Affiliation:
1. Agricultural University of Athens, Laboratory of Pesticide Science, Votanikos, 118 55 Athens, Greece
2. Benaki Phytopathological Institute, Pesticide Residues Laboratory, Kifissia 14561, Greece
3. Agricultural University of Athens, Laboratory of Pesticide Science, Votanikos, 188 55 Athens, Greece
Abstract
Abstract
A simple and sensitive method using high-performance liquid chromatography/mass spectrometry (LC/MS) was developed and validated for simultaneous determination of 5 benzoylurea insecticidesdiflubenzuron, triflumuron, teflubenzuron, lufenuron, and flufenoxuronin tomatoes. Residues were successfully separated on a C18 column by methanolwater isocratic elution. Detection was carried out by an ultraviolet diode array detector (UV-DAD) coupled with a quadrupole mass spectrometer, using atmospheric pressure chemical ionization (APCI) in negative-ion mode. The main ions were the deprotonated molecules [MH]<sup/> for triflumuron, and the anions formed by elimination of hydrofluoric acid [MHHF]<sup/> for diflubenzuron and flufenoxuron, and [M2HHF] for lufenuron and teflubenzuron. The calibration plots were linear for both detectors over the range 0.05 to 10 g/mL, and the method presented good quality parameters. The limits of detection for standard solutions were 0.0080.01 mg/L (equivalent to 0.080.1 ng injected) for both detectors, and the limits of quantification (LOQs) were approximately 10 times lower than national maximum residue levels (MRLs). Depending on the compound and the detector, the LOQ values ranged from 0.2 to 0.4 ng injected. The optimum LC-UV-DAD/APCI-MS conditions were applied to the analysis of benzoylureas in tomatoes. The obtained recoveries from fortified tomato samples (50 g), extracted with ethyl acetate and purified by solid-phase extraction on silica sorbent, were 88100 and 92.9105 for the UV-DAD and MS detectors, respectively, with precision values (relative standard deviations) of 2.911 and 3.714, respectively. The method was applied to 12 tomato samples from local markets, and diflubenzuron and lufenuron were detected in only one sample at concentrations lower than the MRLs. The results indicate that the developed LC/MS method is accurate, precise, and sensitive for quantitative and qualitative analysis at low levels of benzoylureas required by legislation.
Publisher
Oxford University Press (OUP)
Subject
Pharmacology,Agronomy and Crop Science,Environmental Chemistry,Food Science,Analytical Chemistry
Cited by
10 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献