Table B.2 The mass balance for pendimethalin (low concentration) sorption to pond sediment. The recoveries were calculated relative to theoretical total activity and relative to the activity of controls Time Water Sediment Test glass Centrifuge tubes Total Theoretical total Control hours dpm dpm dpm dpm dpm dpm dpm Balance theoretical Balance control 3 1919 67283 42 101 69345 94179 73531 76% 94% 3 1856 66612 64 47 68579 94179 73531 75% 93% 24 1521 64649 56 25 66251 94179 77240 72% 86% 24 1521 41031 79 35 42666 94179 77240 47% 55% 168 1408 68897 65 29 70399 94179 73787 77% 95% 168 1440 70067 27 12 71546 94179 73787 78% 97% 480 1481 64748 134 59 66422 94179 73017 73% 91% 480 1456 69010 69 31 70566 94179 73017 77% 97% Average 72% 89%