Abstract:

Based on liquid-liquid micro-extraction and acidic methanol derivatization methods from EPA Method 552.3, a gas chromatographic-mass spectrometric (GC-MS) method has been studied for determining haloacetic acid (HAAs) in drinking water using ultrapure water instead of methyl tert-butyl ether (MTBE) as solvent for preparing standard stock solution. The results showed that the peaks of 1,2-dibromo propane (internal standard) and HAAs were separated very well. With the improved method, the recoveries for HAAs (82%-103%) were high at concentrations ranging from 5 to 80 μg/L, the detection limits for dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were 0.72 and 0.44 μg/L. With the improved method, the runtime could be also significantly reduced without compromising the analytical resolutions. It is also demonstrated that the stock standard was stable under storage for 2 months at 4 ℃.

Key words: derivatization , drinking water, haloacetic acids, gas chromatography-mass spectrometry (GC-MS)