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<br />Note: For values near the detection limit: <br />1) The detection level is defined as twice the standard deviation of the noise <br />level, or in practical application, tvice the noise level. <br />2) Results may be reported with 66;~ confidence, by definition, at 1 standard <br />deviation of the detection limit. In practical application, results <br />approaching the detection limit are only good (969 confidence) plus or minus <br />2 times the detection limit. This is why values differ between dissolved <br />and total metals or between preserved and non-preserved total metals when <br />the values approach the detection limit. This is the limitation of the <br />instrumentation alone, regardless of analytical problems with preservation, <br />contamination, or loss in digestion, which can be assumed negated in order <br />to get results to fall in this range. <br />Several samples have ion balance problems. The major anions and rations were <br />reanalyzed to check for analytical errors. In an attempt to reconcile these pro- <br />blems, several other checks were made: <br />1) Hardness values were checked between data calculated from dissolved Calcium, <br />Magnesium and Manganese analyses, and data obtained by hardness titration; <br />2) The total amount of dissolved solids was calculated from the values obtained <br />in individual analyses and compared with the amount of dissolved solids <br />determined gravimetrically. <br /> <br />;) The ratio of dissolved solids (in mg/1) to specific conductance (in umhos/cm) <br />was checked to see if it was in an acceptable range (0.55 - 0.70). Those <br />samples with poor ion balances seem to check fairly well in these categories.- <br />vice A. Hale <br />Section Supervisor <br />as <br />L <br />n. L: uaco s, rn.u., ringr. <br />Instrume al Analysis Div. <br />COMMERCIAL TESTING & ENGINEERING CO. <br />.. ~~ C: O'. VV d12~m]f4PO <br />-. Cyr ?~OI~![I~On <br />