Enhancing the performance of membrane introduction mass spectrometry by organic carrier and liquid chromatographic separation

A method of membrane introduction mass spectrometry with liquid chromatographic separation (LC/MIMS) for the analysis of volatile organic compounds (VOCs) in water has been developed. The method not only inherited all the advantages of membrane introduction mass spectrometry by flow-injection analysis (FIA/MIMS), but also expanded the application of MIMS to the determination of compounds with identical quantitation ions. Because the quantitation by LC/MIMS is based on two-dimensional identification (retention time (tr) and mass-to-charge ratio (mz)), it provides a tangible approach to the analysis of VOCs in complex aqueous samples. In this work, a C18 column and a mobile phase (methanol/water) were used for chromatographic separation. A mixture of eighteen VOCs was determined within 28 min. The method has linear dynamic ranges of 3–4 orders of magnitude and sub-ppb-level detection limits. In comparison with the EPA method 524.2 (a purge-and-trap GC/MS method), it requires less analysis time and no sample pretreatment.