title: [Rapid determination of 6 pesticide residues in tomato paste by ultra performance liquid chromatography-tandem mass spectrometry].
abstract: An ultra performance liquid chromatography-tandem mass spectrometric method (UPLC-MS/MS) was established for the simultaneous determination of imidacloprid, carbendazim, thiophanate-methyl, propamocarb, methomyl and dimethomorph residues in tomato paste. The samples were extracted by methanol-water (1: 1, v/v) containing 0.1% (v/v) acetic acid. The separation was performed on a Waters Acquity UPLC system with a BEH C18 column with the gradient elution of methanol and water (containing 10 mmol/L ammonium acetate). The six pesticides were determined in the modes of electrospray positive ionization (ESI+) and multiple reaction monitoring (MRM). The analytes were quantified by matrix-matched standard solution, and the calibration curves showed good linearity within the concentrations of 0.005 to 0.2 mg/L and the correlation coefficients (r) were more than 0.995. The average recoveries of the six pesticides ranged from 66.8% to 102.9% in the three spiked levels of 0.02, 0.05 and 0.2 mg/kg. The relative standard deviations (RSDs) were all less than 15%. The limits of quantification (LOQ, S/N > 10) were 0.02 mg/kg for the all analytes. The results indicate that the method is easier, faster, more sensitive, and suitable for the qualitative and quantitative confirmation of the six pesticide residues from tomato paste.
authors.affiliation: Xinjiang Entry-Exit Inspection and Quarantine Bureau, Urumqi 830063, China.
authors.forename: Min
authors.initials: M
authors.lastname: Su
authors.forename: Shiyu
authors.initials: S
authors.lastname: Li
authors.forename: Fengge
authors.initials: F
authors.lastname: Li
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Gong
authors.forename: Jinhua
authors.initials: J
authors.lastname: Wang
mesh_terms: D001562:Benzimidazoles / Q000032:analysis; D002219:Carbamates / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D007093:Imidazoles / Q000032:analysis; D018551:Solanum lycopersicum; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000032:analysis; D010573:Pesticide Residues / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013875:Thiophanate / Q000032:analysis
chemical_list: D001562:Benzimidazoles; D002219:Carbamates; D007093:Imidazoles; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010573:Pesticide Residues; C082359:imidacloprid; D013875:Thiophanate; C006698:carbendazim