Chemometric optimization of dispersive suspended microextraction followed by gas chromatography–mass spectrometry for the determination of polycyclic aromatic hydrocarbons in natural waters

A dispersive suspended microextraction (DSME) method coupled with gas chromatography–mass spectrometry (GC–MS) was developed and validated for the simultaneous determination of ten polycyclic aromatic hydrocarbons in real water samples. The optimization of the method was achieved with a 27–4 Plackett–Burman design, while the significant factors were optimized using a central composite design (CCD). The parameters that were studied included the sample volume, organic solvent volume, extraction time, restoration time and organic solvent. The optimum experimental conditions for the proposed method comprised 4.3 mL of the water sample, 93 μL of toluene as the extraction solvent, a 104-s extraction time and a 10-min restoration time. The recoveries varied from 70 to 111%. Chrysene was the least recovered compound, while anthracene displayed the highest extraction efficiency. The analytical method (DSME) was shown to be linear (R2 > 0.993) over the studied range of concentrations, exhibiting satisfactory precision (RSD% < 10.6%) and reaching limits of detection between 8 and 46 ng L−1.