RESUMO
A method of metal organic nanotubes-based dispersive solid phase extraction-gas chromatography-tandem mass spectrometry was developed for sensitive analysis of polychlorinated biphenyls in environmental water samples.Related important factors influencing enrichment efficiency, such as ionic strength, extraction time and amount of adsorbent, were investigated.Response surface methodology was used to optimize these factors in detail.Under the optimal conditions such as 4.92% (w/V) NaCl, 4.5 min of extraction time, 62.5 mg of adsorbent, and n-hexane as desorption solvent, wide linearity (2-1000 ng/L or 5-1000 ng/L), and low limits of detection (0.26-0.82 ng/L) were achieved.The intra-day and inter-day relative standard deviations were 0.8%-5.5% (200 ng/L, n=6)and 2.7%-7.4% (200 ng/L, n=6), respectively.Finally, this method was successfully applied to the sensitive analysis of 6 kinds of PCBs in environmental water samples, with satisfactory recoveries of 78.9%-113.3%.