Chemometrics-assisted-liquid phase microextraction based on deep eutectic solvents followed by gas chromatography for determination of polycyclic aromatic hydrocarbons in aqueous and juice samples

In the present study, an optimized liquid-phase microextraction technique based on the deep eutectic solvent (LPME-DES) followed by gas chromatography-flame ionization detector (GC-FID) is developed to determine 13 carcinogenic polycyclic aromatic hydrocarbons (PAHs) in water and juice samples. In this regard, central composite design (CCD) was used to design, multiple linear regression (MLR) to model, and Nelder-Mead simplex optimization to optimize the effective LPME-DES factors. The optimum values for DES volume, temperature, extraction time, and salt amount were 112 mu L, 72 degrees C, 9.14 min, and 2.5% (w/v), respectively. Afterward, multivariate calibration based on partial least squares regression (PLSR) was developed in the concentration range of (0.2-70 ng mL-1) and its performance in terms of sensitivity (SEN), analytical sensitivity (gamma), limit of detection (LOD), limit of quantitation (LOQ), and root mean square error of prediction (RMSEP) was compared with classical univariate calibration. Finally, to test the applicability of the proposed method in real samples, sea/ well waters and orange/apple juices were analyzed at 10 and 30 ng mL-1 concentration levels. The relative recoveries were obtained in the range of 66.5%-130.4% for 10 ng mL-1 and 65.4%-124.5% for 30 ng mL-1. In conclusion, the developed method based on LPME-DES combined with GC-FID and chemometric techniques can be used as an efficient method for determining PAHs in real matrices.