Abstract

SCHOSINSKY, Karl; QUINTANA GUZMAN, Eugenia María  and  RUEPERT, Clements. Optimization of a method for the detection of organophosphates and carbamates in vegetables. Acta bioquím. clín. latinoam. [online]. 2009, vol.43, n.1, pp.11-20. ISSN 0325-2957.

Optimization of the screening method of inhibition of human cholinesterases is considered important because of the high contamination rate of agricultural products with pesticides and its high detection cost. It has been demonstrated that erythrocytes and plasma are stable at least for three months at 4-8 °C. The colour reaction reagent is stable for at least two and a half years at 4-8 °C and the substrate for both cholinesterases is stable when frozen, at least for two years. The solution of vegetable extract and erythrocytes or plasma must be incubated 90 minutes at 37 °C in order to determine the percentages of enzymatic inhibition. It was established that inhibition percentages higher than 16% for the plasmatic solution, and 21% for the erythrocytic solution mean that pesticide is present in vegetables. The advantages of this optimized screening method for the detection of carbamates and organophosphates in vegetables are its low cost and its easy and quick analysis without the need of expensive equipment. This method does not quantify or identify the pesticide, but rather it differentiates organophosphates from carbamates if the incubation time of the vegetable extract with erythrocytes or plasma is maintained at 20- 25 °C for 24 hours.

Keywords : Plasmatic cholinesterase; Erythrocytic cholinesterase; Pesticide; Vegetable; Screening; Organophosphates; Carbamates.

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