Laserfiche WebLink
GT ENVIRONMENTAL LABORATORY (GTEL) <br /> STANDARD OPERATING PROCEDURE <br /> CONCERNING FIELD PRESERVATION OF BTEX SAMPLES BY ACIDIFICATION <br /> SOP 12 <br />' If specifically prepared acidified vials are not available, apply the following Field Procedures, using <br /> the field acidification kit The kit contains <br /> Ia) 500 cc <br /> b) dropping bottle of 50% hydrochloric acid or nitric 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 minimize turbulence, bubbling, and <br /> time of exposure to the air <br />' 2 For inorganic analysis use 50% nitric acid For volatile organic analysis use 50% <br /> 9 Y <br />' hydrochloric acid Add 30 drops of 50% acid to measuring cup Hold dropper completely <br /> vertically <br /> 3 Gently mix with glass bar <br /> 4 Remove bar and touch wetted tip to the pH paper and check color code to assure it is below <br /> pH 2 As more acid is added the pH goes lower Discard used pH strip <br />' 5 Add more acid if necessary too much acid is not a problem, dust record how much was <br /> added (this will be helpful next time) Don't waste time trying to get it right -dust add plenty <br /> of acid to get it below pH 2 Ideally, once you know how much acid needs to be added at <br /> one well, that amount will be sufficient for the rest However, test the pH each time <br /> 6 Pour the water into the vials prepared for that well and cap off with no bubbles inside Again <br />' turbulence and bubbling are to be minimized Also note that it is important that all of the <br /> vials for a given well be poured and sealed one right after another Make sure the 300cc <br /> collected is enough to fill at of the vials with some to spare at the end The volume collected <br /> can be increased but remember to proportionally increase the amount of acid added <br /> 7 Acidification does not replace chilling Always chill samples and ship via air for next day <br /> delivery <br /> GROUNDWATER <br /> �, J, TECHNOLOGY, INC <br />