ASTM E2330-2012 Standard Test Method for Determination of Concentrations of Elements in Glass Samples Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for Forensic Compa.pdf

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1、Designation:E233004 Designation: E2330 12Standard Test Method forDetermination of Trace Concentrations of Elements in GlassSamples Using Inductively Coupled Plasma MassSpectrometry (ICP-MS) for Forensic Comparisons1This standard is issued under the fixed designation E2330; the number immediately fol

2、lowing the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test metho

3、d covers a procedure for elemental analysis of magnesium (Mg), aluminum (Al, titanium (Ti), manganese(Mn), gallium (Ga), rubidium (Rb), strontium (Sr), zirconium (Zr), antimony (Sb), barium (Ba), lanthanum (La), cerium (Ce),samarium (Sm), hafnium (Hf) and lead (Pb) in the bulk of glass samples (irre

4、gularly shaped and as small as 200 micrograms) forthe comparison of fragments of a known source to the recovered fragments from a questioned source. These elements are presentin soda lime and borosilicate glass in ngg-1to % levels. Alternative methods for the determination of elemental analysis of g

5、lassare listed in the references. This procedure may also be applicable to other elements, other types of glass, or other concentrationranges with appropriate modifications of the digestion procedure (if needed for full recovery of the additional elements) and themass spectrometer conditions. The ad

6、dition of calcium and potassium, for example, could be added to the list of analytes in amodified analysis scheme.1.2One objective of a forensic glass examination is to compare glass samples to determine if they can be discriminated usingtheir physical, optical or chemical properties (for example, c

7、olor, refractive index (RI), density, elemental composition). If thesamples are distinguishable in any of these observed and measured properties, it may be concluded that they did not originate fromthe same source of broken glass. If the samples are indistinguishable in all of these observed and mea

8、sured properties, thepossibility that they originated from the same source of glass cannot be eliminated. The use of an elemental analysis method suchas inductively coupled plasma mass spectrometry yields high discrimination among sources of glass.1.2 This test method covers a procedure for quantita

9、tive determination of the concentrations of magnesium (Mg), aluminum(Al), iron (Fe), titanium (Ti), manganese (Mn), rubidium (Rb), strontium (Sr), zirconium (Zr), barium (Ba), lanthanum (La), cerium(Ce), neodymium (Nd), samarium (Sm), and lead (Pb) in glass samples.1.3 This procedure is applicable t

10、o irregularly shaped samples as small as 200 micrograms, for the comparison of fragments ofa known source to the recovered fragments from a questioned source. These elements are present in soda lime and borosilicateglass in ppb to % levels1.4 This procedure is applicable to other elements, other typ

11、es of glass, and other concentration ranges with appropriatemodifications of the digestion procedure (if needed for full recovery of the additional elements), calibration standards and the massspectrometer conditions. Calcium and potassium, for example, could be added to the list of analytes in a mo

12、dified analysis scheme.Alternative methods for the determination of concentrations of elements in glass are listed in the references.1.5 For any given glass, approximately 40 elements are likely to be present at detectable concentrations using this procedurewith minor modifications. The element set

13、stated here is an example of some of these elements that can be detected in glass andused for forensic comparisons.1.6 This guide cannot replace knowledge, skill, or ability acquired through appropriate education, training, and experience andshould be used in conjunction with sound professional judg

14、ment.1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establ

15、ish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1This test method is under the jurisdiction of ASTM Committee E30 on Forensic Sciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.Current edition approved

16、Aug. 1, 2004. Published August 2004. DOI: 10.1520/E2330-04.Current edition approved June 15, 2012. Published July 2012. Originally approved in 2004. Last previous edition approved in 2004 as E2330 04. DOI: 10.1520/E2330-12.1This document is not an ASTM standard and is intended only to provide the us

17、er of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard a

18、s published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2. Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods3. Summ

19、ary of Test Method2.1The3.1 The glass fragments are digested using a mixture of hydrofluoric, nitric and hydrochloric acids. Following aciddigestion, the samples are taken to dryness to eliminate most of the silicate matrix and the excess acids. Then an internal standardrhodium (Rh) is added as the

20、samples are reconstituted in nitric acid. Dilutions may be utilized to quantitate those elements thatare present in higher concentrations.2.2An3.2 An inductively coupled plasma mass spectrometer is used to measure the concentrations of the identified elements(1.1). The instrument should be adjusted

21、for maximum sensitivity, best precision and to minimize oxides and doubly charged ioninterferences. The instrument is then calibrated per manufacturer recommendations, using multi-elemental calibration standardswith the same internal standards (Rh and Sc) as that those added to the samples.23.3 Reag

22、ent blanks are measured along with the samples because detection limits are usually limited by the background signalsgenerated by the reagent blanks. The limits of detection of the method are expected to be between 0.5 ngg-1ppb and 25 ngg-1ppbin solution for most elements.3.4. Significance and Use3.

23、1This4.1 This technique is destructive, in that the glass fragments may need to be crushed, and must be digested in acid.34.2 Although the concentration ranges of the calibration curves shown in Appendix X1 are applicable to soda lime andborosilicate glass, this method is useful for the accurate mea

24、surement of trace elements from a wide variety of glass samples.3.3The determination the elemental concentrations in glass allows for additional data that can be compared between fragments.A standardized, validated method can aid in the interchange of data between laboratories.3.4It should be recogn

25、ized that the method measures the bulk concentration of the target elements. Any extraneous materialpresent on the glass that is not removed before digestion may result in a measurably different concentration of the elements.3.5The precision and accuracy of the method should be established in each l

26、aboratory that employs the method. Confidenceintervals or a similar statistical quality statement should be quoted along with any reported concentration value.4.are applicable to soda lime and borosilicate glass, this method is useful for the accurate measurement of elementconcentrations from a wide

27、 variety of glass samples.4.3 The determination of the element concentrations in glass yields data that can be used to compare fragments.4.4 It should be recognized that the method measures the bulk concentration of the target elements. Any extraneous materialpresent on the glass that is not removed

28、 before digestion may result in inaccurate concentrations of the measured elements.4.5 The precision and accuracy of the method should be established in each laboratory that employs the method.5. Apparatus4.15.1 ICP-MSAn ICP-MS instrument is employed. Since there are many manufacturers, the specific

29、ation of the instrumentshould be noted within the analysis results.4.2The instrument should be tuned prior to the analysis using the manufacturers recommendations covering the mass range ofthe identified elements. The instrument should be adjusted for maximum sensitivity, best precision and to minim

30、ize oxides anddoubly charged ion interferences. The instrument is then calibrated per manufacture recommendations using multi-elementalcalibration standards with the same internal standard as that added to the samples.4.3ReplicatesThe minimum number of measurement replicates per sample should be thr

31、ee with consideration for additionalmeasurements, if practicable4.4An ICP-MS instrument is employed.5.2 Standard Reference GlassesA minimum of two different reference glasses of known elemental composition should beused.5.Calibration5.1Two calibration curves as well as two check standards are used (

32、Appendix X1). The calibration standards must be NISTtraceable.5.2For the trace element standards calibration curve, Rh (50 ngg-1) is used as an internal standard and the elements are groupedaccording to the expected concentrations. The first group consists of Mg, Ti, Mn, Sr, Zr, Sb, Ba and Pb with a

33、 concentration rangeof 0 to 150 ngg-1. The second group consists of Ga, Rb, La, Ce, Sm and Hf with a concentration range of 0 to 50 ngg-1ppb.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvol

34、ume information, refer to the standards Document Summary page on the ASTM website.E2330 1225.3The check standard for the calibration is 50 ngg-1for the first group and 5 ngg-1for the second group.5.4The high standards calibration curve has Sc (60 ngg-1) as an internal standard and is composed of thr

35、ee concentrations levelsof Mg, Al, and Ba from 0 to 150 ngg-1.5.5The check standard for the high standard calibration curve is 60 ngg-1in all elements including Sc.5.6The system calibration must be checked daily (or on the days the instrument is in use for analysis) and prior to theperformance of an

36、 analysis, as well as during the analysis after every ten samples. This is accomplished by the analysis of the checkstandards as a continuing calibration verification (CCV).5.7The system is recalibrated any time that the control falls outside the acceptable parameters established by the laboratory o

37、ranalyst for this procedure (10% tolerance is recommended). A minimum of two different standard reference glasses of knownelemental composition should be used. Examples suitable for this analysis include NIST 1831 and NIST 612 Reference Glasses.5.3 Non-Glass Laboratory Warefor digestion.5.4 Micro-Ba

38、lance, with a precision of 61 g or better.5.5 High Purity Reagents, ICP-MS grade acids and reagents for digestion and dilution.5.6 Laboratory Oven or Dry Bath Block, for digestion.5.7 Micropipettes, used for the addition of reagents.5.8 Method Detection Limit (MDL) and Limit of Quantitation (LOQ)The

39、 limits of detection of the method (MDL)aredetermined for each element by measuring the three procedure blanks on two non-consecutive days. Multiply by three the standarddeviation (three instrumental replicates) of the measured intensities calculated by the calibration curve for that element in the

40、daythat it is measured. To calculate the limits of quantitation for the method (LOQ), multiply by ten the standard deviation (threeinstrumental replicates) of the measured intensities calculated by the calibration curve for that element in the day that it ismeasured. The measured intensities must be

41、 converted to concentration units using the appropriate calibration curve and thestandard deviations calculated from the concentrations. To calculate these limits of detection and quantitation, the average fromthe results for the two days is taken.NOTE1Table X2.1 illustrates the values for MDL, LOQ

42、and expected values for a set of 50 soda-lime glass samples all expressed as ngg-1of theelemental concentration in the final solution Fume Hood, for work with acids and removal of HF fumes.6. Procedure6.1Prior to crushing the glass sample for the digestion, wash samples separately in MeOH for 10 min

43、 and rinse 3 times withhigh purity water (18 M-cm). Wash in 1.6 molL-1HNOSample Preparation6.1 The sample set for analysis will include all known samples, questioned samples and at least two standard reference glasses.Prior to crushing the glass sample for the digestion, soak samples in concentrated

44、 HNO3for 30 min, rinse 3 times with high puritywater and air-dry overnight.6.2The samples are crushed between clean polystyrene weighing boats using a pestle, taking care not to puncture the boats.6.3Approximately 2 to 3 mg of each sample should be accurately weighed (with a precision of 6 1g or bet

45、ter) andquantitatively transferred into a labeled polypropylene test tube with a cap. Each sample should be weighed in triplicate for threedetermination for each glass exhibit.with a precision of 6 1 g or better.6.4All volumes are delivered using pipetters. The following mixture is added to each sam

46、ple, and standards: 150 L ofconcentrated HNO, rinse 3 times with high purity water, and allow the samples to dry.6.2 The samples are crushed between clean polymeric materials, such as polystyrene weighing boats or glassine sheets, takingcare not to puncture the materials.6.3 Approximately 2 to 3 mg

47、of each sample should be accurately weighed using a microbalance (with a precision of 61gor better) and quantitatively transferred into a labeled non-glass tube with a cap. At least three weighings per glass source shouldbe made for a minimum of three analytical samples per glass source for digestio

48、n. Empty labeled non-glass tubes should beprepared for reagent blanks.6.4 All volumes are delivered using micropipettes. Add concentrated hydrofluoric acid, concentrated hydrochloric acid, andconcentrated nitric acid to each tube to make a 2:1:1 mixture of the acids in the tubes.6.5 The tubes are ca

49、pped, vortex mixed, and placed in an ultrasonic bath to assist in the digestion for approximately one hour.The tubes are then uncapped and placed in a dry bath block or an oven, at 80C or greater (but below the softening temperatureof the digestion tubes), and taken to dryness.6.6 The samples are reconstituted by adding 500 L of 50 % HNO3(16 molL(8.0 molL-1), 300 L of concentrated HF (29 molL-1),and 150 L of concentrated HCl (12 molL-1). This acid mixture is also used to prepare the reagent blanks.NOTE2All reagents are at least trace metal quality for ICP-MS.N