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Method 102 Revision 1 7.3.6.2 If the duplicate analysis differs by more than 20%, and if the concentration of the sample is higher than 3X LOD, then an additional analysis is needed. 7.3.6.3 If the relative standard deviation (RSD) of the replicate analyses is greater than 15% and if the concentration of the sample is greater than 3 x LOD, none of the analyses for that day are acceptable. 7.3.6.4 If the range is within 20%, the mean and the standard deviation are reported. 7.3.7 Compound confirmation is a quality control procedure. 7.3.7.1 Ten percent of the analyses are to be confirmed by a different analytical system (different column or alternate detector, e.g. GC/MS). 7.3.7.2 If the confirmatory and the routine analyses differ by more than 20%, none of the analyses for that day are acceptable. 7.3.8 Analytical reports are filed. 7.3.8.1 Data storage: peak area and compound concentration data are stored unmodified in the electronic storage. Data are archived according to date, site, analysis, and project for easy retrieval. These data are kept for three years in the laboratory electronic storage. 7.3.8.2 All data above the minimum detection limits are report- ed to the requesting agency in hard copy or electronic format. 7.3.8.3 All reports are reviewed by at least two qualified staff before they are released. 8 Critique and Comments 8.1 The minimum measurable concentration of benzene has been determined to be 0.5 ppb using prescribed instrument conditions i.e. 40 mL sample, cryogenic trap. 8.1.1 Table 8.1.1 lists the lower limits of detection for the method and its associated statistics 8.2 The range of benzene measurement is 1.0 to 1000 ppb. The upper limit may be expanded by ext -ending the c.-alibration rsnge, by diluting the sample, or by re_1ducin,,.1 the sample volume. 8.3 Any organic compound present in the sample having a retention time similar to that of benzene under the