QuEChERS-based method for the multiresidue analysis of pesticides in beeswax by LC-MS/MS and GC×GC-TOF.
The validation of an analytical procedure for the determination of pesticide residues in beeswax, an interesting matrix for environmental pollution monitoring, is presented. Using the QuEChERS template, the impacts of wax particle size, sample amount, and cleanup procedure (water addition, dispersive solid phase extraction, freeze-out, and combinations thereof) on extraction yield and coextractive load were studied. Sample preparation through liquid-liquid partitioning between acetonitrile and melted wax (∼80 °C), followed by freeze-out and primary-secondary amine dispersive cleanup, was performed on incurred and pesticide-free samples for 51 residues. Determinations were made through LC-MS/MS and GC×GC-TOF, and the whole procedure was validated. Matrix effects were evaluated, with recoveries between 70 and 120% and RSDs below 20% in almost all cases. LC-MS/MS LOQs ranged from 0.01 to 0.1 mg/kg for most pesticides, but for GC-amenable pesticides, GC×GC-TOF sensitivity was lower (0.1-0.2 mg/kg). This methodology can be applied for routine analysis of pesticide residues in beeswax.
Cátedra de Farmacognosia y Productos Naturales, Facultad de Quı́mica , Universidad de la República , Gral. Flores 2124, CP11800 Montevideo, Uruguay.
Silvina
S
Niell
Verónica
V
Cesio
Julia
J
Hepperle
Daniela
D
Doerk
Larissa
L
Kirsch
Diana
D
Kolberg
Ellen
E
Scherbaum
Michelangelo
M
Anastassiades
Horacio
H
Heinzen
D002853:Chromatography, Liquid; D008401:Gas Chromatography-Mass Spectrometry; D010573:Pesticide Residues / Q000032:analysis* / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry; D014885:Waxes / Q000737:chemistry*
D010573:Pesticide Residues; D014885:Waxes; C038228:beeswax