Document ZJdN1zNq5QVemmb6Bap4QE540

Standard Method of Teat for LOW CONCENTRATIONS OP LEAD IN PAINT BY ATOMIC ABSORPTION SPECTROSCOPY ASTM D3335 - 74 1. Scope 1.1 This method covers the determination of lead contents between 0.01 and present in the solids of liquid coatings or contained in dry films. 1.2 Only pigmented coatings were used for evaluating this method, but there is no reason to believe that varnishes and lacquers could not be analyzed successfully, provided that appropriate precautions are taken. 2. Applicable Documents 2.1 ASTM Standards: D 1193 Specification for Reagent Water D 2832 Recommended Practices for Determining Nonvolatile Content of Paint and Paint Materials 3. Summary of Method 3.1 The sample of liquid paint or dried film is prepared for an alysis by dry ashing. The lead content of an acid extract of the ash is determined by atomic absorption spectroscopy. 4 Apparatus 14.. 1 Atomic Absorption Spectrophotometer, consisting of an atom izer and either a single or three-slot burner; gas pressure regulating and metering devices for air and acetylene; a lead hollow cathode tube with a regulated constant current supply; a monochromator and associated optics; a photosensitive detector connected to an electronic amplifier; and a red-out device. 14..2 Muffle Furnace, capable of maintaining 500 + 5^ C. 43 Crucibles, wide form, porcelain, glazed insTde and out except for the outside bottom surface, approximately 30-ml capacity, 50-rom rim diameter, and a 31-mm height. 44 Hot Plate, with variable surface temperature control over the range from 70 to 200 C. 4.5 High-Silica Glass Beakers, 100 and 250~ml 1+.6 Volumetric Flasks, 50, 100, and 1000 ml. 47 Dropping Bottles, | or | oz. capacity 4.8 Glass or Disposable Syringes, 5 or 10-ml capacity 4.9. Pipets, 1, 2, 5, and 10-ml capacity/ 5. Reagents 5.1 Purity of Reagents - Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, It is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such speci fications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination. 0007-PTL-000830 5.2 Purity of Water - Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to ASTM Specifications D1193* 5.3 Ammonium Acetate Diluting Solution - Add 50 ml of HNO, (sp. gr. 1.42) to 150 ml of 50$ weight by volume ammonium acetate solution and dilute to 1 litre. 5.4 Ammonium Acetate Solution (50# weight by volume) - Dissolve 500 g of ammonium acetate (NHhCpH^Op) in water and dilute to 1 litre. 5.5 Lead Standard Solution (1000 ppm.) - Dissolve 1.5980 g of lead nitrate (Pb(NO-i)p) in 10 ml of water, add 10 ml of HNO-a (sp. gr. l.ij.2) and dilute to 1 litre. ^ 5.6 Nitric Acid (sp. gr. 1.42) Concentrated Nitric Acid (HNO?) 5.7 Nitric Acid (1+1) - Add 1 volume of HNO^ to 1 volume water. 6. Calibration and Standardization 6.1 Prepare 100ml quantities of at least four standard solutions bracketing the expected lead concentration in the sample to be tested. To suitable aliquots of the 1000-ppm standard lead solution, add $ml of the HNO3 and 15 ml of the 50# ammonium acetate solution. Dilute to 100 ml with water. 6.2 Operational instructions for atomic absorption spectropho tometers vary with different models. Consult the manufacturer's literature for establishing optimum conditions for the specific instruement used. 6.3 Turn the instruement on and set the wavelength to the 2833A line for lead. Apply the current recommended by the manufacturer to the hollow cathode lamp. Allow the instruement to warm-up at least 15 minutes and set the slit width. Adjust the air pressures and ig nite the burner according to the manufacturer's instructions. 6.4 Aspirate water to rinse the atomizer chamber. Aspirate a standard solution and make any necessary readjustment in instruement parameters to obtain maximum absorption. f 6.5 Atomize each of the appropriate standard solutions and record the corresponding instruement readings. Atomize water between each standard. 6.6 Construct a calibration curve on linear graph paper by plot ting the absorbance versus concentration (micrograms/millilitre) fof each standard solution on linear graph paper. 7. Proceedure 7.1 If the sample is a liquid coating, mix it until homogeneous, preferably on a mechanical shaker. Determine the nonvolatile content in accordance with Method D 2832. / 7.2 Prepare at least two replicate samples by weighing by dif ference from a dropping bottle or syringe approximately 2 to 3 g of the mixed paint, or by directly weighing approximately 1 to 2 g of dried paint film, into a 30 ml porcelain crucible. Weigh to the nearest 0.1 mg. See Note 1, and 2. 7.3 Place the crucible (or beaker) containing the liauid coating on a hot plate and slowly increase the temperature until the material ^ried. With some types of coatings, an initial oven-drying at 105 C may be necessary to remove solvents without incurring losses due to spattering. 0007-PTL-000831 7.4 When the specimen appears to be dry or when starting with a dry film, gradually increase the temperature of the hot plate until the specimen chars. 7.5 After charring is complete, place the material in a preheated muffle furnace and ash at 475 to 500 C. See Note 3 7.6 When the ashing appears to be complete (approximately 1 to 2 h), remove the crucible or beaker from the muffle furnace and allow it to cool to room temperature. Break up the ash into fine particles with a glass stirring rod, leaving the rod with the container through the filtering step. 7.7 Add 10 ml of HNO^ (1+1) acid, taking care to avoid losses due to spattering in case^the ash reacts violently with the acid. Heat carefully on hot plate until 2 to 3 ml of the solution remain. Add an additional 10 ml of HNO-j (1+1) acid and continue heating on the hot plate until less than 5 nil of the solution remains, 7.8 Filter the solution through medium porosity filter paper into a 50-ml volumetric flask. If the filtrate is not clear, refilter through fine porosity filter paper. Wash the container 3 times with 2.5 ml hot ammonium acetate solution (5*4)# each time transferring the washings to the filter paper. Wash the filter paper several times with water. Adjust the volume to 50-ml with water. 7.9 Aspirate the specimen solution and determine the absorbance in the same manner in which the instruement was calibrated. Determine the concentration of lead in micrograms/ millilitre from the cali bration curve. If the absorbance is above the range covered by the calibration curve, dilute an aliquot cf the sample solution to a suitable volume with ammonium acetate diluting solution. See Note 4* 8. Calculation 8.1 Calculate lead in the nonvolatile portion of the sample as follows: Lead, % of nonvolatile = (C x F x 0.5)/(NV x S) f where: C = micrograms per millilitre concentration of lead in the aspir ated sample solution. F = dilution factor from 7*9 (Volume diluted to/volume of aliquot) NV = percent nonvolatile of paint sample (use 100 if sample was a dried film), and S = grams of specimen 9. Report 9.1 Report the percent lead of the nonvolatile content of the paint and whether the analysis was done on a liouid samole or dried film. 10. Precision 10.1 The following criteria should be used for accepting the results. 10.1.1 Repeatability (Single Analyst) - The coefficient of varia tion of results (each the average of duplicate determinations) obtained by the same analyst on different days was estimated to be 3*4$ relative 24 degrees freedom. Two such values should be considered susoect (95% confidence level) if they differ by more than 10# relative.' 0007-PTL-000832 10.1.2 Reproducibility (Multilaboratory) - The coefficient of variation of results (each the average of duplicate determinations) obtained by analysts in different laboratories, has been estimated to he 9.3J& relative at 20 degrees of freedom. To such values should be considered suspect (9$% confidence level) if they differ by more than 27% relative. f 0007-PTL-000833 NOTES 1. The specimen size specified will give a concentration of approx imately 10 to 20 ppm lead in the final diluted solutions for materials containing approximately 500 ppm lead based on the solids. If the sample is estimated to contain more or less than 500 ppm lead, the specimen size should be adjusted accordingly. In the event that significantly less than 500 ppm lead is expected, a 250-ml high-silica glass beaker may be used instead of the cru cible accomadating sample weights up to 10 g. 2. Recover dried paint films from previously coated substrates or prepare in the laboratory from liquid samples. For the labor atory preparation, flow the well-mixed sample onto a clean glass plate and allow to dry in an oven at 105 C. Scrape the dried film off the glass plate with a single-edge razor blade. 3. Ashing at temperatures in excess of 500 C. may result In the loss of some of the lead by volitization. k-. The method of standard additions may be used to improve the accur acy of the analysis. This method is particularly recommended for use with unknown samples, where matrix effects may be poten tially significant. For a detailed description of the proceedure and calculations used in the method of standard additions, consult a standard text on atomic absorption spectroscopy or the instruement manual provided by the instruement manufacturer. 0007-PTL-000834 l Designation: D 3335 - 78': sy? An American National Standard Standard Test Method for LOW CONCENTRATIONS OF LEAD, CADMIUM, AND COBALT IN PAINT BY ATOMIC ABSORPTION SPECTROSCOPY1 * This standard is issued under the fixed designation D 3335; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year oflast revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. No t e 1--An editorial change was made by adding Section 1.4 in December 1978. "Non: 2--An editorial change was made in Section 9.1 in June 1980. 1. Scope D2832 Recommended Practices for Deter 1.1 This method covers the determination of |. lead" contents between 0.01 and 5 %, cadmium mining Nonvolatile Content of Paint and Paint Materials4 j contents between 50 and 150 ppm (mg/kg), and cobalt contents between 50 and 2000 ppm ; ; (mg/kg) present in the nonvolatile portion of j` liquid coatings or contained in dried films. !: There is no reason to believe that higher levels of all three elements could riot be determined by this method, provided that appropriate di 3. Summary of Method 3.1 The specimen of liquid coating or dried film is prepared for analysis by dry ashing. The content of lead, cadmium, or cobalt of an acid extract of the ash is determined by atomic absorption spectroscopy. lutions and adjustments in specimen size and reagent quantities are made. 4. Apparatus 4.1 Atomic Absorption Spectrophotometer, No t e 1--ASTM Method D 2088, Determination consisting of an atomizer and either a single-- j of Low Concentrations; of Lead in Paint,3 describes I an alternative method of analysis for lead, using an or three-slot burner: gas pressure regulating j electrolytic analyzer. and metering devices for air and acetylene; 1.2 Only pigmented coatings were used for evaluating this method, but there is no reason to believe that varnishes and lacquers could not be analyzed successfully, provided that appro priate precautions are taken. 1.3 This method is not applicable to the determination of lead in samples containing antimony pigments (low recoveries are ob lead, cadmium, and cobalt source lamps5 with a regulated constant-current supply; a mono chromator and associated optics; a photosensi tive detector connected to an electronic ampli fier; and a read-out device. 4.2 Muffle Furnace, capable of maintaining 500 10C. 4.3 Crucibles, wide-form, porcelain, glazed tained). 1.4 If lead is present in the Sample to be analyzed in the form of an organic lead com pound at a concentration greater Than-0.1 %, small losses of lead may occur, resulting in slightly poorer precision than shown in Section 11. 2. Applicable Documents 2.1 ASTM Standards: D 1193 Specification for Reagent Water5 1 This method is under the jurisdiction of ASTM Com mittee D-l on Paint and Related Coatings and Materials and is the direct responsibilityof Subcommittee DO 1.21 on Chem ical Analysis of Paints and Paint Material. Current edition approved Nov. 9. 1978. Published January 1979. Originally published as D 3335 - 74. Last previous edition D 3335 - 77. 1 Vandeberg, J. T.. Swafford. H. D.. and Scott. R. W.. "Determination of Low Concentrations of Lead in Paint" Journals of Paint Technology. JPTYA, Vol 47, No. 604, May 1975. 3 1983 Annual Book of ASTM Standards. Vol 06.03. * 1983 Annual Book of ASTM Standards. Vol 06.01. 5 Both hollow cathode lamps and electrodeless discharge lamps have been found satisfactory for this purpose. -vr S' W'\ D 3335 inside and outside except for the outside bottom surface, approximately 30-ml capacity. 50-mm rim diameter and 31 mm height.6 4.4 Hot Plate, with variable surface temper ature control over the range from 70 to 200C. 4.5 High-Silica Glass Beakers/ 100 and 250ml. 4.6 Volumetric Flasks, 50, 100, and 1000-ml. 4.7 Dropping Bottles, V> or Vi-oz (7 or 15-ml) capacity. 4.8 Glass or Disposable Springes, 5 or 10-ml capacity. 4.9 Pipets, 1, 2, 5, and 10-ml capacity. 4.10 Paint Shaker. 4.11 Paint Draw-Down Bar. 5. Reagents 5.1 Purity of Reagents--Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all re agents shall conform to the specifications of the Committee on Analytical Reagents of the' American Chemical Society, where such spec ifications are available.8 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of .the determination. .L-V-"' 5.2 Purity of Water--Unless otherwise indi cated, references to water shall be understood to mean Type 11 reagent grade water conform ing to Specification D 1193. 5.3 Ammonium Acetate Solution (50% weight/volume)--Dissolve 500 g of ammonium acetate (NH4C2H3O2) in water and dilute to 1 litre. 5.4 Ammonium Acetate Diluting Solution-- Add 50 ml of HN03 (sp gr 1.42) to 150 ml of 50 %. weight/volume ammonium acetate solu tion and dilute to 1 litre. 5.5 Cadmium Standard Stock Solution (1000 fig/ml)--Dissolve 2.1032 g of cadmium nitrate (Cd(N03)2) in 10 ml of water, add 10 ml of HNO3 (sp gr 1.42); and dilute to 1 litre. 5.6 Cobalt Standard -Stock Solution (1000 pg/ml)--Dissolve 4.9387 g of cobalt nitrate hexahydrate (Co(N03)2-6H20) in 10 ml of wa ter, add 10 ml of HN03:(sp gr 1.42), and dilute to 1 litre. 5.7 Lead Standard Stock Solution (1000 pg/ml)--Dissolve 1.5980 g of lead nitrate (Pb(N03)2) in 10 ml of water, add 10, ml of HNO:) (sp gr 1.42), and dilute to 1 litre. I 5.8 Nitric Acid (sp gr 1.42)--Concentrated nitric acid (HNO3). 5.9 Nitric Acid (1+1)--Add 1 volume of HNO3 (sp gr 1.42) to 1 volume of water. 6. Safety Precautions 6.1 Concentrated nitric acid is corrosive and may cause severe burns of the skin or eyes: the vapor is irritating to mucous membranes. Use care in handling this acidic substance. In case of contact, flush skin or eyes with plenty of water, while removing contaminated clothing and shoes. Call a physician. Wash clothing before reuse. See MCA Chemical Safety Data Sheet SD-5. ' : 6:2 Use only a rubber bulb aspirator for pipeting liquids. 7. Calibration and Standardization 7.1 Prepare 100-ml quantities of at least four standard solutions bracketing the expected lead, cadmium, or cobalt concentration in the sample to be tested. To suitable aliquots of the 1000 pg/ml standard lead, cadmium-, or cobalt solution, add 5 ml of HNQ3 (spgr 1.42) and 15 ml Of 50 % ammonium acetate solution. Dilute to 100 ml with water. 7.2 Operational instructions for atomic ab sorption spectrophotometers vary with differ ent models. Consult .the manufacturer's litera ture for establishing optimum conditions for the specific instrument used. - 7.3 Turn the instrument on and set the wave length to the 283.3.mm lead line, the 228.8-nm Cadmium line, or the' 240.7-nm cobalt line. Apply the current recommended by the man ufacturer to the lead, cadmium, or cobalt source lamp. Allow the instrument to warm up for about 15 min and set ..the slit width. Adjust the air and acetylene pressure or flow rates and ignite the burner in accordance with the man ufacturer's instructions. 7.4 Aspirate.:.water to rinse the atomizer * Coors No. 25007crucibles, or equivalent, have been found satisfactory for this purpose, c ' 7 Vycor beakers tnanufacuired by the Coming Glass Co. i have been found, satisfactory for this purpose. i * "Reagent.Chemicals: American Chemical Society Specify- - cations,'* Arm Chemical Soc.,'Washington. D. C. For sugges- t lions on the testingTbf reagents not listed by the American Chemical Society. see^Reagent Chemicals and Standards." by $ Joseph Rosin. D. Van Nostrand Co., Inc.. New York. N. Y- * and the "United States'Pharmacopeia " V \ i 656 0007-PTL-000836 Massk--sfft-*. ? chamber. Aspirate a standard solution and make any-necessary readjustment in instrument parameters to obtain maximum absorption. 7.5 Aspirate each of the appropriate-stan dard solutions and record the corresponding instrument readings. Aspirate water between each standard. 7.6 Construct a calibration curve on linear graph paper by plotting the absorbance versus remove solvents without incurring losses due to spattering. 8.4 When the specimen appears to be dry or when starting with a dried film, gradually in crease the temperature of the hot plate until the material chars. 8.5 After charring is complete, place the con. tainer in a preheated muffle furnace and ash at 475 to 500C. concentration, (micrograms per milliire) for each standard solution. '- No t e 4--Ashing at temperatures in excess of 500C may result in the loss of some lead by volatil ization. 8. Procedure 8.6 When the ashing appears to be complete 8.1 If the sample is a liquid coating; mix it (do not exceed 1 to 2 h), remove the crucible or until homogeneous, preferably on a mechanical . beaker from the muffle furnace and allow it to shaker. Determine the nonvolatile content in cool to room temperature. Break up the ash accordance with Method D 2832. into fine particles with a glass stirring rod, 8.2 Prepare at least two replicate" specimens- leaving the rod with the container through the by weighing by difference from a dropping filtering step. bottle or syringe approximately 2 to 3 g of the 8.7 Add 10 ml of HNOi (14-1). taking care mixed liquid coating, or by directly weighing to avoid losses due to spattering in case the ash approximately-1 to.2:g ofdried paint film, into " reacts vigorously with the acid. Heat carefully a 30-ml porcelain crucible. Weigh.to the nearest on a hot plate until 2 to 3 ml of solution remain. Oil mg. Add an additionaT 10 ml of HNO.i (l + l)~and No t e 2--The.specimen size calledfor will give a continue heating on the hot plate until less than concentration of approximately 10 tcr20 pg/m! lead 5 ml of the solution remains. * in the final diluted solution for paints^containing approximately :5O0 ppm (mg/kg) lead, ba'sed: on the- 8.8 Filter the solution through medium-po sohds. If the material is estimated to contain more or rosity filter paper into a 50-ml volumetric flask. less than 500 ppm (mg/kg) lead;-:the quantity taken -- If the filtrate is not clear, refilter through fine- should be adjusted accordingly. In the event that porosity filter paper. Wash the container three significantly less than 500 ppm (mg/kg) lead is ex pected, a 250-mi high-silica beaker may be used in -times with 2.5 ml of hot arnmonium acetate place of the'crucible to accommodate specimen smutjop (5.3), each time transferring the wash- weights up to 10-gV'Thd size Specified will give a- -ings to the filter paper. Wash the filter-paper concentration of'approximately 2 to 4 ng/ml cad mium in.ihe ftnal.dtluted solution for paints contain several times with water. Adjust the volume to ing approximately lOOpprii (mg/kg) cadmium, based 50 ml with water and mix. on the solids. The size specified will give a concen 8.9 Aspirate the test solution and determine tration ofapproximately 10.to 20 gg/ml cobalt in the final diluted solution Tor paints containing approxi-- . the absorbance in the same manner in which mately 500 ppm (mg/kg) cobalt, based on the solids. the instrument was calibrated. Determine the No t e 3--Recover dried paint films from previ concentration of lead, cadmium, or cobalt in ously coated substrates (being careful not to remove any underlying material from the substrate), or pre- {iare in the laboratory from liquid samples. For the aboratory preparation, flow some of the well-mixed micrograms per millilitre from the calibration curve. If the absorbance is above the range covered by the calibration curve, dilute an ali sample onto a clean glass" plate. The use of a paint quot of the sample solution to a suitable volume draw-down bar is recommended to.obtiliri a uniform wet film thickness not exceeding 2 mils (50 pm). with ammonium acetate diluting solution. Allow the film to dry in an oven at 105C for a No t e 5--For maximum accuracy, calibration and minimum of l h. .Scrape the dried film off the glass standardization (Section 6) should be completed just plate, preferably with a single-edge razor blade. prior to aspirating the sample solution. 8.3 Place the crucible (or beaker) containing No t e 6--The method of standard additions may be used to improve the accuracy of the analysis. This the liquid coating on a hot plate and slowly method is particularly recommended for use with increase the temperature until the material is dried. With some types of coatings, an initial unknown samples where matrix effects may be po tentially significant. For a detailed description of the procedure and calculations used in the method of oven-drying at l.05.C may be necessary to standard additions, consult a standard text on atomic 41b D 3335 absorption spectroscopy or the instruction manual relative at 21 degrees of freedom for cobalt. provided bv the instrument manufacturer. The between-laboratofy coefficient.Of variation 9. Calculation 9.1 Calculate the mean concentration of lead, cadmium, or cobalt in the nonvolatile portion of the sample as follows: was 9.3 c7c relative at 20 degrees of freedom for lead, 8.9 % relative at 11 degrees of freedom for cadmium, and 5.5 ft relative at'17 degrees of freedom for cobalt. Based on these coefficients, the following criteria should be used for judg lead, cadmium or cobalt. pDm (ma/kg) in nonvolatile ing the'acceptability of results at the 95 % con = (Cx/x 5000)/(A'V x S) fidence level:' 11.1.1 Repeatability-- Two results, each the = concentration oflead, cadmium, or co mean of duplicate determinations, obtained by balt in the aspirated specimen solution, the same operator on different days should be (Mg/ considered suspect if they differ by more than = dilution factor from 8.9 (volume di-. 11 % relative for all three metals. luted to/volume of aliquot), 11.1.2'.Reproducibility--Two, results, each 5000 = factor derived from multiplying the 50 ! the mean of duplicate determinations, obtained v mL volume obtained in Par. 8.8 by 100 by operators in different laboratories should be (to convert NV used to a whole num- considered suspect if they differ by more than yfiber) and 106 (to obtain PPM), then 28 % relative'Tor lead or cadmium and if they dividing by 10s (to convert grams of differ by more than 17 % relative for cobalt. sample to pg). 11.2 Accuracy: = percent nonvolatile of paint sample 11.2.1 The. true value for the amount oflead (use 100 if sample was a dried film), present in the solids of a coating should be and = grams of sample. between 97 and 111 %. of the experimental value. ' . _ '.-. 10. Report 11.2.2 The true value for the amount of cad mium present in the solids of a coating should 10.1 Report the lead, cadmium, or cobalt be between'77 and 143 of the experimental content of the nonvolatile content of the sample value. . and whether the analysis w>as conducted on a. . 11.2:3 The true value for the amount of co liquid coating or a dried film. balt present in the solids of a coating should be 11. Precision and Accuracy9 between 96 and 120 % of the experimental value. . 11.1 In an interlaboratory study of the method the within-Iaboratory coefficient /of variation was found to be 3.4 % relative at 24 degrees of freedom for lead, 3.7 % relative'at 15 degrees of freedom for cadmium, and 3.31 9 Results of the'imeriaboraiory studies of this method, which were used to. dalculaxe precision, are available from ASTM. 1916 Race' St.;.'Philadelphia. Pa;' 19!'03^as RR: D01-1005. 77ie American Societyfor Testing and Materials takes no position respecting the validity of: arty patent rights asserted in connection with any item mentioned in this standard. Users of.this standard are expressly advised that.determination ofthe validity of any such patent rights, and the risk of infringement of such rights, are entirety tpeir own responsibility.' This standard is subject to revision at any time by the responsible technical committee and must: be reviewed everyfiveyears and if not revised, either reapproved or withdrawn. Your comments-are invited eitherfor revision oflhis standard orfor additional standards and should be addressed to A STM Headquarters. Your comments will receive careful consideration at a meeting ofthe responsible technical committee, which y o u may attend. Ifyoufeel thatyour corhrnerits have not received afair hearingyou should make your views known to the A STM Committee on Standards, 1916 Race St:, Philadelphia, Pa. 191.03. ' 0007-PTL-000838 H A nT IN C O . M IN N , - LO G A N . OHIO U .9.A