only use HClO4 in exhaust hoods designed and reserved for HClO4 use.

6.1.5 Do not directly view the plasma.

6.1.6 Do not override the rf generator or torch box safety interlocks.
6.2 Equipment
6.2.1 Inductively coupled argon plasma/atomic emission direct-reading spectrometer, cooling unit for torch assembly, computer, and radio-frequency (rf) generator.

6.2.2 Nebulizer.

6.2.3 Automatic sampler.

6.2.4 Peristaltic pumps (optional). Use one pump for automatic sampler rinse. Use the other pump for sample introduction into the nebulizer.

6.2.5 Mass Flow Controller (optional). Use the controller to regulate nebulizer argon flow and sample uptake rate.

6.2.6 Borosilicate glass conical beakers, 125- and 250-mL.

6.2.7 Borosilicate glass volumetric flasks, 25-, 50-, 100-, 250-mL, and 1- or 2-L. Use the larger flasks for standard preparation.

6.2.8 Thick walled, 1- or 2-L heat- and break-resistant bottle.

6.2.9 Mixed cellulose ester filters (0.45-µm pore size) and a filtering apparatus. Use this system to remove any insoluble particulates from sample solutions.

6.2.10 Hot plate capable of reaching 300°C.

6.2.11 Volumetric pipets, glass of various sizes.

6.2.12 Analytical balance (0.01 mg).
6.3 Reagents (reagent grade or better)
6.3.1 Deionized water (DI H2O).

6.3.2 Concentrated sulfuric (H2SO4), hydrochloric (HCl), nitric (HNO3), and perchloric (HClO4) acids.

6.3.3 Prepare 1:1 H2SO4 (V/V) solutions as described in Section 6.1.1

6.3.4 Sample dilution solution or reagent blank (8% HCl/4% H2SO4):

In an exhaust hood, slowly and carefully add 40 mL concentrated H2SO4 to approximately 500 mL of DI H2O contained in a thick-walled, heat- and break-resistant bottle. Gently stir and allow the solution to cool to room temperature. Slowly and carefully add 80 mL concentrated HCl, allow to cool, and dilute to 1 L with DI H2O.

6.3.5 Stock solutions of 1,000 µg/mL for standard preparation of the various elements.

6.3.6 Hydrogen peroxide, (H2O2), 30%.

Note: Some manufacturers use organotin compounds to stabilize H2O2. Since Sn is one of the elements screened, use H2O2 that does not contain this type of stabilizer.


6.3.7 Argon - quality as specified by the ICP manufacturer.
6.4 Standard Preparation

Prepare multielement calibration standards (STD) and continuing calibration verification (CCV) solutions (see Addendum A for examples of combinations) using 1,000 or 10,000 Fg/mL stock solutions. An independent calibration verification (ICV) standard is a mixture of elements whose concentrations are within their respective analytical linear ranges and is used to verify the calibration standards. Whenever possible, prepare the ICV standard from different stock solutions than those used for calibration standards. The ICV standard should contain elements and concentrations reflecting what is expected in the majority of the samples, or problem elements. The final acid concentration of the STD, CCV and ICV standards is 8% HCl/4% H2SO4. These standards should be stable for at least 6 months.

6.5 Sample Preparation

The final acid concentration for the different sample matrices should be 8% HCl/4% H2SO4. All of the elements validated are soluble when using the following acid digestion procedures. Other elements not included in the validated element list (Table 3) should be evaluated for solubility and stability before using these procedures.

Note: Requests for analysis of compounds which have a PEL that specifically addresses the soluble fraction (i.e., Fe, Ni, Mo, etc.) are analyzed using OSHA Method No. ID-121 and not by this method.


Filters, backup pads, wipes, and bulks are prepared by the following procedures:
6.5.1 Mixed-cellulose ester (MCE) membrane filters
  1. If the beakers used for the digestion have not been cleaned using a appropriate automated system, clean the insides of the 125-mL conical beakers by refluxing 1:1 HNO3 using a hot plate in a ventilated hood. Carefully pour the used 1:1 HNO3 into an appropriate labeled container. Allow beakers to cool, then rinse several times with DI H2O and allow to dry. Using forceps, place sample filters in separate labeled and washed beakers (If the backup pad appears contaminated, see Section 6.5.2 below). If the cassette or vial contains loose dust, carefully pour the dust into the beaker. Always rinse the cassette with DI H2O and pour the water into the beaker and wipe out the cassette with a moistened, clean filter and place this filter in the sample beaker.
  2. For samples with air volumes >200 L: Add 4 mL of 1:1 H2SO4, followed by 2 mL of concentrated HNO3 to each beaker containing the filter sample. For samples with air volumes < or = 200 L: Add 2 mL of 1:1 H2SO4, followed by 2 mL of concentrated HNO3.
  3. To facilitate the digestion, allow the filters to sit at least an hour in the 1:1 H2SO4. Add several drops of H2O2 (30%) to each beaker before placing it on the hotplate.
  4. Heat the beakers on a hot plate for approximately 10 min. The solutions should turn brown.
  5. Cautiously add H2O2 in 2- to 3-drop groups until each solution becomes clear, colorless, or slightly yellow (the color is dependent on the concentration and type of analyte present).
  6. Heat several more minutes until dense, white fumes of SO3 just become evident. Remove the beakers from the hotplate and allow to cool.
  7. Slowly and carefully add the following amount of concentrated HCl 

    (CAUTION: SPLATTERING MAY OCCUR IF THE HCl IS ADDED TOO RAPIDLY OR THE H2SO4 SOLUTION IS STILL HOT):


    Acid Addition Data
    Acid Volume
    Air Volume
    4 mL > 200 L
    2 mL < or = 200 L
  1. Rinse the sides of the beakers with DI H2O and return the beakers to the hotplate. Heat the beakers until near boiling to promote solubilization of all elements present. Remove the beakers from the hotplate and allow to cool.
  2. Quantitatively transfer the solutions into volumetric flasks using DI H2O. For samples having air volumes > 200 L, dilute to 50 mL; volumes < or = 200 L, dilute to 25 mL, if the filter contains a lot of material, dilute to 50 mL.
6.5.2 Backup Pads
  1. If the backup pad has been contaminated during collection, digest the pad along with the filter. Also, separately digest and analyze the blank filter with a clean backup pad.
  2. Place each contaminated backup pad and corresponding filter into individual beakers. Allow to sit at least an hour in the appropriate amount of 1:1 H2SO4 (Section 6.5.1, Step 2). Add 10 mL of concentrated HNO3 and proceed as in Section 6.5.1, Step 3 above.
6.5.3 Wipe or Polyvinyl Chloride (PVC) Filter Samples

Polyvinyl chloride filters can be used for sample collection and analysis by ICP. The industrial hygienist may sample for gravimetric determinations of total dust or total welding fumes using PVC filters and also submit these samples for ICP analysis if a sample weight is required. 
  1. If the beakers used for the digestion have not been cleaned using a appropriate automated system, reflux 1:1 HNO3 in 250-mL (for wipes) or 125-mL (for PVC filters) conical beakers, empty and allow to cool. Rinse the beakers several times with DI H2O and allow to dry.
  2. Place each filter or wipe in a separate washed beaker.
  3. Add the appropriate amount of 1:1 H2SO4 as listed below:
    Acid Addition Data
    Acid Volume*

    Sample Type

    8 mL Wipe
    4 mL PVC filter (> 200 L Air Volume)
    2 mL PVC filter (>< or = 200 L Air Volume)
    * Concentrated HCl or 1:1 H2SO4
  1. Add 10 mL concentrated HNO3 to each beaker. Place the beakers on the hotplate.
  2. Add H2O2 in 2- to 3-drop groups. PVC filters and wipes require more H2O2 for digestion than MCE filters.
  3. If HClO4 digestion precautions are followed (Section 6.1.4), 1 to 2 mL of HClO4 can also be used to complete digestion.  The PVC filter will not completely digest if HClO4 is not added; therefore, thoroughly rinse the filter residue with DI H2O during quantitative transfer of the sample solution.
  4. Allow digested samples to cool and carefully add the same volume of concentrated HCl as the 1:1 H2SO4 used in Section 6.5.3, Step 3. above.
  5. Rinse the sides of the beaker with DI H2O and then heat to near boiling.
  6. After beakers have cooled to room temperature, dilute digested wipe solutions to 100 mL. Dilute PVC filter solutions to final volumes as stated in Section 6.5.1, Step 9.
6.5.4 Ghost Wipes
  1. If the beakers used for the digestion have not been cleaned using a appropriate automated system, reflux 1:1 HNO3 in 125-mL conical beakers, empty and allow to cool. Rinse the beakers several times with deionized water and allow them to dry.
  2. Place each Ghost Wipe in a separate washed beaker.
  3. Add 4 mL of 1:1 H2SO4 to each beaker. Let sample sit for 5 minutes.
  4. Add 2 mL of deionized water followed by 2 mL concentrated HNO3 to each beaker. Let samples sit for 15 minutes. After 15 minutes, up to 8 mL more of concentrated HNO3 can be added to facilitate digestion, especially if samples are heavily loaded. Place the beakers on the hotplate.
  5. When solutions turns brown or black cautiously add H2O2 in 2- to 3-drop groups until each solution becomes clear, colorless, or slightly yellow (the color is dependent on the concentration and type of analyte present). Ghost Wipes may require up to 10 mL H2O2 before solution clears.
  6. Heat solutions several more minutes until dense, white fumes of SO3 just become evident. Remove beakers from hotplate and allow them to cool.
  7. After samples have cooled carefully add 4 mL of concentrated HCl to each beaker.
  8. Rinse the sides of the beaker with deionized water and then heat again on hot plate until samples are near boiling.
  9. After beakers have cooled to room temperature, dilute digested Ghost Wipes solutions to 50 mL.
6.5.5 Bulks
  1. Review any available material safety data sheets to determine safe bulk handling. The safety data may also offer a clue as to the aliquot amount needed for adequate detection of the element(s) of interest.
  2. Measure by volume or weight an appropriate aliquot of any liquid bulk sample. Weigh the appropriate amount of any solid bulk sample. Weigh an aliquot of any paint bulk by placing a small amount on a MCE filter, allow to air dry then take the dry weight.

Note: Aliquot amounts of bulks are dependent on the analytical sensitivity, detection limit, and solubility of the material used. If uncertain, a 20- to 50-mg aliquot of a solid material can be taken as a starting point. Make sure the aliquot taken is representative of the entire bulk sample. If needed, use a mortar and pestle to grind any nonhomogeneous particulate bulk samples in an exhaust hood.

After measuring, transfer the aliquot to a previously cleaned or acid-washed 250-mL conical beaker.
  1. Add 20 mL of 1:1 H2SO4 and digest on a hotplate. Hydrogen peroxide (dropwise) and a few mLs of HNO3 can be carefully added to break up the matrix.
     
    Caution: Do not add the HNO3 to wet bulk materials containing organic solvents. Significant reactions could occur.
     
  1. Remove the beaker from the hotplate and allow to cool. Carefully add 20 mL of concentrated HCl and then heat the solution to near boiling.
  2. Allow to cool and quantitatively transfer to a 250-mL volumetric flask. Dilute to volume with DI H2O.
Air, wipe, and bulk samples: If particulates are present in any of the sample solutions, filter this solution through a MCE filter (0.45-µm pore size) and then re-digest the particulate and filter. Save the filtrates for analysis.
6.6 Instrument Startup and Calibration

Follow the manufacturer's instructions for instrument start-up and calibration. An example of ICP operating parameters is shown below. These settings will vary from instrument to instrument:

Gas Used Argon
Gas Flow
(Rotameter settings)
Plasma
Nebulizer
Auxiliary Plasma
12 - 16 L/min
*
0.14 - 0.18 L/min
RF Power Incident
Reflected
1.1 kW
< 5 W
Observation Height Plasma 15 mm above work coil
Integration Time Peak Signal 3 to 10 s
Wash Time Automatic Sampler
Without Automatic Sampler
60 s
10 s
Number Of Exposures Standards & Samples 2 to 10
Nebulizer* Solution Uptake Rate
Pressure
0.8 - 1.6 mL/min
~30 psig
Mass Flow Controller Flow Rate Range varies*
* This flow will vary depending on the type of nebulizer in use.

6.6.1 Profile the instrument before beginning the calibration and analysis. Follow the Standard Operating Procedure (SOP) (8.7) or manufacturer's instructions for computer initialization and profiling.

6.6.2 Obtain a two-point calibration curve by nebulizing the working standards into the plasma and measuring atomic emission intensities. For most instruments, a first-order linear fit of the data is computer calculated and slope and intercept coefficients are obtained. Perform calibrations by following the instrument manufacturer's guidelines.

6.6.3 See Addendum A for the proper sequence of standards and samples during the analysis.
6.7 Analytical Procedure

For more details regarding analytical procedures, refer to the instrument manufacturer's software manual(s) or the SOP (8.7).
6.7.1 If necessary, determine detection limits using the manufacturer's software (if available). These limits normally do not significantly change during short time spans. A general rule is to recalculate detection limits when an integral component (nebulizer, torch, mass flow controller, etc.) of the ICP has been replaced or adjusted. A typical calculation of detection limit (DL) is shown:
 
DL = (K × SDI × C)
(I - Io)
× S

where:
S is Solution volume in mL
K is Degree of confidence (sigma value)*
SDI is Standard deviation of reagent blank intensity (Io.)
C is Concentration of the calibration standard in µg/mL
I is Total intensity of standard containing concentration C
Io is Background intensity (reagent blank)
* In most cases, K=2 or 3 for qualitative and K=10 for quantitative determinations.

Reporting limits may be equal to or larger than the calculated detection limits. Reporting limits should be verified annually for each matrix.

6.7.2 Analysis using an automatic sampler is described below:
  1. Fill automatic sample vials to the minimum sample volume for one analysis and a potential rerun.
  2. Load the automatic sampler with labeled standard and sample vials. A multielement working standard should be analyzed after every 5 to 6 samples. A control standard should be occasionally analyzed to ensure proper instrument operation. If an element or elements contained in the control standard are not within specification (a general rule is to use a value less than ±10 to 15% of the known concentration), the analyst should recalibrate before proceeding with the analysis.
  3. Aspirate each sample or standard for approximately 1 min prior to initiating the exposure cycle. This ensures equilibration in the plasma and minimizes carry-over effects.
  4. Dilute and reanalyze any samples containing elements (both screened and validated) exceeding the working range (Table 2).  In particular, notice the reduced upper limit (8 µg/mL) for lead. Interelement corrections may not be accurate above the working range. Prepare the dilutions by pipetting an appropriate aliquot from the original solution and dilute with 8% HCl/4% H2SO4.
  5. Based on the calibration curve initially obtained, convert the sample intensities to concentrations. Then, using the air volume, solution volume, dilution factor and sample weight, calculate the concentration for each element analyzed as mg/m3 (air samples), total micrograms (wipes), or percentage of total weight (bulks) using the equations shown below.
6.8 Calculations
6.8.1 Total amount of analyte in the sample:
µg A = (µg/mL A) × (mL S) × (DF) (1)

where:
µg A is Total µg of analyte in the sample
µg/mL A is Measured concentration of analyte in sample solution (derived from calibration curve)
mL S is total volume of the solution analyzed
DF is amount of dilution applied to an aliquot of the original solution (ratio of final volume divided by the aliquot volume)
6.8.2 The blank value, if any, is subtracted from each sample:
µgc A = µg A - µgb A (2)

where:
µgc A is µg of analyte, blank corrected
µgb A is µg of analyte in blank

6.8.3 For air samples, the concentration of analyte in the sample is expressed in mg analyte per cubic meter for each element or compound analyzed:
mg/m3 = (µgc A) × (GF)
air volume (L)
(3)

where:
GF is Gravimetric Factor


For those elements having a PEL listed as an oxide, the gravimetric factors for the validated elements are:

1.4298 for Fe2O3       1.2447 for ZnO       1.7852 for V2O5

6.8.4 Convert bulk sample analytes to % composition using:

%(w/w) = (µgc A) (100%)
(sample weight) (1,000 µg/mg)
(4)

where:
µgc A is analyte amount (µg)
Sample wt is aliquot (in mg) of bulk taken in Section 6.5.4
7. Reporting Results
7.1 Air sample results are reported as mg/m3. Results for analytes having a PEL as an oxide are reported as mg/m3 of the oxide.

7.2 Wipe sample concentrations are calculated and reported as total micrograms for each element.

7.3 Bulk sample results are calculated and reported as elemental percent by weight (or volume if liquid aliquots were used). Due to differences in sample matrices between bulks and standards, bulk results are approximate for each element determined. (Elemental values are to be reported for all bulk analyses, do not use a gravimetric factor.)

7.4 Determinations of the screened elements or compounds are not routinely reported. Spectral interference corrections for these analytes are not included and validations have not been performed. If a sample has a screened analyte over the PEL, the analyst should contact her/his supervisor. Additional sampling, or if possible, additional analysis of the original sample should be performed to quantitate the potential overexposure.
8. References
8.1 Occupational Safety and Health Administration Analytical Laboratory: OSHA Analytical Methods Manual (USDOL/OSHA-SLCAL Method No. ID-125). Cincinnati, OH: American Conference of Governmental Industrial Hygienists (Pub. No. ISBN: 0-936712-66-X), 1985.

8.2 Occupational Safety and Health Administration Technical Center: ICP Backup Data Report (ID-125G) by J.C. Septon. Salt Lake City, UT. Revised 1991.

8.3 Occupational Safety and Health Administration Technical Center: ICP Backup Data Report (ARL 3560) by J.C. Septon. Salt Lake City, UT. In progress.

8.4 "Toxic and Hazardous Substances," Code of Federal Regulations Title 29, Pt. 1910.1000, Subpart Z. 1987. pp 676-682.

8.5 National Institute for Occupational Safety and Health: NIOSH Manual of Analytical Methods, 2nd ed., Vol. 7 (DHEW/NIOSH Pub. No. 82-100). Cincinnati, OH, 1981. Method No. 351.

8.6 United States Department of Labor, OSHA: "Memorandum, Sampling for Welding Fumes" by Patricia Clark, Director Designate, Directorate of Compliance Programs. United States Department of Labor, OSHA, Washington, DC, February 14, 1989. [Memo].

8.7 Occupational Safety and Health Administration Analytical Laboratory: ICP Standard Operating Procedure by J.C. Septon. Salt Lake City, UT. 1988 (unpublished).

Table 1
Air Contaminants - OSHA Permissible Exposure Limits*

Element Substance Exposed to PEL
(mg/m3)

TWA CEILING

Ag** Metal and soluble compounds
(as Ag)

0.01

As** Inorganic compounds (as As) See 29 CFR 1910.1018 for applications
Be# Beryllium and compounds
(as Be)

0.002

0.005##
Ca** Calcium oxide 5
Cd Fume
Dust
(See 29 CFR 1910.1027)
0.1
0.2
0.3
0.6
Co Metal dust and fume (as Co) 0.1
Cr Cr metal (as Cr) 1
Cu Fumes (as Cu)
Dusts and mists (as Cu)
0.1
1
Fe Dicyclopentadienyl iron Total dust
Iron oxide fume (as Fe2O3)
15
10
Fe,V Ferrovanadium dust 1
Mg** Magnesium oxide fume Total particulate 15
Mn Mn compounds (as Mn)
Mn fume (as Mn)

5
5
Mo Insoluble compounds (as Mo) Total dust 15
Ni Metal and insoluble
compounds (as Ni)
1
1
Pb Inorganic (see 29 CFR 1910.1025)
Sb Sb and compounds (as Sb) 0.5
Se** Se and compounds (as Se) 0.2
Sn** Inorganic compounds except oxides (as Sn) 2
Te** Te and compounds (as Te) 0.1
Zn Zinc oxide fume
Zinc oxide Total dust
Zinc stearate Total dust
5
15
15

* From reference 8.4
** Elements screened - PELs are listed for information only, because the screened elements are not digested or analyzed using optimum conditions. 
# Beryllium also has a Peak PEL of 0.025 µg/m³.
## Both the Ceiling Limit and the STEL for beryllium are for a maximum 30-min duration.

Note: Compounds having total and respirable dust PELs of 15 and 5 mg/m³ respectively, are normally analyzed gravimetrically. Elements contained in these dust samples can be identified by this or other methods, if necessary.
 
Table 2
Detection Limits* and Upper Limits

Analyte

Qual. Det.
Limit (µg)

Quan. Det.
Limit (µg)

Upper
Limit (µg/mL)

   Ag**    1.1    3.8    **
   Al**    6.8    23.    200
   As**    1.7    5.7    20
   Be    0.013    0.043    5
   Ca**    0.79    2.6    20
   Cd    0.14    0.47    50
   Co    1.2    4.0    100
   Cr    0.40    1.3    50
   Cu    0.64    2.1    50
   Fe    8.9    30.    200
   Mg**    2.1    7.1    20
   Mn    0.061    0.20    15
   Mo    0.52    1.7    100
   Pb    2.1    7.0    8
   Ni    0.59    2.0    100
   Sb    4.2    14.    100
   Se**    3.2    11.    20
   Si**    2.4    8.1    20
   Sn**    3.5    12.    **
   V    0.57    1.9    100
   Zn    0.14    0.47    50
 
* Calculations are based on a 50-mL solution volume and equations listed in Section 6.7.1 Each detection limit is dependent on the spectral wavelength and order used for analysis.
** Screened elements - Limits are approximate - the digestion and analysis are not optimized for these elements.

Both the detection limits and upper limits were determined using ICP1 (JY-32 ICP). Performance may vary from instrument to instrument. Upper limits are the upper linear range for each element. These were determined using a linear model (8.2).
 
Table 3
Precision and Accuracy Data* for Spiked Samples


Element


CV


Bias


Range (µg)

Analytical
Error (± %)

Be 0.010 0.010 0.12-0.48 2.9
Cd1 0.014 -0.005 6-24 3.2
Co 0.020 -0.040 6-24 8.1
Cr2 0.015 -0.074 60-240 10.3
Cu3 0.017 0.054 60-240 8.7
Fe 0.018 -0.012 420-1680 4.8
Mn 0.032 0.077 75-300 14.1
Mo4 0.047 -0.029 225-900 12.3
Ni 0.025 0.017 105-420 6.6
Pb 0.040 0.04 5-20 12.1
Sb 0.014 0.012 60-240 3.9
V 0.045 0.090 3.5-14 18.1
Zn 0.007 0.014 240-960 2.9
 
* Reported values were obtained from ICP1 (ISA JY-32 ICP). Results may vary from instrument to instrument.
The following exceptions were used when calculating spike amounts:
1 PEL for fume (0.1 mg/m3) used
2 PEL for insoluble forms (1 mg/m3) used
3 PEL for dust form (1 mg/m3) was used
4 5 mg/m3 target concentration was used. This was performed because a very large amount of spike would be necessary if the 15 mg/m3 PEL for Mo was used.

CV Coefficient of Variation

Addendum A
 
Instrument Calibration & Quality Control Sequence
QC 
Function
Acronym Frequency Acceptance 
Criteria
Analytes & Nominal Concentrations (ppm)
Initial 
Calibration1
CB At the beginning of each analytical sequence
and
as required by failing performance checks
n/a   
STD-A RSD < 2%
(replicate 
readings)
Target analytes reported to clients:
1 - Be
5 - Cr, Cu, Pb, V
10 - Cd. Co, Mn, Mo, Ni, Sb, Zn
100 - Fe
STD-B Anticipated interfering analytes:
1 - Ag, Pt
10 - Al, As, Ce, Mg, Nb, Se, Sn, Ti
Initial 
Performance 
Checks
ICV Immediately following the initial calibration 90-110% 
Recovery
0.5 - Be
2.5 - Cr, Cu, Pb, V
5 - Cd, Co, Mn, Mo, Ni, Sb, Zn
50 - Fe
CCV Immediately following each calibration event in the analytical sequence
(IB must follow ICS)
0.5 - Be
2.5 - Cr, Cu, Pb, V
5 - Cd, Co, Mn, Mo, Ni, Sb, Zn
50 - Fe
RLV 75-125% 
Recovery
0.002 - Be
0.01 - Cd
0.03 - V
0.05 - Co, Cu, Mn
0.1 - Pb
0.2 - Cr
0.5 - Fe, Mo, Ni, Sb, Zn
ICS 85-115% 
Recovery
(Target 
Analytes 
Only)
0.2 - Be, Cd
1 - Pb, V, Ag
5 - Co, Cr, Co, Mn, Mo, Ni, Sb, Zn, As, Se, Sn
10 - Ce, Nb, Pt
200 - Fe, Al, Mg, Ti
IB |X| < Reporting Limit
(Target 
Analytes Only)
  
Continuing
Performance
Checks
CCV Every 10
field
samples
90-110%
Recovery
0.5 - Be
2.5 - Cr, Cu, Pb, V
5 - Cd, Co, Mn, Mo, Ni, Sb, Zn
50 - Fe
RLV 75-125%
Recovery
0.002 - Be
0.01 - Cd
0.03 - V
0.05 - Co, Cu, Mn
0.1 - Pb
0.2 - Cr
0.5 - Fe, Mo, Ni, Sb, Zn
IB |X| < Reporting Limit
(Target 
Analytes Only)
      
Sequence
Termination
Performance
Checks
CCV At the end
of the
analytical
sequence
90-110%
Recovery
0.5 - Be
2.5 - Cr, Cu, Pb, V
5 - Cd, Co, Mn, Mo, Ni, Sb, Zn
50 - Fe
RLV 75-125%
Recovery
0.002 - Be
0.01 - Cd
0.03 - V
0.05 - Co, Cu, Mn
0.1 - Pb
0.2 - Cr
0.5 - Fe, Mo, Ni, Sb, Zn
IB |X| < Reporting Limit
(Target 
Analytes Only)
    

Term:    STD Calibration Standard(s)
CB Calibration Blank
ICV Independent Calibration Verification (alternate source reference material)
CCV Continuing Calibration Verification
IB Instrument Blank (part of continuing calibration verification)
RVL Reporting Limit Verification
ICS Interference Check Sample
Target Analyte: any analyte that is reported to clients in the final report of results
1The linear calibration range for target analytes may be established/verified for each analytical sequence by analyzing a high level calibration verification standard at the end of the analytical sequence. In order to report sample results that are measured at levels between this high standard and the initial calibration standard, the high standard must exhibit a recovery between 90 and 110%.

Addendum B
Ghost Wipe Backup Data
  1. Backup Data
General background information about the determination of detection limits and reproducibility of the overall procedure is found in the "Evaluation Guidelines for Surface Sampling Methods"1. The Guidelines define analytical parameters, specific laboratory tests, statistical calculations and acceptance criteria.

Sample preparation of Ghost Wipes was performed as described in Section 6.5.4 of OSHA Method ID-125G. Instrument analytical conditions used are described in Section 1.9 of this document. Lot
number of Ghost Wipes used was 9901, manufactured on May 20, 1999.
 
1.1 Detection Limit of the overall procedure (DLOP) and reliable quantitation limit (RQL).

The DLOP is measured as mass per sample. Seven Ghost wipes were spiked with descending increments of analyte. These spiked Ghost Wipes, and a sample blank, were analyzed and the data obtained used to calculate the required parameters (standards error of estimate and the slope) for the calculation of the DLOP.

The RQL is considered the lower limit for precise quantitative measurements. It is determined from the regression line parameters obtained for the calculation of the DLOP, providing 75% to 125% of the analyte is recovered. 

The analyte target, calculated DLOPs, and RQLs for the 13 validated analytes are shown below:
Table 1.1.1
Target Concentrations, DLOPs, and RQLs

analyte and
 wavelength
target concn
 (µg)
DLOP 
(µg) in 50 mL
RQL
 (µg) in 50 mL
recovery at RQL*
 (%)

BE 313.107 4 0.0052 0.017 112.8
Cd 214.440 10 0.053 0.18 94.6
Co 228.616 200 0.32 1.1 101.2
Cr 267.716 1000 1.0 3.4 101.2
Cu 324.752 200 0.45 1.5 106.0
Fe 238.204 2000 1.5 5.1 105.5
Mn 257.610 400 0.29 0.97 101.1
Mo 202.031 1000 0.8 2.7 103.8
Ni 232.003 1000 0.92 3.1 97.5
Pb 220.353 100 0.55 1.8 81.9
Sb 206.836 1000 1.5 5.1 105.8
V 292.402 56 0.08 0.29 103.1
Zn 213.857 800 2.2 7.3 95.4

*Percent recovery at or near the RQL.

Table 1.1.2
Detection Limit of the Overall Procedure for Beryllium
Figure 1.1.2 Plot of data to determine DLOP/RQL for Beryllium. 
        (Y=44.36.7X +2.2)

mass per sample (µg) intensity

0 -7.4
0.012 64.7
0.025 121.9
Figure 1.1.2 Plot of data to determine DLOP/RQL for Beryllium. (Y=44.36.7X +2.2)
0.05 224.5
0.1 436.1
0.15 666.4
0.2 895.1
0.25 1110.4



 
Table 1.1.3
Detection Limit of the Overall Procedure for Cadmium
Figure 1.1.3. Plot of data to determine the DLOP/RQL for Cadmium. 
        (Y=65.2X + 0.7)

mass per sample (µg) intensity

0 0.4
0.031 4.5
0.062 4.6
0.12 9
0.25 15.8
0.38 24.6
0.5 32.5 Figure 1.1.3. Plot of data to determine the DLOP/RQL for Cadmium. (Y=65.2X + 0.7)
0.63 43



 
Table 1.1.4
Detection Limit of the Overall Procedure for Cobalt
Figure 1.1.4. Plot of data to determine DLOP/RQL
          for Cobalt. (Y=42.2X + 0.4)

mass per sample (µg) intensity

0 -2.1
0.62 26.7
1.25 52.9
2.5 104.8
5 206.7
7.5 318.5 Figure 1.1.4. Plot of data to determine DLOP/RQL for Cobalt. (Y=42.2X + 0.4)
10 428.2
12.5 519.8



 
Table 1.1.5
Detection Limit of the Overall Procedure for Chromium
Figure 1.1.5. Plot of data to determine DLOP/RQL
          for Chromium. (Y=215.6X - 6.5)

mass per sample (µg) intensity

0 46.3
3.1 673.8
6.2 1332.1
12.5 2749
25 5258
37.5 8015 Figure 1.1.5. Plot of data to determine DLOP/RQL for Chromium. (Y=215.6X - 6.5)
50 10769.5
62.5 13546.3



 
Table 1.1.6
Detection Limit of the Overall Procedure for Copper
Figure 1.1.6. Plot of data to determine DLOP/RQL
          for Copper. (Y=136.4X + 648.9)

mass per sample (µg) intensity

0 1050.3
0.62 1404
1.3 1904.2
2.5 2687.7
5 4444.8
7.5 6128.2
10 7844.6 Figure 1.1.6. Plot of data to determine DLOP/RQL for Copper. (Y=136.4X + 648.9)
12.5 9893.2



 
Table 1.1.7
Detection Limit of the Overall Procedure for Iron
Figure 1.1.7. Plot of data to determine DLOP/RQL
          for Iron. (Y= 136.4X + 648.9)

mass per sample (µg) intensity

0 699.2
6.2 1546.4
12.5 2371.5
25 4035.6
50 7338.3
75 10830.9
100 14309.3 Figure 1.1.7. Plot of data to determine DLOP/RQL for Iron. (Y= 136.4X + 648.9)
125 17759.7



 
Table 1.1.8
Detection Limit of the Overall Procedure for Manganese
Figure 1.1.8. Plot of data to determine DLOP/RQL
          for Manganese. (Y= 1924.2X + 124.5)

mass per sample (µg) intensity

0 166.6
1.2 2552.4
2.5 5015.1
5 9899.9
10 19028.4
15 28853.3
20 38573.7 Figure 1.1.8. Plot of data to determine DLOP/RQL for Manganese. (Y= 1924.2X + 124.5)
25 48431.3



 
Table 1.1.9
Detection Limit of the Overall Procedure for Molybdenum
Figure 1.1.9. Plot of data to determine DLOP/RQL
          for Molybdenum. (Y= 10.3X - 1.1)

mass per sample (µg) intensity

0 -2.7
3.1 32.3
6.2 63.2
12.5 130.3
25 251.6
37.5 388
50 515.2 Figure 1.1.9. Plot of data to determine DLOP/RQL for Molybdenum. (Y= 10.3X - 1.1)
62.5 641.4



 
Table 1.1.10
Detection Limit of the Overall Procedure for Nickel
Figure 1.1.10. Plot of data to determine
          DLOP/RQL for Nickel. (Y= 20.6X + 3.0)

mass per sample (µg) intensity

0 0.9
3.1 65.5
6.2 135.7
12.5 265.1
25 508.5
37.5 770.4
50 1040.4 Figure 1.1.10. Plot of data to determine DLOP/RQL for Nickel. (Y= 20.6X + 3.0)
62.5 1284



 
Table 1.1.11
Detection Limit of the Overall Procedure for Lead
Figure 1.1.11. Plot of data to determine
          DLOP/RQL for Lead. (Y= 5.2X - 1.0)

mass per sample (µg) intensity

0 0.3
0.31 -0.4
0.62 2.7
1.25 4.3
2.5 11.6
3.8 19.5
5 24.8 Figure 1.1.11. Plot of data to determine DLOP/RQL for Lead. (Y= 5.2X - 1.0)
3.2 31.5



 
Table 1.1.12
Detection Limit of the Overall Procedure for Antimony
Figure 1.1.12. Plot of data to determine
          DLOP/RQL for Antimony. (Y= 2.4X - 0.4)

mass per sample (µg) intensity

0 -1.3
3.1 6
6.2 15.2
12.5 28.8
25 60.8
37.5 88.1
50 116.6 Figure 1.1.12. Plot of data to determine DLOP/RQL for Antimony. (Y= 2.4X - 0.4)
62.5 146.3



 
Table 1.1.13
Detection Limit of the Overall Procedure for Vanadium
Figure 1.1.13 Plot of data to
          determine DLOP/RQL for Vanadium. (Y= 165.9X + 4.6)

mass per sample (µg) intensity

0 5.7
0.17 39.8
0.35 64.5
0.7 114.6
1.4 230.2
2.1 352.4
2.8 472.4 Figure 1.1.13 Plot of data to determine DLOP/RQL for Vanadium. (Y= 165.9X + 4.6)
3.5 586.7



 
Table 1.1.14
Detection Limit of the Overall Procedure for Zinc
Figure 1.1.14. Plot of data to determine
          DLOP/RQL for Zinc (Y= 76.0X + 725.7)

mass per sample (µg) intensity

0 805.8
2.5 879.8
5 1088.1
10 1445.5
20 2201.2
30 3046.4 Figure 1.1.14. Plot of data to determine DLOP/RQL for Zinc (Y= 76.0X + 725.7)
40 3825.4
50 4482.3



1.2 Storage Test

Storage samples were prepared by liquid-spiking Ghost Wipes at the target concentration. Twelve storage samples were prepared. Three samples were analyzed on the day prepared. Nine of the samples were stored at ambient temperature (about 22ºC). At 5-day intervals three samples were analyzed. Results were blank corrected.
 
Table 1.2.1
Storage Test for Beryllium
Figure 1.2.1. Storage test for Beryllium.

time (days) recovery (%)

0 90.2 91.3 92.8
5 90.7 93.7 91.2
10 90.1 88.9 92.0 Figure 1.2.1. Storage test for Beryllium.
15 91.1 91.3 91.9



 
Table 1.2.2
Storage Test for Cadmium
Figure 1.2.2. Storage test for Cadmium.

time (days) recovery (%)

0 91.0 92.6 93.3
5 95.8 97.9 96.8
10 96.8 94.7 97.7 Figure 1.2.2. Storage test for Cadmium.
15 96.0 96.0 96.4



 
Table 1.2.3
Storage Test for Cobalt
Figure 1.2.3. Storage test for Cobalt.

time (days) recovery (%)

0 94.8 95.9 96.7
5 93.6 96.6 94.3
10 93.2 92.7 95.6 Figure 1.2.3. Storage test for Cobalt.
15 97.4 98.4 97.4



 
Table 1.2.4
Storage test for Chromium
Figure 1.2.4. Storage test for Chromium.

time (days) recovery (%)

0 96.7 100.1 98.1
5 95.6 98.7 97.6
10 96.4 94.1 97.0 Figure 1.2.4. Storage test for Chromium.
15 96.7 98.5 97.0



 
Table 1.2.5
Storage Test for Copper
Figure 1.2.5. Storage test for Copper.

time (days) recovery (%)

0 95.7 96.6 98.2
5 95.9 97.8 96.3
10 96.3 93.8 96.6 Figure 1.2.5. Storage test for Copper.
15 96.8 97.8 96.8



 
Table 1.2.6
Storage Test for Iron
Figure 1.2.6. Storage test for Iron.

time (days) recovery (%)

0 97.5 98.6 100.3
5 97.1 99.0 97.7
10 97.7 95.9 98.8 Figure 1.2.6. Storage test for Iron.
15 98.7 99.9 99.0



 
Table 1.2.7
Storage Test for Manganese
Figure 1.2.7. Storage test for Manganese.

time (days) recovery (%)

0 95.2 98.5 96.8
5 94.6 97.5 96.5
10 96.0 93.8 96.6 Figure 1.2.7. Storage test for Manganese.
15 96.9 98.7 97.2



 
Table 1.2.8
Storage Test for Molybdenum
Figure 1.2.8. Storage test for Molybdenum.

time (days) recovery (%)

0 96.0 97.0 98.0
5 96.3 97.0 95.0
10 94.7 93.6 96.5 Figure 1.2.8. Storage test for Molybdenum.
15 95.3 95.8 95.8



 
Table 1.2.9
Storage Test for Nickel
Figure 1.2.9. Storage test for Nickel.

time (days) recovery (%)

0 94.5 97.7 95.1
5 94.2 98.1 95.0
10 94.5 93.3 96.2 Figure 1.2.9. Storage test for Nickel.
15 94.4 94.6 95.3



 
Table 1.2.10
Storage Test for Lead
Figure 1.2.10. Storage test for Lead.

time (days) recovery (%)

0 93.6 94.8 96.3
5 93.0 96.6 95.7
10 95.2 93.4 96.7 Figure 1.2.10. Storage test for Lead.
15 94.3 95.3 95.0



 
Table 1.2.11
 Storage Test for Antimony
Figure 1.2.11. Storage test for Antimony.

time (days) recovery (%)

0 85.8 85.5 90.1
5 86.9 88.2 85.6
10 78.2 81.7 86.6 Figure 1.2.11. Storage test for Antimony.
15 85.5 89.6 89.0



 
Table 1.2.12
Storage Test for Vanadium
Figure 1.2.12. Storage test for Vanadium.

time (days) recovery (%)

0 91.3 93.6 92.4
5 91.2 94.4 91.7
10 91.0 89.5 91.6 Figure 1.2.12. Storage test for Vanadium.
15 91.1 90.7 91.2



 
Table 1.2.13
Storage Test for Zinc
Figure 1.2.13. Storage test for Zinc.

time (days) recovery (%)

0 90.0 90.9 91.4
5 89.9 92.8 90.7
10 89.6 88.7 91.4 Figure 1.2.13. Storage test for Zinc.
15 90.3 91.4 90.9



1.3 Sampler Removal Efficiency

Six 100-cm2 glass plates were liquid-spiked at the target concentrations and allowed to dry. Samples were collected from each surface by placing a Ghost Wipe folded in half at an outside edge of the glass plate and progressing towards the center making concentric squares of decreasing size while applying firm pressure. The Ghost Wipe was folded in half with the contaminant side in and the glass plate was wiped a second time. The Ghost Wipe was again folded in half and the surface wiped a third time. Results were blank corrected.
 
Table 1.3.1
Sampler Removal Efficiency Data for Beryllium on Ghost Wipes
  Table 1.3.2
Sampler Removal Efficiency Data for Cadmium on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
4 3.770 94.2   10 9.300 93.0
4 3.755 93.9   10 9.168 91.6
4 3.938 98.4   10 9.625 96.2
4 3.880 97.0   10 9.535 95.4
4 3.848 96.0   10 9.595 96.0
4 3.785 84.4   10 8.330 83.3

 


 
Table 1.3.3
Sampler Removal Efficiency Data for Cobalt on Ghost Wipes
Table 1.3.4
Sampler Removal Efficiency Data for Chromium on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
200 182.1 91.0   1000 964.5 96.4
200 182.0 91.0   1000 889.5 88.9
200 190.6 95.3   1000 1001.5 100.1
200 187.6 93.8   1000 917.5 91.7
200 187.8 93.9   1000 992.0 99.2
200 162.8 81.4   1000 927.0 92.7

 


 
Table 1.3.5
Sampler Removal Efficiency Data for Copper on Ghost Wipes
  Table 1.3.6
Sampler Removal Efficiency Data for Iron on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
200 194.1 97.0   2000 1914 95.7
200 193.6 96.8   2000 1913 95.6
200 200.7 100.4   2000 1987 99.4
200 195.6 97.9   2000 1940 97.0
200 197.3 98.6   2000 1957 97.8
200 172.5 86.2   2000 1704 85.2

 


 
Table 1.3.7
Sampler Removal Efficiency Data for Manganese on Ghost Wipes
  Table 1.3.8
Sampler Removal Efficiency Data for Molybdenum on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
400 385.1 96.3   1000 892.0 89.2
400 356.8 89.2   1000 698.5 69.8
400 400.0 100.0   1000 791.0 79.1
400 367.1 91.8   1000 780.5 78.0
400 395.7 98.9   1000 724.5 72.4
400 371.1 92.8   1000 749.0 74.9

 


 
Table 1.3.9
Sampler Removal Efficiency Data for Nickel on Ghost Wipes
  Table 1.3.10
Sampler Removal Efficiency Data for Lead on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
1000 913.5 91.4   100 90.95 91.0
1000 843.0 84.3   100 89.00 89.0
1000 955.0 95.5   100 93.60 93.6
1000 881.0 88.1   100 91.55 91.6
1000 941.5 94.2   100 92.75 92.8
1000 875.0 87.5   100 80.40 80.4

 


 
Table 1.3.11
Sampler Removal Efficiency Data for Antimony on Ghost Wipes
  Table 1.3.12
Sampler Removal Efficiency Data for Vanadium on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
1000 809.5 81.0   56 52.08 93.0
1000 654.5 65.4   56 49.41 88.2
1000 733.0 73.3   56 54.23 96.8
1000 717.5 71.8   56 50.23 89.7
1000 698.5 69.8   56 52.43 93.6
1000 690.5 69.0   56 50.98 91.0

 



Table 1.3.13
Sampler Removal Efficiency Data for Zinc on Ghost Wipes

theoretical (µg/surface) recovered (µg/sample) recovery (%)

800 710.7 88.8
800 712.2 89.0
800 754.2 94.3
800 739.2 92.4
800 735.2 91.9
800 641.7 80.2



1.4 Analytical Method Recovery and Stability of Digested Samples
1.4.1 Analytical Method Recovery

Analytical method recovery (AMR) was determined by liquid-spiking Ghost Wipes with the analytes at the RQL, 0.1, 1.0, and 10 times the target concentrations. These samples were stored overnight at ambient temperature and then analyzed. Results were blank corrected.
 
Table 1.4.1.1
Analytical Method Recovery of Beryllium from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 0.017 114.7 82.4 94.1 82.4 93.4
0.1 0.4 95.6 99.5 96.1 97.4 97.2
1.0 4 94.5 95.1 90.6 94.4 93.6
10 40 92.2 92.9 93.6 94.4 93.3
AMR 94.4



 
Table 1.4.1.2
Analytical Method Recovery of Cadmium from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 0.18 83.3 86.1 86.1 80.6 84.0
0.1 1 99.5 102.5 98.0 99.0 99.8
1.0 10 99.4 99.80 96.5 99.4 98.8
10 100 98.3 100.4 102.4 102.5 100.9
AMR 95.9



 
Table 1.4.1.3
Analytical Method Recovery of Cobalt from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 1.1 105.9 92.7 94.1 97.7 97.6
0.1 20 99.2 101.9 100.2 101.1 100.6
1.0 200 98.2 98.1 93.7 97.7 96.9
10 2000 96.6 97.6 98.2 99.3 97.9
AMR 98.2



 
Table 1.4.1.4
Analytical Method Recovery of Chromium from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 3.4 116.9 102.5 107.5 107.9 108.7
0.1 100 98.8 102.9 99.8 101.6 100.8
1.0 1000 99.3 98.9 95.3 99.1 98.2
10 10000 96.8 99.3 101.0 101.6 99.7
AMR 101.8



 
Table 1.4.1.5
Analytical Method Recovery of Copper from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 1.5 110.0 111.7 100.0 89.7 102.8
0.1 20 99.8 102.7 101.4 101.0 101.2
1.0 200 98.0 97.4 97.4 97.4 96.6
10 2000 94.8 97.5 99.4 99.4 97.7
AMR 99.6

 
Table 1.4.1.6
Analytical Method Recovery of Iron from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 5.1 131.9 112.9 107.4 93.0 111.3
0.1 200 102.3 106.2 102.9 104.2 103.9
1.0 2000 101.2 100.8 97.0 101.1 100.0
10 20000 98.5 101.7 103.8 103.8 102.0
AMR 104.3



 
Table 1.4.1.7
Analytical Method Recovery of Manganese from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 0.97 121.0 107.4 137.7 165.6 132.9
0.1 40 99.2 103.0 100.3 101.9 101.1
1.0 400 99.1 98.6 95.1 98.7 97.9
10 4000 96.4 99.0 100.7 101.2 99.3
AMR 107.8



 
Table 1.4.1.8
Analytical Method Recovery of Molybdenum from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 2.7 122.6 100.0 108.2 96.3 106.8
0.1 100 101.8 103.5 102.2 103.0 102.6
1.0 1000 98.9 98.7 94.6 98.5 97.7
10 1000 97.4 98.4 98.8 99.8 98.6
AMR 101.4



 
Table 1.4.1.9
Analytical Method Recovery of Nickel from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 3.1 122.1 105.5 121.1 106.1 113.7
0.1 10 98.0 101.0 99.4 99.6 99.5
1.0 100 98.7 98.2 94.7 97.4 97.2
10 1000 96.9 97.7 97.8 99.1 97.9
AMR 102.1



 
Table 1.4.1.10
Analytical Method Recovery of Lead from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 1.8 53.9 65.0 80.6 67.2 66.7
0.1 10 90.7 93.6 101.0 104.0 97.3
1.0 100 98.8 98.8 94.5 98.5 97.6
10 1000 96.6 99.8 101.3 102.4 100.0
AMR 90.4



 
Table 1.4.1.11
Analytical Method Recovery of Antimony from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 5.1 76.9 59.8 37.1 47.8 55.4
0.1 100 90.9 90.6 90.6 92.5 91.2
1.0 1000 92.3 92.1 89.2 91.7 91.3
10 10000 88.7 85.9 93.2 94.5 90.6
AMR 82.1



 
Table 1.4.1.12
Analytical Method Recovery of Vanadium from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 0.29 94.8 86.2 96.6 101.7 94.8
0.1 5.6 93.0 96.8 94.2 97.2 95.3
1.0 56 94.6 93.9 91.1 93.3 93.2
10 560 92.6 93.6 93.9 94.4 93.6
AMR 94.2



 
Table 1.4.1.13
Analytical Method Recovery of Zinc from Ghost Wipes

level sample number
× target concn µg per sampler 1 2 3 4 mean

RQL 7.3 125.8 132.7 104.6 91.1 113.6
0.1 80 92.3 96.8 91.7 95.4 94.0
1.0 800 93.6 93.2 89.6 92.9 92.3
10 8000 93.5 92.6 93.2 94.1 93.4
AMR 98.3

 
1.4.2 Stability of Digested Samples

Stability of the digested samples were investigated by reanalyzing the four 1.0 times the target concentration samples seven days after initial analysis. After the original analysis was performed the samples were stored at ambient temperature in the 50 mL volumetric flasks in which they were brought to volume in. For the second analysis new aliquots were taken from each volumetric. Results were blank corrected.

 
Table 1.4.2.1
Stability of Digested Samples for Beryllium
  Table 1.4.2.2
Stability of Digested Samples for Cadmium

 
initial (%) after 7 days (%) difference (%)   initial (%) after 7 days (%) difference (%)

 
94.5 91.9 2.9   99.4 97.2 2.2
95.1 92.3 2.8   99.8 98.4 1.4
90.6 87.3 3.3   96.5 94.0 2.5
94.4 9191 3.3   99.4 97.9 1.5

 


 
Table 1.4.2.3
Stability of Digested Samples for Cobalt
  Table 1.4.2.4
Stability of Digested Samples for Chromium

 
initial (%) after 7 days (%) difference (%)   initial (%) after 7 days (%) difference (%)

 
98.2 98.3 0.1   99.3 97.8 1.5
98.1 98.7 0.6   98.9 97.2 1.7
93.7 94.0 0.3   95.3 93.4 1.9
97.7 97.7 0.0   99.1 97.2 1.9

 


 
Table 1.4.2.5
Stability of Digested Samples for Copper
  Table 1.4.2.6
Stability of Digested Samples for Iron

 
initial (%) after 7 days (%) difference (%)   initial (%) after 7 days (%) difference (%)

 
98.0 96.8 1.2   101.2 99.2 1.0
97.4 95.9 1.5   100.8 98.6 2.2
93.4 91.9 1.5   97.0 94.1 2.9
97.4 95.8 1.6   101.1 98.7 2.4

 



Table 1.4.2.7
Stability of Digested Samples for Manganese
  Table 1.4.2.8
Stability of Digested Samples for Molybdenum

 
initial (%) after 7 days (%) difference (%)   initial (%) after 7 days (%) difference (%)

 
99.0 97.4 1.6   98.9 99.2 0.3
98.6 96.6 2.0   98.7 99.8 1.1
95.1 93.0 2.1   94.6 99.8 5.2
98.7 96.6 2.1   98.5 98.6 0.1

 


Table 1.4.2.9
Stability of Digested Samples for Nickel
  Table 1.4.2.10
Stability of Digested Samples for Lead

 
initial (%) after 7 days (%) difference (%)   initial (%) after 7 days (%) difference (%)

 
98.7 96.6 2.1   98.8 97.0 1.8
98.2 96.8 1.9   98.8 97.6 1.2
94.7 92.4 2.3   94.5 94.2 0.3
97.4 95.4 2.0   98.5 98.2 0.3

 


Table 1.4.2.11
Stability of Digested Samples for Antimony
  Table 1.4.2.12
Stability of Digested Samples for Vanadium

 
initial (%) after 7 days (%) difference (%)   initial (%) after 7 days (%) difference (%)

 
92.3 93.2 0.9   94.6 92.1 2.5
92.1 93.7 1.6   93.9 92.0 1.9
89.2 89.9 0.7   91.0 87.3 3.7
91.7 93.6 1.9   93.3 90.3 3.0

 


Table 1.4.2.13
Stability of Digested Samples for Zinc

initial (%) after 7 days (%) difference (%)

93.6 93.5 0.1
93.2 93.9 0.7
89.6 89.6 0.0
92.9 92.7 0.2



1.5 Reproducibility
1.5.1 Sampling Reproducibility Six 100-cm2 glass plates were liquid-spiked at the target concentrations and allowed to dry. Two chemist, other than the one developing the method,
conducted surface sampling. Results were blank corrected.

 
Table 1.5.1
Sampling Reproducibility Data for Beryllium on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

4 3.821 95.5 3.621 90.5
4 3.788 94.7 3.646 91.2
4 3.687 92.2 3.678 91.9
4 3.973 99.3 3.640 91.0
4 4.023 100.6 3.711 92.8
4 3.899 97.5 3.599 90.0



 
Table 1.5.2
Sampling Reproducibility Data for Cadmium on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

10 9.615 96.2 9.480 94.8
10 9.545 95.4 9.520 95.2
10 9.310 93.1 9.510 95.1
10 9.865 98.6 9.550 95.5
10 10.06 100.6 9.665 96.6
10 9.805 98.0 9.390 93.9



 
Table 1.5.3
Sampling Reproducibility Data for Cobalt on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

200 182.1 91.1 183.5 91.8
200 179.5 89.7 185.5 92.9
200 173.3 86.6 185.4 92.7
200 187.6 93.8 185.0 92.5
200 190.5 95.2 188.2 94.1
200 184.0 92.0 182.5 91.2



 
Table 1.5.4
Sampling Reproducibility Data for Chromium on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

1000 976.0 97.6 918.0 91.8
1000 981.0 87.1 956.0 95.6
1000 905.5 90.6 944.5 94.4
1000 991 99.1 935.0 93.5
1000 1025 102.5 980.5 98.0
1000 1012 101.2 954.5 95.4



 
Table 1.5.5
Sampling Reproducibility Data for Copper on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

200 196.0 98.0 189.5 94.8
200 193.9 96.9 190.4 95.2
200 185.1 92.5 189.6 94.8
200 198.9 99.5 188.2 94.0
200 202.3 101.2 190.7 95.3
200 195.4 97.7 185.6 92.7



 
Table 1.5.6
Sampling Reproducibility Data for Iron on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

2000 1961 98.1 1933 96.6
2000 1939 97.0 1949 97.5
2000 1838 91.9 1948 97.4
2000 2002 100.0 1936 96.8
2000 2038 101.9 1962 98.1
2000 1975 98.7 1909 95.5



 
Table 1.5.7
Sampling Reproducibility Data for Manganese on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

400 390.5 97.6 369.0 92.3
400 392.4 98.1 383.7 95.9
400 363.5 90.9 379.0 94.8
400 396.2 99.1 374.8 93.7
400 409.1 102.2 391.8 98.0
400 403.3 100.8 382.6 95.6



 
Table 1.5.8
Sampling Reproducibility Data for Molybdenum on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

1000 737.5 73.8 906.0 90.6
1000 862.0 86.2 932.0 93.2
1000 803.5 80.4 952.0 95.2
1000 934.0 93.4 908.0 90.7
1000 839.0 83.9 970.5 97.0
1000 929.5 93.0 938.5 93.8



 
Table 1.5.9
Sampling Reproducibility Data for Nickel on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

1000 925.0 92.5 895.5 89.6
1000 928.0 92.8 932.5 93.2
1000 875.5 87.6 920.5 92.0
1000 945.0 94.5 915.0 91.5
1000 967.0 96.7 959.0 95.9
1000 959.0 95.9 936.0 93.6



 
Table 1.5.10
Sampling Reproducibility Data for Lead on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

100 94.55 94.6 92.65 92.6
100 92.30 92.3 93.3 93.3
100 89.45 89.5 92.9 92.9
100 96.15 96.2 92.4 92.4
100 97.10 97.1 94.6 94.6
100 94.95 95.0 91.6 91.6



 
Table 1.5.11
Sampling Reproducibility Data for Antimony on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

1000 757.0 75.7 751.5 75.2
1000 836.0 83.6 780.5 78.0
1000 813.0 81.3 797.5 79.8
1000 911.5 91.2 814.5 81.4
1000 823.0 82.3 882.5 88.2
1000 925.0 92.5 827.5 82.8



 
Table 1.5.12
Sampling Reproducibility Data for Vanadium on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

56 52.58 93.9 48.54 86.7
56 51.68 92.3 50.88 90.9
56 49.37 88.2 50.78 90.7
56 53.28 95.2 50.48 90.2
56 54.38 97.1 52.48 93.7
56 53.83 96.1 51.23 91.5



 
Table 1.5.13
Sampling Reproducibility Data for Zinc on Ghost Wipes

  Chemist 1 Chemist 2

theoretical (µg/surface) recovered (µg/sample) recovery (%) recovered (µg/sample) recovery (%)

800 725.5 90.7 729.2 91.2
800 720.7 90.1 727.7 91.0
800 697.7 87.2 742.2 92.8
800 750.7 93.8 731.2 91.4
800 754.7 94.3 751.7 94.0
800 732.7 91.6 728.2 91.0



1.5.2 Analytical Reproducibility

Six samples were prepared by spiking media in the same manner that was used in the preparation of samples for the storage study. The samples were submitted to the OSHA SLTC for analysis and the samples were analyzed by a chemist other than the one developing the method. The samples were analyzed after being stored for 15 days at ambient temperature. Results were blank corrected.
 
Table 1.5.2.1
Analytical Reproducibility Data for Beryllium on Ghost Wipes
  Table 1.5.2.2
Analytical Reproducibility Data for Cadmium on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
4 3.767 94.2   10 10.10 101.0
4 3.903 97.6   10 10.30 103.0
4 3.958 99.0   10 10.46 104.6
4 4.008 100.2   10 10.74 107.4
4 4.024 100.6   10 10.50 105.0
4 3.892 97.3   10 10.34 103.4

 


 
Table 1.5.2.3
Analytical Reproducibility Data for Cobalt on Ghost Wipes
  Table 1.5.2.4
Analytical Reproducibility Data for Chromium on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
200 193.8 96.9   1000 97.3 97.3
200 199.4 99.7   1000 1004 100.4
200 201.3 100.6   1000 1025 102.5
200 205.2 102.6   1000 1033 103.3
200 203.9 102.0   1000 1016 101.6
200 199.2 99.6   1000 1006 100.6

 


 
Table 1.5.2.5
Analytical Reproducibility Data for Copper on Ghost Wipes
  Table 1.5.2.6
Analytical Reproducibility Data for Iron on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
200 193.0 96.5   2000 2016 100.8
200 198.0 99.0   2000 2070 103.5
200 202.1 101.0   2000 2119 106.0
200 203.0 101.5   2000 2134 106.7
200 202.7 101.4   2000 2104 105.2
200 196.4 98.2   2000 2069 103.4

 


 
Table 1.5.2.7
Analytical Reproducibility Data for Manganese on Ghost Wipes
  Table 1.5.2.8
Analytical Reproducibility Data for Molybdenum on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
400 392.4 98.1   1000 982.4 98.2
400 404.4 101.1   1000 879.9 88.0
400 412.6 103.2   1000 1157 115.7
400 415.6 103.9   1000 1040 104.0
400 409.9 102.5   1000 1043 104.3
400 404.8 101.2   1000 1016 101.6

 


 
Table 1.5.2.9
Analytical Reproducibility Data for Nickel on Ghost Wipes
  Table 1.5.2.10
Analytical Reproducibility Data for Lead on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
1000 955.1 95.5   100 96.10 96.1
1000 983.6 98.4   100 97.75 97.8
1000 990.1 99.01   100 98.00 98.0
1000 1005 100.5   100 101.2 101.2
1000 997.6 99.8   100 99.6 99.6
1000 981.6 98.16   100 97.85 97.8

 


 
Table 1.5.2.11
Analytical Reproducibility Data for Antimony on Ghost Wipes
  Table 1.5.2.12
Analytical Reproducibility Data for Vanadium on Ghost Wipes

 
theoretical (µg/surface) recovered (µg/sample) recovery (%)   theoretical (µg/surface) recovered (µg/sample) recovery (%)

 
1000 907.4 90.7   56 51.53 92.0
1000 729.9 73.0   56 53.55 95.6
1000 1107 111   56 53.85 96.2
1000 942.4 94.2   56 54.60 97.5
1000 943.4 94.3   56 54.80 97.9
1000 917.9 91.8   56 53.50 95.5

 



Table 1.5.2.13
Analytical Reproducibility Data for Zinc on Ghost Wipes

theoretical (µg/surface) recovered (µg/sample) recovery (%)

800 733.4 91.7
800 751.9 94.0
800 761.4 95.2
800 771.9 96.5
800 770.9 96.4
800 750.9 93.9

1.6 Interferences
1.6.1 Media, Reagents, and Surface.

Six blank Ghost Wipes were analyzed, after each being used to wipe a separate cleaned glass plate, to determine interferences due to contamination from the glass surface, media, and reagents.
 
Table 1.6.1.1
Contamination to Analysis from the Media and Reagents (µg found)

analyte wipe 1 wipe 2 wipe 3 wipe 4 wipe 5 wipe 6 average

Be 0.009 0.004 0.000 0.008 0.008 0.008 0.006
Cd 0.000 0.015 0.070 0.000 0.000 0.000 0.014
Co 0.090 0.060 0.100 0.000 0.020 0.035 0.051
Cr 0.030 0.015 0.000 0.09 0.020 0.100 0.042
Cu 1.690 1.190 1.040 1.010 1.280 1.355 1.261
Fe 4.900 3.265 3.140 3.475 3.840 4.795 3.902
Mn 0.103 0.022 0.021 0.020 0.037 0.026 0.038
Mo 0.000 0.000 0.000 0.000 0.060 0.075 0.022
Ni 0.000 0.000 0.000 0.070 0.000 0.000 0.012
Pb 0.430 0.000 0.000 0.515 0.000 0.000 0.158
Sb 0.000 0.435 0.000 0.000 0.000 0.000 0.072
V 0.040 0.000 0.015 0.020 0.030 0.000 0.018
Zn 13.88 8.755 8.300 6.065 9.080 9.560 9.273



Six blank Ghost Wipes were analyzed, after each being used to wipe a separate cleaned glass plate, to determine interferences due to contamination from the glass surface, media, and reagents.
 
Table 1.6.1.2
Contamination to Analysis from the Glass Surface, Media and Reagents (µg found)

analyte wipe 1 wipe 2 wipe 3 wipe 4 wipe 5 wipe 6 average

Be 0.000 0.000 0.000 0.000 0.002 0.000 0.000
Cd 0.030 0.020 0.020 0.005 0.005 0.020 0.017
Co 0.090 0.055 0.090 0.075 0.000 0.145 0.076
Cr 0.155 0.355 0.220 0.070 0.370 0.370 0.257
Cu 1.325 1.170 1.015 1.040 1.340 1.405 1.216
Fe 4.865 5.130 4.425 4.170 6.200 6.130 5.153
Mn 0.132 0.198 0.138 0.088 0.120 0.205 0.147
Mo 0.125 0.355 0.410 0.000 0.000 0.165 0.176
Ni 0.440 0.450 0.470 0.355 0.305 0.675 0.449
Pb 0.000 0.000 0.335 0.245 0.640 0.120 0.223
Sb 1.390 0.950 0.000 0.360 0.525 1.240 0.744
V 0.105 0.055 0.040 0.000 0.020 0.015 0.039
Zn 21.59 12.30 11.07 14.79 12.07 9.970 13.63



1.6.2 Spectral Interferences

The following Inter-Element Corrections (IEC) were used to correct for spectral interferences:

Table 1.6.2.1
Radial ICP IEC Factors a,b,c
analyte & wavelength interfering analytes
Co Cr Cu Fe Mn Mo Ni Ti V
Cd 313.107 - - - 0.0576 - - - - -
Co 214.44 - - - - - - 0.1681 1.6467 -
Cr 228.616 - - - - 0.2 - - - -
Cu 267.716 - - - - - 0.4168 - - -
Fe 238.204 - 0.0478 - - - - - - -
Ni 232.003 - 47.35 - - - 6.187 - - -
Pb 220.353 - - - - - - - - -
Sb 206.836 0.1 11.628 - - - - - - -
V 292.402 0.7907 - - - - - - 0.8331 -
Zn 213.857 - - 1.329 0.0518 - - 4.691 0.2 -
  1. The IEC factor2 is the apparent analyte concentration in ppb divided by the interferent concentration in ppm and is calculated as follows:
IEC Factor = Apparent Analyte Cocnc (ppb)
Interferent Concn (ppm)

Where the apparent analyte concentration is the connection of the interferent measured at the analyte wavelength in the absence of the analyte.

The corrected analyte concentration is calculated as follows: 
Corrected Analyte Concn (ppb)=
Measured Analyte Concn (ppb) - (Interferent Concn (ppm) * IEC Factor)
  1. A dash indicates that no interference was observed on the analyte from the interfering analyte. Interfering analytes were analyzed at the following concentration:
200 ppm: Fe
100 ppm: Cr, Cu, Co, Mo, Ni
50 ppm: Mn, V, Ti
  1. IEC factors are instrument dependent. Interferences listed in this table do not represent all possible interferences.

1.7 Solubility and Stability of Lead Sulfate

The solubility of lead sulfate was investigated by weighing out various amounts and placing it in a conical beaker, along with a Ghost Wipe, and digested. The samples were reanalyzed four days later to determine if any lead had precipitated out of solution. Results were not blank corrected.

 
Table 1.7.1
Lead Sulfate Solubility and Stability

    day 1 day 4
PbSO4used (mg) theoretical for lead* (µg) lead found (µg) recovery (%) lead found (µg) recovery (%)

0.025 16.73 15.92 95.2 16.82 100.5
0.078 52.23 49.82 95.4 50.30 96.3
0.162 108.5 105.9 97.6 107.8 99.3
0.230 154.0 153.2 99.5 155.2 100.7
0.252 168.7 162.7 96.4 167.0 98.9
0.477 319.4 313.7 98.2 319.8 100.1
0.595 398.4 395.9 99.4 402.7 101.1
0.698 467.4 472.6 101.1 472.6 101.1
0.821 549.7 544.1 99.0 555.7 101.1
1.125 753.3 739.1 98.1 751.2 99.7
1.254 839.6 826.1 98.4 838.7 99.9
1.715 1148 1121 97.6 1144 99.6
2.025 1356 1326 97.8 1346 99.3
2.738 1833 1821 99.3 1845 100.6
4.584 3069 2993 97.5 3048 99.3


*Purity of lead sulfate used was 98%

1.8 Analysis of three NIST Standard Reference Materials

Approximately 100 mg of material was placed in a conical beaker along a Ghost Wipe. Samples were digested and then filtered through an MCE filter to remove all particulate. The MCE filter for each sample, along with the remaining particulate, were digested a second time. Results were not blank corrected.
 
Table 1.8.1
Standard Reference Material 2580 Lead Paint
element sample 1
weight = 101.6 mg
sample 2
weight = 100.9 mg
sample 3
weight = 100.6 mg
first digest (µg) second digest (µg) theor (µg) recovery (%) first digest (µg) second digest (µg) theor (µg) recovery (%) first digest (µg) second digest (µg) theor (µg) recovery (%)
Pb 2466 1653 4409 93.4 2345 992.0 4379 76.2 1730 1674 4366 78.0
Fe* 533.5 27.08 508.0 110 520.0 17.50 504.0 107 513.0 24.42 503.0 107
Zn* 2842 127.1 3048 97.4 2790 83.95 3027 94.9 2750 114.2 3018 94.9


*Results not certified by NIST


Table 1.8.2
Standard Reference Material 2583 Trace Elements in Indoor Dust
element sample 1
weight = 103.8 mg
sample 2
weight = 100.3 mg
sample 3
weight = 100.4 mg
first digest (µg) second digest (µg) theor (µg) recovery (%) first digest (µg) second digest (µg) theor (µg) recovery (%) first digest (µg) second digest (µg) theor (µg) recovery (%)
Cd 0.565 0.000 0.757 74.6 0.695 0.000 0.732 94.9 0.465 0.000 0.733 63.4
Cr 5.215 0.900 8.304 73.6 5.585 0.905 8.024 80.8 5.395 0.755 8.032 76.6
Pb 6.820 0.365 8.916 80.6 6.425 0.050 8.616 75.2 6.710 0.160 8.624 79.7


  
Table 1.8.3
Standard Reference Material 1648 Urban Particulate Matter
element sample 1
weight = 101.4 mg
sample 2
weight = 101.7 mg
sample 3
weight = 101.1 mg
first digest (µg) second digest (µg) theor (µg) recovery (%) first digest (µg) second digest (µg) theor (µg) recovery (%) first digest (µg) second digest (µg) theor (µg) recovery (%)
Pb 608.0 30.88 664.2 96.2 618.0 33.12 666.1 97.8 595.0 30.35 662.2 94.4
Cd 7.185 0.255 7.605 97.8 7.215 0.280 7.628 98.3 7.185 0.270 7.583 98.3
Cr 10.38 3.990 40.86 35.2 9.595 2.920 40.99 30.5 10.76 3.185 40.74 34.2
Cu 53.95 2.925 61.75 92.1 54.70 3.020 61.94 93.2 53.50 2.645 61.57 91.2
Mn 71.80 4.101 79.70 95.2 73.63 4.495 79.93 97.7 71.44 3.766 79.46 94.6
Ni 6.600 0.490 8.315 85.3 6.660 0.500 8.339 95.9 6.760 0.530 8.290 87.9
V 9.805 0.990 12.88 83.8 9.725 1.070 12.92 83.6 9.680 0.900 12.84 82.4


1.9 Instrument Analytical Conditions
Instrument: Perkin-Elmer Optima 4300 DV ICP
Replicates: 2
Read Time: Auto, 5-20 sec
Sample Flow Rate: 2.20 mL/min
Gas: Argon
Plasma Gas Flow: 15 L/min
Auxiliary Gas Flow: 0.20 L/min
Nebulizer Gas Flow: 0.60 L/min
RF Power: 1300 watts
Plasma View: Radial
View Distant: 15.0 mm
Peak Algorithm: Peak Area
Overlap Correction: IEC
Background Correction: 2-Point
Calibration: 2-Point


1 Lawrence, R. Evaluation Guidelines for Surface Sampling Methods ; OSHA Salt Lake Technical Center, U.S. Department of Labor: Salt Lake City, UT, 2001.

2 The Perkin-Elmer Corporation. WinLab32 Instrument Control Software Guide ; Norwalk, Ct, 1999.
 
 
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