The Quantity Analysis of Organophosphate Pesticide Residue in Agricultural Products of Amphur Muang Loei

Abstract

The quantity analysis of organophosphate pesticide residue , methylparathion, mevinphos
and monochrotophos in 14 agricultural products such as lettuce, tomato, cauliflower, green chilli,
cabbage, kale, yard long bean, cucumber, white greens, Chinese cabbage, grape, orange , apple and
guava collected from two locations, in morning market and evening market in Amphur Muang ,
Loei province during April - July 2004 was determined. The samples were extracted by acetone,
hexane and dichloromethane and passed through the anhydrous sodium sulphate column. The
qualitative and quantitative analysis were studied by Gas Chromatography with DB ??? 17 column,
using helium gas as mobile phase and FTD detector.
From the analysis, it was found methyl parathion in orange 0.11 ppm in April , grape and
apple 0.52 , 0.11 ppm in May , mevinphos in cauliflower 0.40 ??? 6.51 ppm , cabbage and grape 1.73 ,
0.75 ppm in April , mevinphos in cauliflower 0.11 ppm, lettuce 0.07 ppm ,cabbage 0.09 ??? 0.52 ppm,
yard long bean 0.07 ppm and grape 0.84 ppm in May , a mevinphos in cabbage 3.8 ppm in July.
However, the monochrotophos was not detected. Inconclusion The organophosphates in sample over
standard Codex were methyparathion in grape (>0.2 ppm ), mevinphos in cauliflower (>1 ppm ),
cabbage (> 1 ppm) and grape (>0.5 ppm ). The percent recovery of methylparathion and mevinphos
were 85.63 and 93.58 respectively. The LOD, LOQ of methylparathion were 0.016 and 0.053 ppm ,
mevinphos were 0.015 and 0.05 ppm ,monochrotophos were 0.018 and 0.060 ppm respectively.