ASTM D7876-13(2018)
(Practice)Standard Practice for Practice for Sample Decomposition Using Microwave Heating (With or Without Prior Ashing) for Atomic Spectroscopic Elemental Determination in Petroleum Products and Lubricants
Standard Practice for Practice for Sample Decomposition Using Microwave Heating (With or Without Prior Ashing) for Atomic Spectroscopic Elemental Determination in Petroleum Products and Lubricants
SIGNIFICANCE AND USE
5.1 Often it is necessary to dissolve the sample, particularly if it is a solid, before atomic spectroscopic measurements. It is advantageous to use a microwave oven for dissolution of such samples since it is a far more rapid way of dissolving the samples instead of using the traditional procedures of dissolving the samples in acid solutions using a pressure decomposition vessel, or other means.
5.2 The advantage of microwave dissolution includes faster digestion that results from the high temperature and pressure attained inside the sealed containers. The use of closed vessels also makes it possible to eliminate uncontrolled trace element losses of volatile species that are present in a sample or that are formed during sample dissolution. Volatile elements arsenic, boron, chromium, mercury, antimony, selenium, and tin may be lost with some open vessel acid dissolution procedures. Another advantage of microwave aided dissolution is to have better control of potential contamination in blank as compared to open vessel procedures. This is due to less contamination from laboratory environment, unclean containers, and smaller quantity of reagents used (9).
5.3 Because of the differences among various makes and models of satisfactory devices, no detailed operating instructions can be provided. Instead, the analyst should follow the instructions provided by the manufacturer of the particular device.
5.4 Mechanism of Microwave Heating—Microwaves have the capability to heat one material much more rapidly than another since materials vary greatly in their ability to absorb microwaves depending upon their polarities. Microwave oven is acting as a source of intense energy to rapidly heat the sample. However, a chemical reaction is still necessary to complete the dissolution of the sample into acid mixtures. Microwave heating is internal as well as external as opposed to the conventional heating which is only external. Better contact between the sample particles and th...
SCOPE
1.1 This practice covers the procedure for use of microwave radiation for sample decomposition prior to elemental determination by atomic spectroscopy.
1.1.1 Although this practice is based on the use of inductively coupled plasma atomic emission spectrometry (ICP-AES) and atomic absorption spectrometry (AAS) as the primary measurement techniques, other atomic spectrometric techniques may be used if lower detection limits are required and the analytical performance criteria are achieved.
1.2 This practice is applicable to both petroleum products and lubricants such as greases, additives, lubricating oils, gasolines, and diesels.
1.3 Although not a part of Committee D02’s jurisdiction, this practice is also applicable to other fossil fuel products such as coal, fly ash, coal ash, coke, and oil shale.
1.3.1 Some examples of actual use of microwave heating for elemental analysis of fossil fuel products and other materials are given in Table 1. (A) The boldface numbers in parentheses refer to the list of references at the end of this standard.
1.3.2 Some additional examples of ASTM methods for microwave assisted analysis in the non-fossil fuels area are included in Appendix X1.
1.4 During the sample dissolution, the samples may be decomposed with a variety of acid mixture(s). It is beyond the scope of this practice to specify appropriate acid mixtures for all possible combinations of elements present in all types of samples. But if the dissolution results in any visible insoluble material, this practice may not be applicable for the type of sample being analyzed, assuming the insoluble material contains some of the analytes of interest.
1.5 It is possible that this microwave-assisted decomposition procedure may lead to a loss of “volatile” elements such as arsenic, boron, chromium, mercury, antimony, selenium, and/or tin from the samples. Chemical species of the elements is also a concern in such dissol...
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This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7876 − 13 (Reapproved 2018)
Standard Practice for
Practice for Sample Decomposition Using Microwave
Heating (With or Without Prior Ashing) for Atomic
Spectroscopic Elemental Determination in Petroleum
1
Products and Lubricants
This standard is issued under the fixed designation D7876; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope arsenic, boron, chromium, mercury, antimony, selenium,
and/or tin from the samples. Chemical species of the elements
1.1 This practice covers the procedure for use of microwave
is also a concern in such dissolutions since some species may
radiation for sample decomposition prior to elemental deter-
not be digested and have a different sample introduction
mination by atomic spectroscopy.
efficiency.
1.1.1 Although this practice is based on the use of induc-
tively coupled plasma atomic emission spectrometry (ICP- 1.6 A reference material or suitable NIST Standard Refer-
AES) and atomic absorption spectrometry (AAS) as the ence Material should be used to confirm the recovery of
primary measurement techniques, other atomic spectrometric analytes.Ifthesearenotavailable,thesampleshouldbespiked
techniques may be used if lower detection limits are required with a known concentration of analyte prior to microwave
and the analytical performance criteria are achieved. digestion.
1.2 This practice is applicable to both petroleum products 1.7 Additional information on sample preparation proce-
and lubricants such as greases, additives, lubricating oils, dures for elemental analysis of petroleum products and lubri-
gasolines, and diesels. cants can be found in Practice D7455.
1.3 Although not a part of Committee D02’s jurisdiction, 1.8 The values stated in SI units are to be regarded as
thispracticeisalsoapplicabletootherfossilfuelproductssuch standard. No other units of measurement are included in this
as coal, fly ash, coal ash, coke, and oil shale. standard.
1.3.1 Someexamplesofactualuseofmicrowaveheatingfor
1.9 This standard does not purport to address all of the
elemental analysis of fossil fuel products and other materials
safety concerns, if any, associated with its use. It is the
are given in Table 1.
responsibility of the user of this standard to establish appro-
1.3.2 Some additional examples of ASTM methods for
priate safety, health, and environmental practices and deter-
microwave assisted analysis in the non-fossil fuels area are
mine the applicability of regulatory limitations prior to use.
included in Appendix X1.
Specific warning statements are given in Sections 6 and 7.
1.10 This international standard was developed in accor-
1.4 During the sample dissolution, the samples may be
dance with internationally recognized principles on standard-
decomposed with a variety of acid mixture(s). It is beyond the
ization established in the Decision on Principles for the
scope of this practice to specify appropriate acid mixtures for
Development of International Standards, Guides and Recom-
all possible combinations of elements present in all types of
mendations issued by the World Trade Organization Technical
samples. But if the dissolution results in any visible insoluble
Barriers to Trade (TBT) Committee.
material, this practice may not be applicable for the type of
sample being analyzed, assuming the insoluble material con-
2. Referenced Documents
tains some of the analytes of interest.
2
2.1 ASTM Standards:
1.5 It is possible that this microwave-assisted decomposi-
C1234 Practice for Preparation of Oils and Oily Waste
tionproceduremayleadtoalossof“volatile”elementssuchas
Samples by High-Pressure, High-Temperature Digestion
for Trace Element Determinations
1
This practice is under the jurisdiction ofASTM Committee D02 on Petroleum
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-
2
mittee D02.03 on Elemental Analysis. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2018. Published June 2018. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2013. Last previous edition approved in 2013 as D7876 – 13. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D7876-13R18. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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