Laserfiche WebLink
' GT ENVIRONMENTAL LABORATORY (GTEL) <br /> . STANDARD OPERATING PROCEDURE <br /> CONCERNING FIELD PRESERVATION OF BTX SAMPLES <br />' BY ACIDIFICATION <br /> SOP 12 <br />' If specially prepared acidified vials are not available, apply <br /> the following Field Procedures, using the field acidification <br /> kit. Thg kit contains: <br />' a) 500 cc glass measuring cup or breaker. <br /> b) dropping bottle of 50% hydrocloric acid or nitric <br /> acid. <br />' c) narrow range pH paper, 1 .0-2 .5 pH range . <br /> d) glass stirring rod. <br />' 1. Collect approximately 300cc of water in beaker. Try to <br /> minimize turbulence, bubbling, and time of exposure to the <br /> air. <br />' 2 . For inorganic analysis: use 5o% nitric acid <br /> For volatile organic analysis : use 50% hydrocloric acid <br /> Add 30 drops of 50$ acid to measuring cup. Hold dropper <br />' completely vertically. <br /> lie 3 . Gently mix with glass bar. <br /> 4 . Remove bar and touch wetted tip to the pH paper and check <br /> color code to assure it is below pH 2 . As more acid is <br /> added the pH goes lower. Discard used pH strip. <br /> I <br /> 5 . Add more acid if necessary. Toa much acid is not a problem, I <br /> just record how much was added (this will be helpful next <br />' time) . Don 't waste time trying to get it right - just add <br /> plenty of acid to get it below pH 2 . Ideally, once you know <br /> how much acid needs to be added at one well , that amount <br />' will be sufficient for the rest. However, test the pH each <br /> time . <br /> 6 . Pour the water into the vials prepared for that well and cap <br />' off with no bubbles inside. Again turbulence and bubbling <br /> are to be minimized. Also note that it is important that <br /> all of the vials for a given well be poured and sealed one <br />' right after another. Make sure the 300cc collected is <br /> enough to fill all of the vials with some to spare at the <br /> end. The volume collected can be increased but remember to <br /> Iproportionally increase the amount of acid added. <br /> 7. Acidificatfo6hdoes <br /> not <br /> airornextdayelivery <br /> replace chilling. <br /> dYs chill <br /> samples and P via <br /> I <br /> GRol %DARTER <br /> � TE--HNou►C% "'C <br />