Determination of herbicide residues in agricultural crops, foods, soil and water by chronometric method.
The method described is based on the biochemical detection of herbicides on a silica gel thin layer following their chromatographic separation. The detection reagent is a mixture of a homogenate of bean leaves (Phaseolus vulgaris) and of the redox indicator 2,6-dichloroindophenol. This chronometric determination of herbicide residues is based on the observation that dark blue inhibition zones appear on a pale yellow-green background during the exposure of the sprayed chromatoplates Silufol to light. The dark blue zones disappear again after a time, their lifetime is proportional to the amount of the herbicide in the zone. Because of the high selectivity and sensitivity of the biochemical detection this method does not require a multiple clean-up procedure, nor does it require sophisticated instrumentation. It equals gas chromatography in sensitivity and precision. The determination limit lies between 0.01 and 0.001 mg X kg-1, the average recovery rate is 85 to 90%.
D002736:Chloroplasts / Q000032:analysis; D002523:Edible Grain / Q000032:analysis; D005506:Food Contamination; D005618:Fresh Water / Q000032:analysis*; D005638:Fruit / Q000032:analysis; D006540:Herbicides / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D012987:Soil / Q000032:analysis*; D014675:Vegetables / Q000032:analysis; D014867:Water / Q000032:analysis*
D006540:Herbicides; D010573:Pesticide Residues; D012987:Soil; D014867:Water