Portable cold-assisted head-space solid-phase microextraction coupled with GC-MS/MS for sensitive determination of...

A cold-assisted headspace solid-phase microextraction (CA-HS-SPME) method combined with gas chromatography-mass spectrometry (GC-MS) was developed for the determination of eight polychlorinated naphthalene (PCN) congeners in water sample. In the CA-HS-SPME setup, frozen gel served as the refrigerant and copper tube as the thermal conductor to cool the polydimethylsiloxane (PDMS) fiber during extraction, thereby enhancing extraction efficiency. The main experimental variables affecting the extraction performance, including temperature, extraction time, and salt concentration, were systematically optimized. Under the optimized conditions, the method exhibited good linearity over the range of 0.1/0.5/1-500 pg/mL, with the correlation coefficient (r) values ≥ 0.9962. The enrichment factors for the PCNs ranged from 955 to 4299, while the limits of detection and quantification were 0.02-0.28 pg/mL and 0.07-0.92 pg/mL, respectively. The intra-day and inter-day precisions (n = 6), expressed as the relative standard deviations, were 10.8%-16.3% and 12.2%-17.8%, respectively. The recoveries obtained from fortified water samples ranged from 90.7% to 117.8%. The proposed method is sensitive, simple, solvent-free, and provides an effective approach for the determination of trace PCNs in water.