DERIVATIZATION OF SMALL ACIDS TO ENHANCE SENSITIVITY IN GAS CHROMATOGRAPHY MASS SPECTROMETRY AND GAS CHROMATOGRAPHY VACUUM ULTRAVIOLET SPECTROSCOPY
Abstract
Disinfection by-products (DBPs) are a significant concern in drinking water quality. Haloacetic acids, which are generated from disinfection processes, are one of the major groups in disinfection by-products. Because they induce potential harmful effects for human health, the US government has already established regulations to control the levels of haloacetic acids in drinking water. In order to control the presence of haloacetic acids in drinking water and monitor other potential harmful compounds, an appropriate analytical method is needed. In this study, a gas chromatography (GC) method was developed for detecting haloacetic acids in water. Three different derivatization reagents were compared for sensitivity enhancement in conjunction with mass spectrometry (MS) and vacuum ultraviolet (VUV) detection. A model study was first performed using acetic acid and then the study was extended to haloacetic acids. The sensitivity of GC-MS and GC- VUV had been increased after the derivatization. However, it also had many shortcomings and challenges that needed to be overcome: (1) the efficiency of derivatization was low; (2) the benzyl alcohol derivatization caused many side reactions in complex samples and generated high intensities of interference noises. Further study will need to modify the GC-MS and GC- VUV methods, especially for the detection of brominated trihaloacetic acids.