Application of chemometric assisted dispersive liquid–liquid microextraction to the determination of personal care products in natural waters

A rapid and simple method for the determination of two phthalates and five polycyclic musks in water samples using dispersive liquid–liquid microextraction (DLLME) mated to chemometrics and coupled to GC–MS was developed. Volume of extraction (CCl4) and disperser solvent (MeOH), pH, ionic strength, extraction time, centrifugation time as well as centrifugation speed were optimized in a 27–4 Plackett–Burman design. The obtained significant factors were optimized by using a central composite design (CCD) and the quadratic model between the dependent and the independent variables was built. The optimum experimental conditions of the proposed method were: 250 μL carbon tetrachloride, 0.62 mL methanol, 7.5 min centrifugation time, natural pH containing 0% (w/v) NaCl, while keeping centrifugation speed fixed at 4000 rpm.The calculated calibration curves gave high-level linearity for all target analytes with correlation coefficients ranging between 0.9970 and 0.9992. The repeatability and reproducibility of the proposed method, expressed as relative standard deviation, varied between 2.6% to 9.7% and 5.7% to 12.2%, respectively. The obtained LOD values were in the range of 8–63 ng L−1.