Determination of 17 types of phthalates in drinking water by solid-phase extraction coupled with multiple reaction monitoring of gas chromatography-mass spectrometry

Objective: To determine 17 types of phthalic acid esters (PAEs) in drinking water using solid-phase extraction coupled with gas chromatography-mass spectrometry (GC-MS) in multiple reaction monitoring (MRM) mode. Methods: One litre of commercially available bottled water was purified using an HLB solid-phase extraction column, and was eluted with ethyl acetate, dichloromethane and average methanol. Seventeen types of PAEs were detected using a triple quadrupole gas chromatography-mass spectrometer in MRM mode. By optimizing the temperature programming and adjusting the mass spectrometry collision energy, collection efficiency was improved and matrix interference was reduced. The precision and accuracy of this method were assessed by determining the standard curves, detection limits, quantification limits, relative standard deviations (RSD) and average spiked recovery rates for the 17 types of PAEs. Results: The 17 types of PAEs showed good linear relationships between mass concentration and chromatographic peak areas in the range of 0.02 to 1.0 mg/L, with correlation coefficients all greater than 0.999 1. The detection limits ranged from 0.002 9 to 0.009 7 mg/kg, the quantification limits ranged from 0.008 7 to 0.029 1 mg/kg, the RSD ranged from 0.8% to 3.0%, and the average spiked recovery rates ranged from 88.8% to 111.8%. Conclusion: Solid-phase extraction coupled with MRM of GC-MS can better determine low concentrations of PAEs in drinking water.