Optimization of extraction conditions and determination of the Chlorpyrifos, Diazinon, and malathion residues in environment samples: Fruit (Apple, Orange, and Tomato)

Abstract

Organophosphate (OP) insecticide, such as diazinon is found in the environments like water which is still approved for agricultural uses. When diazinon residues enter the human body, it functions as an acetylcholinesterase (AChE) inhibitor. This research aims to measure of chlorpyrifos (CPF), diazinon, and malathion residues in fruit such as apple, orange, and tomato after optimizing extraction conditions. Pesticide residues are measured by gas chromatography (GC) technique. Effective variables on pesticide residues are studied including pesticides kind, sampling station, and fruit kind. Results show that average concentration CPF, diazinon, and malathion residues in orange water are 7.05 ± 0.01 mg L^-1, 6.66 ± 0.03 mg L^-1, and 12.38 ± 0.02 µgL^-1, respectively. The average concentration CPF, diazinon, and malathion residues in apple water are 0.74 ± 0.02 mgL^-1, 0.70 ± 0.01 mgL^-1, and 1.10 ± 0.01 µgL^-1, respectively. The average concentration CPF, diazinon, and malathion residues in tomato water are 0.60 ± 0.02 mgL^-1, 0.57 ± 0.02 mgL^-1, and 0.89 ± 0.01 µgL^-1, respectively. The highest CPF concentration is observed in the orange fruit from station 20. Due to an appropriate storage condition and presenting organic fruits in the supermarket, the least mean concentration of pesticides is obtained in studied fruits from station 2. The manner of washing, peeling, and storage period before consuming fruits lead to decreasing studied pesticides concentration about 15-35, 40-50, and 50-60%, respectively. Increasing the fruit shelf-life led to decreasing studied pesticides concentration. Between pesticide concentration and variables: pesticides kind, sampling station, fruit kind, are not seen meaningful statistic relationship (P > 0.05). This study showed that pesticide residues in fruits can be decreased by washing, refrigerating, peeling procedures and increase in public surveillance.

Keywords: Chlorpyrifos (CPF); Diazinon; Environment sample; Gas chromatography (GC); Malathion; Organophosphate (OP).

Fig. 1

Chromatogram of standard pesticide solutions with a concentration of 500 μgkg⁻¹ using the internal standard (1- Diazinon, 2- Malation, 3- CPF).

Fig. 2

Location map of Tehran city.

Fig. 3

The effect of retention time on the measurement of the insecticides.

Fig. 4

The effect of solvent on the measurement of the insecticides.