Analytical Method Validation for Determining Organophosphorus Pesticides in Baby Foods by a Modified Liquid-Liquid Microextraction Method and Gas Chromatography-Ion Trap/Mass Spectrometry Analysis

摘要

Baby food is made specifically for babies between the ages of 4/6months up to 2years, and it comes in multiple varieties and tastes. This paper proposes a protocol for a rapid and reliable determination of 19 organophosphorus pesticides (OPs) by means of a method based on ultrasound-vortex-assisted liquid-liquid microextraction coupled with a gas chromatography-ion trap mass spectrometry (UVALLME-GC-IT/MS). The method development starts from the extraction solvent evaluation, i.e., n-heptane; the solution, held for 5min on the vortex mixer and for 6min in an ultrasonic bath to 100W for favoring the solvent dispersion and the determinant extraction, is centrifuged at 4000rpm for 30min: 1L of the organic extract is injected into the GC-IT/MS. All the analytical parameters investigated are deeply discussed; LODs/LOQs (0.2-1.3 and 0.5-2.9ng/g) and recoveries (81-109%) are compared with other papers dealing the determination of OPs in baby food matrix. The whole method has been applied to real commercial freeze-dried and soft baby food samples: the results do not show any significant contaminant values.