Myanmar Health Sciences Research Journal
Volume 28, Number 2
TITLE: Determination of Pesticide Residues in Brassica Vegetables (Broccoli and Cauliflower) in Field Trial and Market Samples
AUTHOR: Nwe Haymar Lynn, Khin Chit, Yee Yee Tin, Tin Win, Myint Han, Mya Mya Moe & Swe Swe Aung
SOURCE: Myanmar Health Sciences Research Journal
ABSTRACT: Pesticides are chemicals used in agriculture to protect crops against destructive pests and thereby increasing food supply. The aim of this study was to assess the desirable safe waiting period between the last application of pesticides and release of the broccoli to the consumer and to determine pesticide residues in brassica vegetables (cauliflower and broccoli) from market samples. Laboratory-based, cross sectional descriptive study involved firstly, test field broccoli samples (Brassica italica) were sprayed with chlorpyrifos 40% EC (Emulsifiable concentrate) and were analyzed from treated and untreated plots by gas chromatography-flame photometric detector. Secondly, the rate of breakdown of chlorpyrifos pesticide in the plant foliage was also determined by half-life. The average initial deposit of 14.12 ppm was observed after the last application of chlorpyrifos at the recommended dosage of 35/gallon. The residue in broccoli dissipated below its MRL value after 7 days. The half-life period of chlorpyrifos in broccoli foliage was observed to be 2.4 days. Cauliflower and broccoli samples from local markets (10 samples) were analyzed for of pesticide levels by gas chromatography-mass spectrometry. Among market samples, three samples contained OPPs residues seemed to be chlorpyrifos in qualitative analysis but only one sample was found to be contaminated with chlorpyrifos residue about 1.2 ppm. Maximum residue limit of chlorpyrifos on broccoli was 2 ppm adopted by Codex. Market samples were observed to be treated with pesticides and pesticide levels may be declined below legal limits by the time food reached to consumers. But, market samples from over the country still needed to be analyzed to prevent human health hazard.
SUBJECT HEADINGS: Gas chromatography-flame photometric detector, Gas chromatography-mass spectrometry, Organophosphate pesticides residues