title: Systematic optimisation of coupled microwave-assisted extraction-solid phase extraction for the determination of pesticides in infant milk formula via LC-MS/MS.
abstract: An extraction method consisting of both microwave-assisted extraction (MAE) and solid phase extraction (SPE) was developed to extract pesticides of different polarities in infant milk formula. An experimental central face composite design was established to evaluate the effects of several MAE variables simultaneously such as temperature and pH of extractant. With Derringer desirability function, all pesticides were optimally extracted at 102 °C within 20 min with 4.56 mL of extractant consisting of 0.1% of water in methanol at pH 12. Extraction efficiency was subsequently analysed with LC-MS/MS. The extraction recoveries ranging from 72% to 111% were obtained for all pesticides at fortification level of 5-100 μg kg(-1) with relative standard deviations (RSDs) of less than 8%. Compared with Soxhlet/SPE, the MAE/SPE method utilised less solvent and higher recoveries were achieved with a shorter extraction time.
authors: Department of Chemistry, National University of Singapore, Singapore, Republic of Singapore.
authors: Guihua
authors: G
authors: Fang
authors: Hiu Fung
authors: HF
authors: Lau
authors: Wai Siang
authors: WS
authors: Law
authors: Sam Fong Yau
authors: SF
authors: Li
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D041943:Infant Formula / Q000737:chemistry*; D008872:Microwaves; D010575:Pesticides / Q000032:analysis* / Q000302:isolation & purification*; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D010575:Pesticides