The Research On Detection Method Of Haloacetic Acids In Water

Haloacetic acids (HAAs) are a group of disinfection by-products formed in chlorinatedwater. Due to their potential health effects, the research of HAAs has been more and moreattentived. The thesis have systematically studied pretreatment procedure and analyticalmethod for nine HAAs (MCAA、DCAA、TCAA、MBAA、DBAA、TBAA、BCAA、DBCAA、DCBAA) in water sample. Gas chromatography and gas chromatography/mass spectrometry(GC/MS) analytical method were developed for determining HAAs. The study includes thefollowing five parts:Part1: This paper summaried the formation, nature, toxicity, degradation anddetermination technology of HAAs as well as compared the existing standards and monitoringmethod.Part2: To optimize the pretreatment conditions and modify the gas chromatographicprogram by studying nine HAAs. Internal standard is1,2,3–trichloropropane. NaCl is addedto increase the ionic strength of the aqueous phase.10%methanol i n sulfuric acid is used asderivative reagent. The heating temperature is50℃. Reaction time is2h. The studies of theextracts stability showed that the HAAs recoveries did not change significantly in any of thesamples when stored at-10℃,4℃for20days, however it would significantly reduce after20days under room temperature.Part3: The analytical method of9HAAs in water by GC-ECD was found with internalstandard quantitative determination. The linear relations were good between1μg/L and200μg/L. The results demonstrated that the method detection limits for9HAAs were less than1ug/L. The recoveries were within82.4%~112%, the RSD of precisions were1.0%～7.7%.The recoveries of surrogate were86.6%～98.7%.Part4: The analytical method of9HAAs in water by GC-MS (EI) was found. Theresults demonstrated that the method detection limits for9HAAs were higher than those ofGC-ECD. The linear relations were good between10μg/L and200μg/L. The recoveries werewithin93.9%~113%,the RSD of precisions were0.98%～7.66%. The recoveries of surrogatewere84.5%～103%.Part5: The study of several typical water in Qingdao showed that the concentrations ofHAAs in drinking water were1.23~11.2μg/L, which can meet the GB5749-2006; Theconcentrations of HAAs in waste water after chlorination disinfection were30times higherthan that after ultraviolet disinfection.