CORRESPONDENCE_1984-1989 - Laserfiche WebLink

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t \'1 „ i o n N G. e Gf -10:2.2 Frtq ncy of�Anel ysi s of Blanks Method blanks provide an indicetior- Gf sitive interferences introduced within the laboratory. They hell :-t provioJe information on matrix effects, accuracy, recisior, or natural background. A rr.inimum of one method blank is anal y::ed at a Cf cr_` f c r e_h taL_n em; les vnricne\fr is more frequent to serify tnat trie iabCratory is not a source of contamination.. =ieId vlanks provide an indication of pcsitive interferences introdt!ced in the field and in t^e itaoratory. they w i 1 1 r:,L provide information on matrix effects, acc;..racy, precision, or natural rackgrc;und. Matrices used for control blanks will be determined to be fret of contamination prior to use. M eld blanks will be analyzed if the samples associated Witn the b?ank ccntein an analyte. 10.2.3 Frequency of Analysis of Replicate Samples pepl i Cate sarnp1es measure analytical precision end provide indications of the anaIytiCaI system. They will not provide indications of matrix effects or a=curacy. A minimum of one reel i Cate natural sampl e i s analyzed at a r. -.i nimum of once for each batch of semples or once for every ten samples whichever is more frequent. To obtain precision date for samples not containing analytes,. a matrix spike and matrix spike duplicate are analyzed at the same frequency. 10.2.4 Frequency of Analysis of Spiked Samples 81ank spikes(in a standard matrix) provide information on accuracy but will not indicate matrix effects or natural background. Spikes of natural samples provided in conjunction - -- -with analyses - of--un-spiked - samples provide information on matrix effects and natural background. A minimum of one spiked sample of each type describe above is analyzed at a minimum of once for each batch of samples or once for every ten samples whichever is more frequent.