Vol.5 No.4 2013

Research paper : Standardization of environmental analysis methods of hazardous chemicals (S. Taniyasu et al.)−276−Synthesiology - English edition Vol.5 No.4 (2013) to investigate the isomer composition in the NP mixture before hand, using the gas chromatograph flame ionization detector (GC-FID)Term 5. For the method development of NP, isomer compositions of the mixtures supplied by five reagent manufacturers were analyzed, and their coefficient of variation (value obtained by dividing the standard deviation by arithmetic mean; indicates relative variation) was 14 % (slightly different by isomers). To use the mixture for which the valuation of the isomer composition is done by the measurer him/herself as the quantifying standard substance is exceptional in the ISO standard. This point was discussed thoroughly in the DIS stage, and it was confirmed that there was hardly any variation in the composition among the reagent manufacturers,[22] and the information for the composition of mixtures from the five commercial companies were included in the Annex (Informative).3.2 Development of the analysis method for PFOS/PFOAAt the time when general research for PFOS/PFOA was started in 2000, most analysis was conducted in blood samples which were considered as high concentration samples, and the analysis of environmental water was barely done. The reported analysis values had high detection limit due to background contamination, and there was no highly reliable analysis technology for low concentration environmental water. Therefore, research was done from 2001 in cooperation with the Wadsworth Center of the United States based on the solid phase extraction (SPE)[23] method using the existing octadecyl group (C18).[11] Until the new proposal of ISO 25101 in June 2005, we conducted the research to clarify the quality control condition to obtain highly reliable analysis data, by applying the developed PFOS/PFOA analysis method to various environmental samples.[11][12][14][24]-[29] The first issue in PFOS/PFOA analysis was the reduction of background contamination.[12] This was because the fluororesins such as the polytetrafluoroethylene (PTFE) that were used in various places around us as functional materials has became the contamination source, and also, system blank (contamination arising from the analysis device) tended to The 4-NP mixture is separated into 13 peaks in the general GC(in case 5 % phenylpolydimethylsiloxane column is used).Retention time (min)Retention time (min)Conventional methodISO 18857‐1: 2005 [9]JIS K 0450‐20‐10: 2005 [5]m/z 1351311753213121110786432113121110879654321AbundanceAbundanceRetention time (min)New standardISO 24293: 2009 [1]JIS K 0450‐60‐10: 2007 [2]18.0017.8017.6017.4017.2017.00260018001000200m/z 191m/z 163m/z 149m/z 135m/z 121Total ion chromatograph (TIC)45003500250015005001300090005000100035000250001500050009000700050003000100055000450003500025000150005000(Right) New standard: Peaks with good separation and sensitivity for the 13 types of 4-NPs are selected for each isomer from multiple m/z, and quantification is done using the relative response factor (RRF) against the internal standard sub-stance. Assessment by individual isomers is possible.(Top) Conventional method: Total amount of 4-NP is calculated using the main peaks detected at m/z 135. Quantifica-tion is not done for different isomers.350002500015000500091264311087113119643113117532AbundanceAbundanceAbundanceAbundanceAbundanceFig. 5 Comparison of the NP analysis methods using GC-MSThe numbers above the chromatographs show the individual 4-NP isomers. The underlined numbers show the peaks designated by ISO standard to be used for quantification.


page 52