Simple and rapid determination of phthalates using microextraction by packed sorbent and gas chromatography with mass spectrometry quantification in cold drink and cosmetic samples

A simple and rapid method using microextraction by packed sorbent coupled with gas chromatography and mass spectrometry has been developed for the analysis of five phthalates, namely, diethyl phthalate, benzyl-n-butyl phthalate, dicyclohexyl phthalate, di-n-butyl phthalate, and di-n-propyl phthalate, in cold drink and cosmetic samples. The various parameters that influence the microextraction by packed sorbent performance such as extraction cycle (extract-discard), type and amount of solvent, washing solvent, and pH have been studied. The optimal conditions of microextraction using C-18 as the packed sorbent were 15 extraction cycles with water as washing solvent and 3x10 mu L of ethyl acetate as the eluting solvent. Chromatographic separation was also optimized for injection temperature, flow rate, ion source, interface temperature, column temperature gradient and mass spectrometry was evaluated using the scan and selected ion monitoring data acquisition mode. Satisfactory results were obtained in terms of linearity with R-2 > 0.9992 within the established concentration range. The limit of detection was 0.003-0.015 ng/mL, and the limit of quantification was 0.009-0.049 ng/mL. The recoveries were in the range of 92.35-98.90% for cold drink, 88.23-169.20% for perfume, and 88.90-184.40% for cream. Analysis by microextraction by packed sorbent promises to be a rapid method for the determination of these phthalates in cold drink and cosmetic samples, reducing the amount of sample, solvent, time and cost.