Deep eutectic solvents with low viscosity for the determination of polycyclic aromatic hydrocarbons in environmental water samples by dispersive liquid–liquid microextraction

This paper prepared a series of low-viscosity deep eutectic solvents (DESs) using two terpenoids, menthol and thymol, as hydrogen bonding acceptors and lauryl alcohol as hydrogen bonding donors. 1 H NMR and infrared spectroscopy verified hydrogen bonding between the two components. Furthermore, the developed method used a green DES, which dispersed water samples without dispersant or additional auxiliary equipment. In addition, the low viscosity of this deep eutectic solvent allows high mass transfer efficiency and fast extraction. Based on the above, a sample pretreatment method was developed for hand-shake dispersive liquid–liquid microextraction (DLLME) to determine PAHs in environmental water samples. AGREEpre was used to evaluate the greenness of the method. The results showed that the linear range (0.1–200 µg/L), the detection limits (0.027–0.035 µg/L), and the relative standard deviations (4–7 %) of the developed method are comparable with other methods reported in the literature.