Determination of thiophanate methyl and carbendazim residues in vegetable samples using microwave-assisted extraction.
Microwave-assisted extraction (MAE) was carried out for the determination of the fungicides thiophanate methyl [1.2-alpha-(3-methoxycarbonyl-2-thioureido)benzene] and carbendazim (methyl benzimidazol-2-ylcarbamate) in vegetable samples. Two vegetable samples, cabbage and tomatoes, were fortified with the two pesticides and subjected to MAE followed by cleanup to remove co-extractives prior to analysis by high-performance liquid chromatography (HPLC). Using the selected microwave exposure time and power setting, the recoveries of carbendazim ranged from 69 to 75%. But thiophanate methyl could not be recovered as the parent compound. It was converted and recovered as carbendazim. The conversion was quantitative as confirmed by high-performance liquid chromatography-mass spectrometry (HPLC-MS).
Singh
Shashi B
SB
Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi 12, India. sbs_agch@yahoo.com
Foster
Gregory D
GD
Khan
Shahamat U
SU
D001562:Benzimidazoles / Q000032:analysis* / Q000737:chemistry; D002219:Carbamates / Q000032:analysis* / Q000737:chemistry; D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D008872:Microwaves; D015394:Molecular Structure; D015203:Reproducibility of Results; D013875:Thiophanate / Q000032:analysis* / Q000737:chemistry; D014675:Vegetables / Q000737:chemistry*
D001562:Benzimidazoles; D002219:Carbamates; D013875:Thiophanate; C006698:carbendazim