1、Designation: D7847 121D7847 17Standard Guide forInterlaboratory Studies for Microbiological Test Methods1This standard is issued under the fixed designation D7847; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1 NOTESubsection 1.2 and Section 4 were corrected editorially in March 2015.INTRODUCTIONMicrobiological parameters present a number of un
3、ique challenges relative to chemical and physicaltest methods apropos of the development of precision and bias terms. A number of these challengesare discussed in Guide E1326.As a working group (WG) we first grappled directly with some of theseissues during the development of Practice D6974. The dra
4、fts balloted at the D02.14 subcommitteelevel in February and June 2002, were balloted with the document identified as a Method. Moreover,the proposed Method was drafted as a harmonized document with the Energy Institutes (EI) MethodIP 385. When the item was balloted at D02 level, members of D02.94 c
5、ompelled us to change the titlefrom Method to Practice. The argument was that ASTM Methods list single series of steps that leadto a measurable result (a bit of data; quantitative, semi-quantitative or qualitative). Because D6974provides for the selection of different sample volumes (based on the es
6、timated culturable populationdensity) and different growth media (based on the sub-population to be quantified), it would only beaccepted as an ASTM Practice; not a Method. This issue of performing interlaboratory studies forculture methods will be discussed below.Since Practice D6974 was approved,
7、twofour microbiological Methods test methods have beenapproved byASTM: Method D7463 and Method , D7687.Although both methods measure adenosinetriphosphate (ATP) in fuel and fuel-associated water samples the method of obtaining the samplediffers; ASTM , D7463D7978 uses a liquid to liquid extraction w
8、hereas ASTM , and D7687D8070uses filtrationBecause these methods measure the concentration of a biomarker molecule, molecule ormicroorganisms, the issues that are relevant to ILS are similar to, but somewhat different than thosethat affect ILS for culture methods. Beckers2 investigated microbiologic
9、al test method ILS,interlaboratory studies, but advised several measures that are either impractical for or not relevant tothe methods that have been developed within D02: (1) Freeze inoculated samples after dispensing intoportions for shipment to participating labs; (2) Use a single organisms chall
10、enge; (3)Add the challengemicrobe to a sample matrix in which it is likely to proliferate.This guide will list key issues that must be addressed when designing ILS for Methods intended tomeasure the microbial properties of fuels and fuel-associated waters.1. Scope Scope*1.1 Microbiological test meth
11、ods present challenges that are unique relative to chemical or physical parameters, becausemicrobes proliferate, die off and continue to be metabolically active in samples after those samples have been drawn from theirsource.1.1.1 Microbial activity depends on the presence of available water. Conseq
12、uently, the detection and quantification of microbialcontamination in fuels and lubricants is made more complicated by the general absence of available water from these fluids.1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is
13、 the direct responsibility of SubcommitteeD02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved Dec. 1, 2012June 1, 2017. Published January 2013June 2017. Originally approved in 2012. Last previous edition approved in 2012 asD7847 121. DOI: 10.1520/D7847-12E01.10.1520/D7847-17
14、.2 Beckers, H. J., “Precision Testing of Standardized Microbiological Methods,” Journal of Testing and Evaluation, JTEVA, Vol. 14, No. 6, November 1986, pp.318-320.320.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes hav
15、e 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 as published by ASTM is to be considered the official doc
16、ument.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States11.1.2 Detectability depends on the physiological state and taxonomic profile of microbes in samples. These two para
17、meters areaffected by various factors that are discussed in this guide, and contribute to microbial data variability.1.2 This guide addresses the unique considerations that must be accounted for in the design and execution of interlaboratorystudies intended to determine the precision of microbiologi
18、cal test methods designed to quantify microbial contamination in fuels,lubricants and similar low water-content (water activity 1000 pg/mL in fuel; 10 000 pgmL in fuel-associated water: attribute score = 5.X1.3.3.4 The transformed data are provided in the ILS 1259 Research Report.6X1.3.4 When the re
19、sults of Test Method D7687 ILS 1259 were compared with those of Test Method D8070 ILS 1260, 72 %agreement between the two parameters was observed (Table X1.8).X1.3.5 The results of the comparison between the two methods indicates, combined with the results of the Test Method D7687TABLE X1.2 Prelimin
20、ary Intermediate Repeatability DataCellular ATP in Fuels and Fuel-Associated Water(ATP Data are in pg ATP/mL)Sample Replicate Average Range1 2 3E-0 gasoline A 33 31 27 30 6E-0 gasoline B 1100 1100 1300 1200 200E-0 gasoline C 20 000 21 000 15 000 18 000 6000E-10 gasoline A 39 27 28 31 13E-10 gasoline
21、 B 1000 1100 920 1000 180E-10 gasoline C 20 000 17 000 18 000 18 000 3000ULSD A 37 42 33 37 9ULSD B 890 1100 1100 1020 210ULSD C 24 000 22 000 25 000 24 000 3000Jet A A 31 30 24 28 7Jet A B 1000 1300 1300 1200 300Jet A C 21 000 20 000 19 000 20 000 2000B-5 A 42 34 41 39 8B-5 B 950 1200 1000 1100 250
22、B-5 C 21 000 23 000 21 000 22 000 2000B-20 A 41 34 44 40 10B-20 B 1100 1300 1300 1200 200B-20 C 17 000 22 000 23 000 21 000 6000E-10 bottom water A 37 36 28 34 8E-10 bottom water B 22 000 21 000 20 000 21 000 2000ULSD bottom water A 35 43 42 40 9ULSD bottom water B 18 000 17 000 15 000 17 000 3000Je
23、t A bottom water A 37 37 49 41 13Jet A bottom water B 16 000 20 000 19 000 18 000 4000TABLE X1.3 Bacterial Antigen Test ResultsSample Fuel Grade Analyst Replicate AVG Range1 21 Jet A1 1 1 1 1 02 1 1 1 02 Jet A1 1 3 3 3 02 3 3 3 03 Jet A1 1 5 5 5 02 5 5 5 04 EN590 1 1 1 1 02 1 1 1 05 EN590 1 3 3 3 02
24、 3 3 3 06 EN590 1 5 5 5 02 5 5 5 07 MGO 1 1 1 1 02 1 1 1 08 MGO 1 3 3 3 02 3 3 3 09 MGO 1 5 5 5 02 5 5 5 010 Bottoms-water 1 1 1 1 02 1 1 1 011 Bottoms-water 1 3 3 3 02 3 3 3 012 Bottoms-water 1 5 5 5 02 5 5 5 0D7847 178preliminary ILS (Research Report RR:D02-1720) support the hypothesis that actual
25、 biomass variability among replicatesubsamples was substantially greater than actual test method variability.X1.3.6 The contribution of between replicate biomass variability to total variability, illustrated by the ILS 1259 and ILS 1260 datacomparison supports the prescription (8.2.2.2(d) to draw re
26、plicate specimens from a single container. The benefits of doing so faroutweigh the potential risk of intentionally bias being introduced because operators know which specimens are replicates.TABLE X1.4 Total Fungal Antigen Test ResultsSample Fuel Grade Analyst Replicate AVG Range1 21 Jet A1 1 1 1 1
27、 02 1 1 1 02 Jet A1 1 3 3 3 02 3 3 3 03 Jet A1 1 5 5 5 02 5 5 5 04 EN590 1 1 1 1 02 1 1 1 05 EN590 1 3 3 3 02 3 3 3 06 EN590 1 5 5 5 02 5 5 5 07 MGO 1 1 1 1 02 1 1 1 08 MGO 1 3 3 3 02 3 3 3 09 MGO 1 5 5 5 02 5 5 5 010 Bottoms-water 1 1 1 1 02 1 1 1 011 Bottoms-water 1 3 3 3 02 3 3 3 012 Bottoms-wate
28、r 1 5 5 5 02 5 5 5 0TABLE X1.5 Hormoconis resinae Antigen Test ResultsSample Fuel Grade Analyst Replicate AVG Range1 21 Jet A1 1 1 1 1 02 1 1 1 02 Jet A1 1 3 3 3 02 3 3 3 03 Jet A1 1 5 5 5 02 5 5 5 04 EN590 1 1 1 1 02 1 1 1 05 EN590 1 3 3 3 02 3 3 3 06 EN590 1 5 5 5 02 5 5 5 07 MGO 1 1 1 1 02 1 1 1
29、08 MGO 1 3 3 3 02 3 3 3 09 MGO 1 5 5 5 02 5 5 5 010 Bottoms-water 1 1 1 1 02 1 1 1 011 Bottoms-water 1 3 3 3 02 3 3 3 012 Bottoms-water 1 5 5 5 02 5 5 5 0TABLE X1.6 Test Method D8070 Preliminary ILS OutcomeStatistic Bacte-riaFungi H. ResinaeWithin-operator disagreement probability 0 % 0 % 0 %Between
30、-operator disagreement probability 0 % 0 % 0 % misclassification between operators 0 % 0 % 0 %D7847 179SUMMARY OF CHANGESSubcommittee D02.14 has identified the location of selected changes to this standard since the last issue(D7847 121) that may impact the use of this standard. (Approved June 1, 20
31、17.)(1) Added new Test Methods D7978 and D8070 to Referenced Documents.(2) Added referenced to Test Method D8070 to subsection 6.2.1.(3) Added new subsections 8.2.1.1 and 8.2.1.2.(4) Added new Appendix X1.ASTM International takes no position respecting the validity of any patent rights asserted in c
32、onnection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the resp
33、onsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful
34、 consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International,
35、100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM
36、 website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ X1.7 ILS 1260 Outcome7Statistic Bacteria Fungi H. ResinaeWithin-operator disagreement probability 16 % 13 % 2
37、0 %Between-operator disagreement probability 28 % 23 % 26 % misclassification between operators 14 % 12 % 11 %TABLE X1.8 ILS 1259 cATP dataILS 1260 Lateral Flow Device Data Agreement Assessment; n=192Lab REP EN590L EN590M EN590H Jet A-L Jet A-M Jet A-H MFO-L MFO-M MFO-H Water-L Water-M Water-H1 1 1
38、1 1 1 1 1 1 12 1 1 1 1 1 1 1 1 12 1 1 1 1 1 1 1 1 1 1 12 1 1 1 1 1 1 1 1 1 13 1 1 1 1 1 1 1 1 12 1 1 1 1 1 1 1 14 1 1 1 1 1 1 1 1 1 1 12 1 1 1 1 1 1 15 1 1 1 1 1 1 1 1 1 12 1 1 1 1 1 1 1 1 16 1 1 1 1 1 1 1 12 1 1 1 1 1 1 1 1 17 1 1 1 1 1 1 1 1 1 1 12 1 1 1 1 1 1 1 1 18 1 1 1 1 1 1 1 12 1 1 1 1 1 1 1 1192 16 4 15 12 13 10 12 12 14 14 1 16 139n=192 % AGR 72 %D7847 1710
