Improvement of dispersive liquid-liquid microextraction robustness by performing consecutive extractions: Determination of polycyclic aromatic hydrocarbons in Brazilian sugar cane spirits by GC-MS

Abstract

This paper describes the development of a multiple dispersive liquid-liquid microextraction method for the determination of fifteen polycyclic aromatic hydrocarbons in samples of Brazilian sugar cane spirit (known as cachaça) with separation and detection by GC-MS. The results obtained with the multiple extraction approach were compared to those obtained with the conventional dispersive liquid-liquid microextraction method using the same sample. Sample dilution and solvent volume were optimized using the response surface methodology. The coefficient of determination (R2) for the multiple dispersive liquid-liquid microextraction method varied from 0.9939 to 0.9999. The limits of detection ranged from 0.06 to 1.5 μg L−1 and precision from 12 and 22%. The recovery values obtained with the proposed method ranged from 84 to 116%. The sum of the polycyclic aromatic hydrocarbons concentrations in six samples ranged from 0.65 to 12.2 μg L−1. Multiple dispersive liquid-liquid microextraction was shown to be efficient in relation to compensating the matrix effects due to variations in the sample composition and the extraction parameters showed greater robustness compared to the conventional dispersive liquid-liquid microextraction method, since it simulates an exhaustive extraction.