Combination of microwave heating extraction and dispersive liquid-liquid microextraction for the determination of nitrosoamines in foods using gas-liquid chromatography with a mass-spectrometric detector

Resumo

A method has been developed for the determination of trace amounts of seven nitrosoamines (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosopyrrolidine, N-nitrosodipropylamine, N-nitrosopiperidine, and N-nitrosodibutylamine) in food using gas-liquid chromatography with a mass-spectrometric detector. The optimum chromatographic conditions were selected: a DB-5MS column, temperature ramp rate 10 K/min from 40 to 250°C, carrier gas flow rate 1 mL/min. Conditions of the extraction of nitrosoamines from samples using microwave heating extraction followed by dispersive liquid-liquid microextraction, ensuring sufficient preconcentration and additional purification of the extract, have been optimized. The linearity ranges for nitrosoamines were (0.5–2.5)–25 µg/kg; the limits of detection were 0.1–0.5 µg/kg (signal-tonoise ratio 3). The method has been applied to the analysis of samples of sausage, smoked chicken meat, and smoked pork. The time of analysis is 1.5–2 h, the relative standard deviation of the results of analysis does not exceed 10%.