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Degradation and residues of indoxacarb enantiomers in rice plants, rice hulls and brown rice using enriched S‐ indoxacarb formulation and enantiopure formulation
Author(s) -
Shi Lihong,
Gui Ting,
Zhao Shan,
Xu Jin,
Wang Fei,
Sui Changling,
Zhang Yuping,
Hu Deyu
Publication year - 2018
Publication title -
biomedical chromatography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 65
eISSN - 1099-0801
pISSN - 0269-3879
DOI - 10.1002/bmc.4301
Subject(s) - indoxacarb , chemistry , enantiomer , enantiopure drug , chromatography , stereochemistry , organic chemistry , agronomy , pesticide , enantioselective synthesis , biology , catalysis
A chiral liquid chromatography–tandem high resolution mass spectroscopic method was developed for the analysis of indoxacarb enantiomers in rice plants, rice hulls and brown rice. Chiral separation of two enantiomers was carried out on a Superchiral S‐OD column maintained at 20°C and eluted with 0.3 mL/min methanol. Samples were extracted by acetonitrile solution with ultrasound and cleansed by dispersive solid‐phase extraction of 50 mg of primary secondary amine and 50 mg of C 18 . This method was successfully used to study the degradation and residues of two enantiomers with enriched S‐ indoxacarb (2.33 S /1 R ) and pure S‐ indoxacarb in rice plants. The half‐lives of R‐ indoxacarb and S‐ indoxacarb were 4.20–4.33 and 3.45–3.57 days in rice plants during the degradation of enriched S‐ indoxacarb in Guizhou and Hunan, respectively, whereas the half‐lives of pure S‐ indoxacarb were 2.68 and 3.69 days in Guizhou and Hunan, respectively. The results indicated that preferential S‐ indoxacarb degradation occurred and that enantiomeric transformation was absent in the total experiment periods of pure S‐ indoxacarb in rice plants. The final residue concentrations of indoxacarb enantiomers in brown rice were significantly less than those in rice plants and rice hulls in the same rice field after applying indoxacarb SC and indoxacarb EC.