Aqueous Two-phase Extraction Based on Deep Eutectic Solvents Coupled with UPLC for the Analysis of Heterocyclic Aromatic Amines in Urine of Smokers

To assess the exposure to heterocyclic aromatic amines(HAAs) from tobacco smoke, a novel method, an aqueous two-phase system based on deep eutectic solvent(DES-APTS) followed by UPLC, was described to analyze five HAAs(IQ, IQ[4,5-b], Harman, Norharman, Phe-P-1) from the urine samples of smokers. Seven kinds of choline chloride(ChCl)-based DESs had been synthesized and characterized by 1H NMR and FTIR spectra. The significant parameters affecting the extraction efficiency of HAAs in the DES-ATPS procedure were systematically investigated. Under optimal extraction conditions, the recoveries for the target HAAs ranged from 81.9% to 106.2%. The obtained intra- and inter -day relative standard deviations(RSDs) were less than 2.9% and 3.2%, respectively. The detection limits(LODs) and quantification limits(LOQs) were obtained in ranges of 0.020-0.097 ng/g and 0.19-0.39 ng/g, respectively. The developed method of DES-ATPS, with its simplicity, good environmentfriendliness and low-cost per sample, could be a promising alternative technique for rapidly extracting and quantifying HAAs from urine samples, and displayed great development potential in the field of the detection in biological samples.