Determination of heterocyclic aromatic amines in ashes from biomass burning by UHPLC-MS/MS after ultrasound-assisted dispersive solid-liquid microextraction

Abstract

A simple, rapid and efficient methodology was developed for the extraction and determination of heterocyclic aromatic amines (HAAs) in cigarette and forest fire ash samples based on a novel Ultrasound-Assisted Dispersive Solid-liquid Microextraction (UA-DSLME) coupled to polyurethane foam (PUF) mini-column as a clean-up strategy and on-line determination by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The optimal working conditions were found by (i) application of two-level full factorial designs and (ii) implementation of a response surface methodology based on the second-order design as central composite designs. Under optimal experimental conditions, good linearity was obtained for concentrations ranging from 8.3 to 500 ng g−1, with correlation coefficients (r2) varying from 0.995 to 0.999 for all HAAs investigated. The limits of detection and quantification resulted to be between 2.1 and 10.7 ng g−1 and 8.3–16.9 ng g−1, respectively. The recoveries from 92.2 to 100.6% were reached and the relative standard deviations (RSDs) were lower than 9.2%. The developed method was successfully applied to the determination of HAAs in ashes generated by cigarette and forest fire combustion.