Determination of nine emerging pesticides at trace level in aqueous samples using fully automated on-line solid phase extraction coupled with liquid chromatography-mass spectrometry

Abstract

On-line solid phase extraction (SPE) coupled to liquid chromatography-mass spectrometry (LC-MS) offers an easy and fast strategy to analyze the organic contaminants in environmental samples with high sensitivity and selectivity. This paper described an in-house designed on-line SPE system and an on-line SPE-LC-MS method for the determination of pesticides at trace levels in water samples. The system was assembled from an eight-position valve, a piston pump, a six-port valve and a C18 SPE column, and significantly reduced analysis time by achieving full automation. Moreover, the use of a large enrichment volume (50 mL) significantly enhanced method sensitivity. Using this on-line SPE system, an on-line SPE-LC-MS method was developed for the determination of nine pesticides at trace levels in lake water and seawater sample. Under optimized conditions, method detection limits (MDLs) were 1.00–10.0 ng L⁻¹.

Keywords:

• on-line SPE
• LC-MS
• pesticides
• water samples

Acknowledgements

We acknowledge Dr. Chang-ping Yu for editing the manuscript. This work was supported by the MEL Visiting Fellowship Program (MELRS1116) and the CAS/SAFEA International Partnership Program for Creative Research Teams (KZCX2-YW-T08). We gratefully acknowledge the Third Institute of Oceanography, State Oceanic Administration for the utilization of the LC-MS.