No abstract

A rapid, simple, and selective analytical method for the simultaneous determination of tebuconazole, trifloxystrobin, and its metabolite trifloxystrobin acid residues in gherkin and soil was developed and validated by gas chromatography coupled with mass spectrometry. The samples were extracted with acetonitrile and cleaned up by dispersive solid-phase extraction with primary secondary amine sorbent. The limit of quantification of the method was 0.05 mg/kg for all three compounds. The method was validated using blank samples spiked at three levels and recoveries ranged from 83.5 to 103.8% with a relative standard deviation of 1.2 to 4.8%. The developed method was validated and applied for the analysis of a degradation study sample. The residues of trifloxystrobin and tebuconazole were found to dissipate following first-order kinetics with half-life ranging between 3.31-3.38 and 3.0-3.04 days, respectively, for two different dosages. Pesticide residues were below the European Union maximum residue level after seven days for trifloxystrobin (0.2 mg/kg) and ten days for tebuconazole (0.05 mg/kg), which suggested the use of this fungicide mixture to be safe to humans. These results can be utilized in formulating the spray schedule and safety evaluation on trifloxystrobin and tebuconazole in gherkin crop.

A multiresidue method was developed and optimized for the quantification of organochlorine pesticides (OCPs) in milk, egg and meat samples. Sample extraction was performed by adopting QuEChERS principle and the extracts were cleaned-up dispersive solid-phase extraction with primary secondary amine after salting out with NaCl and MgSO(4). Analysis was carried out by gas chromatography coupled with electron capture detector and confirmation by gas chromatography-mass spectrometry. The performance of the method was investigated in terms of linearity, accuracy, precision, detection limit and quantification limit (LOQ). Good linearity was obtained, with correlation coefficients (r(2)) higher than 0.992. Mean recoveries were found in the ranges 72%-108%, 74%-101% and 75.27%-104.56% for the milk, egg and meat, respectively, RSD % turned out to range from 0.28% to 10.05%. The method developed was successfully tested on commercial milk, egg, and meat samples from the markets of Tamil Nadu (India), proving to be a useful tool in routine analysis of OCPs for monitoring purposes. None of the compounds of interest were observed above their respective LOQ.

No abstract

A supervised open field trial was conducted to evaluate the dissipation pattern and risk assessment of flubendiamide in gherkin fruits following foliar application of Fame 480 SC at 60 and 120 g a.i. ha(-1). Samples of gherkin fruits were drawn at different time intervals and quantified by HPLC-DAD. The maximum initial deposits of flubendiamide on gherkin were found to be 0.79 and 1.52 mg kg(-1), respectively, at recommended and double the recommended doses. The dissipation pattern of flubendiamide followed a first-order kinetics with half-lives of 1.87 to 2.16 days at 60 and 120 g a.i. ha(-1), respectively. The limit of quantification of flubendiamide and desiodo flubendiamide was observed to be 0.01 mg kg(-1) for gherkin fruit and soil substrates. Theoretical maximum residue contribution (TMRC) for flubendiamide was calculated and found to be well below the maximum permissible intake (MPI) on gherkin fruits. Thus, the application of flubendiamide at the recommended dose on gherkin fruits presents no human health risks and safe to consumers.