title: Simultaneous detection and degradation patterns of kresoxim-methyl and trifloxystrobin residues in citrus fruits by HPLC combined with QuEChERS.
abstract: This study aimed to investigate the residues, kinetics and dissipation patterns of kresoxim-methyl, (E)-methoxyimino[α-(o-tolyloxy)-o-tolyl]acetate, and trifloxystrobin, methyl(E)-methoxyimino-{(E)-α[1-(α,α,α-trifluoro-m-tolyl)ethylideneaminooxy]-o-tolyl}acetate". A simple and sensitive liquid chromatography-ultraviolet detection (LC-UV) method combined with the 'Quick Easy Cheap Effective Rugged and Safe' (QuEChERS) protocol was developed to quantify the levels of kresoxim-methyl and trifloxystrobin residues in citrus. More than 97% of the kresoxim-methyl and trifloxystrobin deposists gradually dissipated from the citrus peels within 15 days. The half-lives of kresoxim-methyl and trifloxystrobin in the peels were in the ranges of 2.63-2.66 d and 3.12-3.15 d, respectively, and the pattern of decline in the peels followed first-order kinetics. The kresoxim-methyl and trifloxystrobin residues in the pulp dissipated below the detectable level of 0.01 mg kg(-1) after 9 days. Kresoxim-methyl and trifloxystrobin were easily decomposed (T1/2 < 30 d), and the observed dissipation patterns could support the application of these two fungicides in the postharvest storage of citrus fruits.
authors: College of Life Science, China Jiliang University, Hangzhou, China.
authors: Jie
authors: J
authors: Zhu
authors: Xian J
authors: XJ
authors: Dai
authors: Jian J
authors: JJ
authors: Fang
authors: Hua M
authors: HM
authors: Zhu
mesh_terms: D000085:Acetates / Q000032:analysis* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002957:Citrus / Q000737:chemistry*; D005506:Food Contamination / Q000032:analysis; D005638:Fruit / Q000737:chemistry; D005659:Fungicides, Industrial / Q000737:chemistry* / Q000302:isolation & purification; D007097:Imines / Q000032:analysis* / Q000302:isolation & purification; D007700:Kinetics; D008689:Methacrylates / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D010573:Pesticide Residues / Q000737:chemistry* / Q000302:isolation & purification; D010648:Phenylacetates / Q000737:chemistry* / Q000302:isolation & purification; D052616:Solid Phase Extraction / Q000379:methods*; D000073739:Strobilurins
chemical_list: D000085:Acetates; D005659:Fungicides, Industrial; D007097:Imines; D008689:Methacrylates; D010573:Pesticide Residues; D010648:Phenylacetates; D000073739:Strobilurins; C469328:kresoxim-methyl; C467051:trifloxystrobin