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

Baby food is made specifically for babies between the ages of 4/6 months up to 2 years, 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 5 min on the vortex mixer and for 6 min in an ultrasonic bath to 100 W for favoring the solvent dispersion and the determinant extraction, is centrifuged at 4000 rpm for 30 min: 1 μL 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 0.5–2.9 ng/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.