1、Designation: E2927 13E2927 16Standard Test Method forDetermination of Trace Elements in Soda-Lime GlassSamples Using Laser Ablation Inductively Coupled PlasmaMass Spectrometry for Forensic Comparisons1This standard is issued under the fixed designation E2927; the number immediately following the des
2、ignation 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.INTRODUCTIONOne objective of a forensic g
3、lass examination is to compare glass samples to determine if theycanmay be discriminated using their physical, optical or chemical properties (for example, color,refractive index (RI), density, elemental composition). If the samples are distinguishable in any ofthese observed and measured properties
4、, it may be concluded that they did not originate from the samesource of broken glass. If the samples are indistinguishable in all of these observed and measuredproperties, the possibility that they originated from the same source of glass cannot may not beeliminated. The use of an elemental analysi
5、s method such as laser ablation inductively coupled plasmamass spectrometry yields high discrimination among sources of glass.1. Scope1.1 This test method covers a procedure for the quantitative elemental analysis of the following seventeen elements: lithium(Li), magnesium (Mg), aluminum (Al), potas
6、sium (K), calcium (Ca), iron (Fe), titanium (Ti), manganese (Mn), rubidium (Rb),strontium (Sr), zirconium (Zr), barium (Ba), lanthanum (La), cerium (Ce), neodymium (Nd), hafnium (Hf) and lead (Pb) throughthe use of Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) for the foren
7、sic comparison of glassfragments.The potential of these elements to provide the best discrimination among different sources of soda-lime glasses has beenpublished elsewhere (1-5).2 Silicon (Si) is also monitored for use as an internala normalization standard. Additional elementscanmay be added as ne
8、eded, for example, tin (Sn) can be used to monitor the orientation of float glass fragments.1.2 The method only consumes approximately 0.4 to 2 gg of glass per replicate and is suitable for the analysis of full thicknesssamples as well as irregularly shaped fragments as small as 0.1 mm by 0.4 mm in
9、dimension. The concentrations of the elementslisted above range from the low parts per million (gg-1) to percent (%) levels in soda-lime-silicate glass, the most common typeencountered in forensic cases. This standard method may be applied for the quantitative analysis of other glass types; however,
10、some modifications in the reference standard glasses and the element menu may be required.1.3 This standard does not replace knowledge, skill, ability, experience, education or training and should be used in conjunctionwith professional judgment.1.4 The values stated in SI units are to be regarded a
11、s standard. No other units of measurement are included in this standard.1.5 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 establish appropriate safety and health practices and determine t
12、he applicability of regulatorylimitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedb
13、y the World Trade Organization Technical Barriers to Trade (TBT) Committee.1 This 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 June 1, 2013Dec. 1, 2016. Published Ju
14、ly 2013April 2017. Originally approved in 2013. Last previous edition approved in 2013 as E2927 13.DOI: 10.1520/E2927-13.10.1520/E2927-16.2 The boldface numbers in parentheses refer to a list of references at the end of this standard.This document is not an ASTM standard and is intended only to prov
15、ide the user 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
16、standard as 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 States12. Referenced Documents2.1 ASTM Standards:3E2330 Test Method for Determination of Concentrations of Elements in Gl
17、ass Samples Using Inductively Coupled Plasma MassSpectrometry (ICP-MS) for Forensic ComparisonsE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsC162 Terminology of Glass and Glass Products3. Terminology3.1 Definitions:3.1.1 calibration standard, nused to determine the quanti
18、tative analysis for the analyte elements of interest in the glass matrix.The calibration standard(s) shall have a known elemental composition including a known uncertainty for the reported analytes.3.1.2 glass, nan inorganic product of fusion that has been cooled to a rigid condition without crystal
19、lization. C1623.1.3 normalization standard, nan element that is present in the glass matrix at elevated and relatively homogeneousconcentration that may be used to normalize the laser ablation signal to compensate for any variation on the ablated mass orinstrumental drift.4. Summary of Test Method4.
20、1 The glass fragments usually do not require sample preparation prior to the LA-ICP-MS analysis. However, they may bewashed with solvents or pre-ablated if necessary.4.2 The glass fragment is placed inside an ablation chamber and a laser beam is focused on the surface of the sample. Whenthe ablation
21、 is started, the interaction between the pulsed laser and the sample surface produces a cloud of very small particles,which are transported from the ablation cell by a carrier gas into the ICP-MS for analysis.4.3 An ICP-MS is used to quantify the elements of interest.4.4 Quantitative analysis is acc
22、omplished using well-characterized glass standards whose major elemental composition issimilar to the material to be analyzed.4.5 A comparison between the reported elemental compositions of the known and recovered glass fragments may result in adecision on whether the samples are distinguishable by
23、elemental composition or indistinguishable by elemental composition.5. Significance and Use5.1 This test method is useful for the determination of elemental concentrations in the microgram per gram (gg-1) to percent(%) levels in soda-lime glass samples. A standard test method canmay aid in the inter
24、change of data between laboratories and inthe creation and use of glass databases.5.2 The determination of elemental concentrations in glass provides high discriminating value in the forensic comparison ofglass fragments.5.3 This test method produces minimal destruction of the sample. Microscopic cr
25、aters of 50 to 100 m in diameter by 80 to150-m deep are left in the glass fragment after analysis. The mass removed per replicate is approximately 0.4 to 3.1 g.5.4 Appropriate sampling techniques shouldshall be used to account for natural heterogeneity of the materials at a microscopicscale.5.5 The
26、precision, accuracy, and limits of detection of the method (for each element measured) shouldshall be established ineach laboratory that employs the method. The measurement uncertainty of any concentration value used for a comparisonshouldshall be recorded with the concentration.5.6 Acid digestion o
27、f glass followed by either Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) orInductively Coupled Plasma-Mass Spectrometry (ICP-MS) may also be used for trace elemental analysis of glass, and offer similardetection levels and the ability for quantitative analysis. However, these me
28、thods are destructive, and require larger sample sizesand much longer sample preparation times (Test Method E2330).5.7 Micro X-Ray Fluorescence (-XRF) uses comparable sample sizes to those used for LA-ICP-MS with the advantage ofbeing non-destructive of the sample. Some of the drawbacks of -XRF are
29、poorer sensitivity and precision, and longer analysistime.5.8 Scanning Electron Microscopy with EDS (SEM-EDS) is also available for elemental analysis, but it is of limited use forforensic glass source discrimination due to poor detection limits for higher atomic number elements present in glass at
30、traceconcentration levels. However, distinguishing between sources having similar RIs and densities is possible.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the s
31、tandards Document Summary page on the ASTM website.E2927 1626. Apparatus6.1 LA-ICP-MSALaserAblation system coupled to an ICP-MS instrument is employed. Since there are several manufacturersfor both laser ablation units and ICP-MS instruments, the instrument maker, model, configuration, and major ope
32、rationalparameters (that is, laser wavelength for the laser and mass selective detector type for the ICP-MS) of both instruments shouldshallbe noted within the analysis results. The most common laser wavelengths used for glass analysis are 266 nm, 213 nm, and 193nm. Either quadrupole or magnetic sec
33、tor ICP-MS instruments are suitable for this test method.6.2 Prior to the analysis on the day it is used, the ICP-MS shouldshall be tuned according to the manufacturersrecommendations covering the mass range of the elements to be measured. The instrument shouldshall be adjusted for maximumsensitivit
34、y, best precision, and to minimize oxides and doubly charged ion interferences. The use of a well-characterized glassstandard, reference material, such as NIST 612,4 is recommended during the tuning and performance check. Detector crosscalibrations (pulse/analog) shouldshall be performed before any
35、measurements when two detector modes are used in the analysis.6.3 In order to prepare for data acquisition, the signals of the following isotopes are monitored in the ICP-MS; lithium (7Li),magnesium (24 or 25Mg), aluminum (27Al), silicon (29Si), potassium (39K), calcium (42Ca), iron (57Fe), titanium
36、 (49Ti), manganese(55Mn), rubidium (85Rb), strontium (88Sr), zirconium (90Zr), tin (118Sn), barium (137Ba), lanthanum (139La), cerium (140Ce),neodymium (146Nd), hafnium (180Hf) and lead (208Pb). This procedure may be applicable to other elements and other isotopes (forexample, 206, 207Pb); however,
37、those elements listed above are considered to provide the most discrimination power for soda-limeglass comparisons. Alternatively, other isotopes such as 56Fe canmay be monitored using ICP-MS with advanced technology toremove interferences (for example, sector field ICP-MS or reaction cells).6.4 Eit
38、her argon or helium canmay be used as a carrier gas to transport the particles from the ablation cell to the plasma. Theuse of helium carrier gas has been reported to result in fewer fractionation effects than the use of argon as a carrier (6).7. Hazards7.1 Commercial laser ablation units are enclos
39、ed type I lasers. However, laser systems typically used for analysis of glassgenerate high energy radiation that canmay pose serious risks to eye safety if exposed to the eye. Interlocks shouldshall not bebypassed or disconnected.7.2 The argon plasma shouldshall not be observed directly without prot
40、ective eyewear. Potentially hazardous UV light may beemitted.7.3 ICP-MS instruments generate high amounts of radiofrequency energy in their RF power supply and torch boxes that ispotentially hazardous if allowed to escape. Safety devices and safety interlocks shouldshall not be bypassed or disconnec
41、ted.8. Calibration and Standardization8.1 A calibration curve using multiple glass standards or using a single glass standard canmay be used for quantitation forLA-ICP-MS analysis of glass. Any standard used to create the calibration should calibration standard shall be matrix-matched tothe sample a
42、nd well-characterized. The calibration standard(s) mustshall be traceable to an accepted standard. For glass analysisthere are several standards that are available such as the NIST Standard Reference Materials (that is, NIST 610, NIST 612, NIST614) and the float glass standard glasses (FGS1, FGS2) e
43、valuated by the European group NITECRIME (5) and distributed by theBundeskriminalamt, Germany.5 An internalA normalization standard, preferably silicon (29Si), mustshall be used to normalize thesignal. The use of an internala normalization standard is needed to adjust for differences in ablation yie
44、ld between the ablatedmaterials. Since silicon is present as a major component in all soda-lime glass (70 to 72 % as SiO2) (3, 7), a low abundanceisotope (29Si) is commonly used as the internalnormalization standard for this method. If this method is used for the analysis ofother glass types, the co
45、ncentration of the internalnormalization standard mustshall be determined prior to quantitative analysis.8.2 In addition to the calibration standard, at least one additional glass verification standard standard reference material shallshould be measured with each sample set as a quality control chec
46、k for the accuracy and precision of the method. The qualitycontrol specifications shouldshall be set by each laboratory.8.3 As a minimum, calibration standards are required at the beginning and the end of the analytical sequence in order to adjustfor instrument drift over time. Acceptance criteria f
47、or the calibration mustshall be defined by each laboratory and shouldshallinclude the use of calibration verification standards.9. Procedure9.1 If necessary, samples may be cleaned to remove any surface contamination by washing or pre-ablation, or both, prior toanalysis. Cleaning may include washing
48、 samples with soap and water, with or without ultrasonication, and rinsing in deionizedwater, followed by rinsing in acetone, methanol, or ethanol, and drying. Soaking in various concentrations of nitric acid for 304 Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr
49、., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.5 Available from Bundeskriminalamt, Section KI 35, 65173 Wiesbaden, Germany, http:/www.bka.de.E2927 163minutes or longer, rinsing with deionized water and ethanol, and drying prior to analysis removes most surface contaminationwithout affecting the measured concentrations of elements inherent in the glass. However, the use of nitric acid may remove somesurface coatings that may be present.9.2 Multiple samples and standards canmay be placed together in the ablation cell as long as their positions are do
