6515-38-4Relevant articles and documents
Highly sensitive enzyme-linked lmmunosorbent assay for chlorpyrifos. Application to olive oil analysis
Brun, Eva M.,Garces-Garcia, Marta,Puchades, Rosa,Maquieira, Angel
, p. 9352 - 9380 (2005)
Highly sensitive enzyme-linked immunoassays for chlorpyrifos, one of the most applied insecticides, are presented. Several haptens were synthesized for immunoreagent production and ELISA development. The best immunoassays obtained are based on an indirect coated-plate immunoassay format. Two assays were optimized; one shows a limit of detection of 0.3 ng L-1, an I 50 of 271 ng L-1, and a dynamic range between 4 and 16 474 ng L-1. The other one has a limit of detection of 0.07 ng L -1, an I50 of 7 ng L-1, and a dynamic range between 0.4 and 302 ng L-1. The assays were used to quantify chlorpyrifos in olive oil using a simple and rapid sample extraction procedure. The good recoveries achieved in both assays (109% mean value) and the agreement with values given by the GC reference method (110% mean value) indicate their potential for either screening or laboratory quantification.
Reaction of chlorpyrifos-methyl in aqueous hydrogen sulfide/bisulfide solutions
Jans, Urs,Miah, M. Hasan
, p. 1956 - 1960 (2003)
The kinetics of the reactions of chlorpyrifos-methyl, an organophosphorus insecticide, with hydrogen sulfide (H2S) and bisulfide (HS-) were determined in well-defined aqueous solutions. The resulting pseudo-first-order rate constant for chlorpyrifos-methyl with bisulfide yielded a second-order rate constant of (2.1 ± 0.3) × 10-3 M-1 s-1. The second-order rate constant for chlorpyrifos-methyl with hydrogen sulfide is significantly slower than the second-order rate constant with bisulfide. The contribution of H2S to the observed degradation rate constant of chlorpyrifos-methyl at concentrations of up to 4 mM H2S is not significant. The second-order rate constant of chlorpyrifos-methyl with H2S was too low to be measured in this study. The results indicate that HS- present at environmentally relevant concentrations may represent an important sink for phosphorothionate triesters in a coastal marine environment, while H2S reacts too slowly to be environmentally relevant (pH 6-9). Trichloropyridinol, the major product of hydrolysis of chlorpyrifos-methyl, is only a minor product of the reaction of chlorpyrifos-methyl with bisulfide; however, trichloropyridinol was found to be stable under the experimental conditions.
Biodegradation of chlorpyrifos and 3,5,6-trichloro-2-pyridinol by the epiphytic yeasts Rhodotorula glutinis and Rhodotorula rubra
Bempelou,Vontas,Liapis,Ziogas
, p. 1368 - 1378 (2018)
The possible involvement of the epiphytic yeasts Rhodotorula glutinis and Rhodotorula rubra in the biodegradation of the insecticide chlorpyrifos and its metabolite 3,5,6-trichloro-2-pyridinol (TCP), in pure cultures and in plant surfaces (tomato fruits) was investigated. Higher biodegradation rates were observed as the concentration of chlorpyrifos and the inoculum of the microorganisms were increased, while the yeasts proved to be more active at 25 and 15 °C. The presence of glucose in the mineral nutrient medium, as an extra source of carbon, delayed the biodegradation by Rhodotorula glutinis, while Rhodotorula rubra proved to be more active. The detection and quantification of the parent compound and TCP was successfully achieved using a LC/MS/MS chromatographic system. The in vitro enzymatic assays applied suggested that esterases may be involved in the biodegradation of chlorpyrifos, a fact that was further enhanced after the addition of the synergists triphenyl phosphate, diethyl maleate and piperonyl butoxide in the biodegradation trials. The decrease of chlorpyrifos residues on tomato fruits confirmed the corresponding on pure cultures, resulting in the suggestion that the yeasts R. glutinis and R. rubra can possibly be used successfully for the removal or detoxification of chlorpyrifos residues on tomatoes.
Monitoring of the organophosphate pesticide chlorpyrifos in vegetable samples from local markets in Northern Thailand by developed immunoassay
Hongsibsong, Surat,Prapamontol, Tippawan,Xu, Ting,Hammock, Bruce D.,Wang, Hong,Chen, Zi-Jian,Xu, Zhen-Lin
, p. 1 - 14 (2020/07/04)
Chlorpyrifos is an organophosphate pesticide that is wildly used among farmers for crop protection. However, there are concerns regarding its contamination in the environment and food chain. In the present study, an in-house indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) specific for detecting chlorpyrifos is developed and validated against gas chromatography–flame photometric detection (GC-FPD) as the conventional method. The developed ic-ELISA was used for detecting chlorpyrifos residue in vegetable samples. The developed ic-ELISA showed good sensitivity to chlorpyrifos at an IC50 of 0.80 μg/kg, with low cross-reactivity to other organophosphate pesticides. The 160 samples were collected from local markets located in the Chiang Rai, Chiang Mai, and Nan provinces in northern Thailand. The positive rate of chlorpyrifos residues in the vegetable samples was 33.8percent, with the highest levels found in cucumbers, coriander, and morning glory, at 275, 145, and 35.3 μg/kg, respectively. The highest median levels of chlorpyrifos found in the detected samples were Chinese cabbage (332 μg/kg), cucumber (146.3 μg/kg) and Chinese Kale (26.95 μg/kg). The developed ic-ELISA is suitable for the rapid quantitation of chlorpyrifos residues.
Synthesis and herbicidal activities of aryloxyacetic acid derivatives as HPPD inhibitors
Huang, Hao,Liu, Jian-Min,Shu, Lei,Wang, Man-Man,Yan, Yi-Le,Zhang, Da-Yong,Zhang, Jian-Qiu
supporting information, p. 233 - 247 (2020/03/27)
A series of aryloxyacetic acid derivatives were designed and synthesized as 4-hydoxyphenylpyruvate dioxygenase (HPPD) inhibitors. Preliminary bioassay results reveal that these derivatives are promising Arabidopsis thaliana HPPD (AtHPPD) inhibitors, in particular compounds I12 (Ki = 0.011 μM) and I23 (Ki = 0.012 μM), which exhibit similar activities to that of mesotrione, a commercial HPPD herbicide (Ki = 0.013 μM). Furthermore, the newly synthesized compounds show significant greenhouse herbicidal activities against tested weeds at dosages of 150 g ai/ha. In particular, II4 exhibited high herbicidal activity for pre-emergence treatment that was slightly better than that of mesotrione. In addition, compound II4 was safe for weed control in maize fields at a rate of 150 g ai/ha, and was identified as the most potent candidate for a novel HPPD inhibitor herbicide. The compounds described herein may provide useful guidance for the design of new HPPD inhibiting herbicides and their modification.
Photolysis of chlorpyrifos-methyl, chlorpyrifos-methyl oxon, and 3,5,6-trichloro-2-pyridinol
Lobatto, Virginia L.,Argüello, Gustavo A.,Buján, Elba I.
supporting information, (2019/04/08)
The photodegradation of chlorpyrifos-methyl (1), and two of its photodegradation products, chlorpyrifos-methyl oxon (2), and 3,5,6-trichloro-2-pyridinol (3) was studied using low pressure Hg lamps irradiating at 254?nm either in pure acetonitrile (ACN) or in 10% ACN/H2O. Experiments conducted in pure ACN allowed us to identify the photoproducts in the photolysis of 1, 2, and 3 both, in air saturated samples and in the absence of oxygen as analyzed by gas chromatography–mass spectrometry (GC-MS), high resolution mass spectrometry (HRMS), and phosphorus-31 nuclear magnetic resonance (31P NMR). Since 2 and 3 are products in the photodegradation of 1, their degradations in 10% ACN/H2O were independently measured, and it was determined that 1 and 2 degrade at comparable rates. Instead, 3 does not interfere in the measurement since it degrades much faster, and their products do not absorb in the region of 1. Our results indicate that short wave photolysis could become a plausible detoxification mechanism.
