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rr Y <br /> r <br /> SECTION VI <br /> SPECIALIZED QUALITY CONTROL PROCEDURES <br /> A. Organics by Gas Chromatography <br /> Specialized quality control procedures for these analyses <br /> are typified by those used for Pesticides and PCB's by EPA <br /> method 608. For every nine samples analyzed, another three <br /> QC samples--a method blank, a duplicate, and a spike---are <br /> run. One QC control, sample is analyzed for every 100 <br /> client samples. The results are compared to the acceptance <br /> criteria listed by EPA in the Federal Register. If the <br /> result for a particular parameter does not meet the cri- <br /> teria, the sample is reanalyzed for that parameter. <br /> �~ B. Organics by GC/MS <br /> l`r 1. Volatile Organics; EPA Method 624 <br /> For every nine samples analyzed, a method blank, a <br /> duplicate, and a spike are also run. 'Three surrogates <br /> are added to each sample in order to monitor purging <br /> efficiency and instrument operation. A calibration <br /> standard containing a mixture of priority pollutants at <br /> the 20 ug/L level is analyzed once each shift. <br /> Each GC/MS instrument is checked and retuned on bromo- <br /> I fluorobenzene (BFB) for every shift. One blind QC <br /> sample is analyzed for every 100 client samples. <br /> 2. Base/Neutral and Acid Extractable Organics, EPA <br /> Method 625 <br /> Three quality control samples--a method blank, a dupli- <br /> cate, and a spike-rare run with Every batch of nine <br /> samples. Each GC/MS is calibrated daily to ensure that <br /> performance on decafluorotriphenyl phosphine (DFTPP) <br /> meets EPA criteria. Four surrogates and three internal <br /> standard are added to each sample in the batch of 12. <br /> A standard containing both base/neutral and acid <br /> priority pollutants is analyzed with each set of ex- <br /> tracts. A daily sensitivity mixture is run in order to <br /> evaluate chromatographic column performance and a blind <br /> QC sanple is analyzed for every 100 client samples. <br /> VI-1 <br />