Laserfiche WebLink
9.0 METHOD PERFORMANCE <br /> 9.1 Ruggedness. Two ruggedness studies have been performed to determine <br /> the effect of various perturbations on specific elements of the TCLP protocol . <br /> Ruggedness testing determines the sensitivity of small procedural variations <br /> which might be expected to occur during routine laboratory application. <br /> 9.1.1 Metals - The following conditions were used when leaching <br /> a waste for metals analysis: <br /> Varying Conditions <br /> Liquid/Solid ratio 19:1 vs . 21:1 <br /> Extraction time 16 hours vs. 18 hours <br /> Headspace 20% vs. 60% <br /> Buffer #2 acidity 190 meq vs . 210 meq <br /> Acid-washed filters yes vs . no <br /> Filter type 0.7 um glass fiber vs. 0.45 um <br /> vs. polycarbonate <br /> Bottle type borosilicate vs. flint glass <br /> Of the seven method variations examined, acidity of the extraction <br /> fluid had the greatest impact on the results. Four of 13 metals from an <br /> API separator sludge/electroplating waste (API/EW) mixture and two of <br /> three metals from an ammonia lime still bottom waste were extracted at <br /> higher levels by the more acidic buffer. Because of the sensitivity to pH <br /> changes , the method requires that the extraction fluids be prepared so <br /> that the final pH is within + 0.05 units as specified. <br /> 9.1.2 Volatile Organic Compounds - The following conditions were <br /> used when leaching a waste for VOC analysis: <br /> Varying Conditions <br /> Liquid/Solid ratio 19:1 vs. 21:1 <br /> Headspace 0% vs. 5% <br /> Buffer #1 acidity 60 meq vs. 80 meq <br /> Method of storing extract Syringe vs . Tedlar® bag <br /> Aliquotting yes vs. no <br /> Pressure behind piston 0 psi vs . 20 psi <br /> CD-ROM 1311- 22 Revision 0 <br /> July 1992 <br />