Abstract:

Objective To establish an auto solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry to detect epichlorohydrin（ECH） and n-nitrosodimethylamine（NDMA） in water. Methods Water sample was used 10 mL and added 4 g NaCl. The optimal extraction conditions were achieved with SPME fiber of divinylbenzene/carbon wide range/polydimethylsiloxane（DVB/C-WR/PDMS）. Sample was extracted at 30 ℃ and 500 rpm for 15 min，and desorbed at 250 ℃ for 1 min. Chromatographic separation was performed on a InertCap Pure-Wax chromatographic column（30 m×0.25 mm×0.25 μm），and splitless injection. The target compounds were detected by the multi reaction monitoring（MRM） mode. The quantitation was carried out by the external standard method. Results ECH showed the good linearities in 0.02-0.80 μg/L，NDMA showed the good linearities in 0.05-2.00 μg/L， and the correlation coefficients（r） were >0.999 3. The limits of detection（LODs，S/N=3） for ECH and NDMA were 0.008 and 0.02 μg/L. The average recoveries ranged from 89.1% to 104.0%，and relative standard deviation（RSD） were in the range of 6.1%-9.7% with the concentration levels of low，medium and high. Conclusion This method is applicable for the detection of ECH and NDMA in water，and the method sensitivity meets the requirements of various water quality monitoring standards，which is convenient， efficient，and environmentally friendly.

Key words: Water, Solid phase microextraction, Epichlorohydrin, N-nitrosodimethylamine, Gas chromatography-triple quadrupole mass spectrometry, Environmentally benign chemistry