Dissipation, half-lives, and mass spectrometric identification of chlorpyrifos and its two metabolites on field-grown collard and kale

• Published in: Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes Vol. 52; no. 4; pp. 251 - 255
• Main Authors: Antonious, George F., Turley, Eric T., Abubakari, Mutari, Snyder, John C.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 03-04-2017; Taylor & Francis Ltd
• Subjects: 3, 5, 6-trichloro-2-pyridinol; Brassica; Brassica - chemistry; Brassica - drug effects; Chlorpyrifos - analogs & derivatives; Chlorpyrifos - analysis; Chlorpyrifos - metabolism; Chlorpyrifos - pharmacokinetics; chlorpyrifos oxon; Chromatography, Gas - instrumentation; Chromatography, Gas - methods; GC-MSD; Half-Life; Hydrolysis; Kentucky; Mass Spectrometry - methods; metabolites; Pesticide Residues - analysis; Pesticide Residues - pharmacokinetics; Plant Leaves - chemistry; Pyridones - analysis; Pyridones - pharmacokinetics; GC-MSD; 3, 5, 6-trichloro-2-pyridinol; chlorpyrifos oxon; half-life; metabolites
• ISSN: 0360-1234; 1532-4109
• DOI: 10.1080/03601234.2016.1270683

The persistence and fate of chlorpyrifos and its two metabolites, chlorpyrifos-oxon and the 3, 5, 6-trichloro-2-pyridinol (TCP) break-down product were investigated on kale and collard leaves under field conditions. A simultaneous extraction and quantification procedure was developed for chrorpyrifos and its two main metabolites. Residues of chlorpyrifos, chlorpyrifos oxon, and TCP were determined using a gas chromatograph (GC) equipped with an electron capture detector (GC/ECD). Chlorpyrifos metabolites were detectable up to 23 days following application. Residues were confirmed using a GC equipped with a mass selective detector (GC/MSD) in total ion mode. Initial residues of chlorpyrifos were greater on collard (14.5 µg g
−1
) than kale (8.2 µg g
−1
) corresponding to half-lives (T
1/2
) values of 7.4 and 2.2 days, respectively. TCP, the hydrolysis product, was more persistent on collards with an estimated T
1/2
of 6.5 days compared to kale (T
1/2
of 1.9 days).