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Wbodward•Csyde Consufta:tts <br /> II QUALITY CONTROL <br /> ------------------ <br /> A. PROJECT SPECIFIC QC. Spikes and duplicates were analyzed <br /> at approximately 100 of the sample load in order to establish <br /> field precision and laboratory accuracy and precision_. <br /> Field Precision is measured by using duplicate tests by <br /> Relative Percent Difference (RPD) as in: - <br /> I (sample concentration) - (duplicate sample concentration) ) <br /> R_'-'D = ---------------------------------------------------------- * 10G <br /> { mean concentration of sample and duplicate sample ) <br /> Laboratory Precision is measured by using duplicate spikes by <br /> Relative Percent Difference (RPD) as in: <br /> (Spike 1 sREC } - (Spike 2 %REC ) I <br /> RPD = -------------------------------------- * 100 <br /> ( mean %REC cf Spi:{e 1 and Spike 2 ) <br /> Laboratory Acc::racy (spite recovery) is measured by Percent <br /> Recovery (%REC) as in: <br /> ( spiked sample concentration ) - { sample concent_a .cr. ) <br /> %REC = ------------------------------------------------- * 100 <br /> ( true concentration of the spike ) <br /> See a--ac:ed e_- Pr=__=_:r.= and Labc_atcr_r Prec_s-c r. and Accuracy <br /> --.CC -E3:CF.:_.:•1CZE Pr-- z.+. a-., a c C U acr res :: ,c .,er_ <br /> -perr:r anca criteria-_=_ *::E-method. <br /> 5 <br /> C. METHOD BLANK RESULTS, A method blank is a laboratory-venerated <br /> sample which assesses the degree to which labcratcry cpe.at vr.s <br /> and pr,cedures cause false-positive analytical results for ycL_ <br /> samules. <br /> in t :e met^cd blanks asscc .ea with these samples, ta_ <br /> pzrame-ors were not detec-ea =t or above the practical aua.^.:_-=..ion j <br /> Zia :.'c� r?A:E.^,i. ,.--__ ==_3 a`LSe'`t _n Sect4cr -_- <br /> i <br /> I <br />