| Comparing the three different methods of determination of acetaldehyde, acrolein and acrylonitrile in water, the results show that the instruments of large volume injection method is simple, but manual injection is time-consuming and costly, and this method has low sensitivity and bad precision. The large volume injection method may shorten the lifetime of column and detector by injecting water sample directly into gas chromatograph. Auto-headspace method is accurate, stable and has wide linear range, good correlations and good precision, which is suitable for determination of high-concentration water sample. With low detection limit and high recovery, purge and trap GC method is simple and is suitable for determination of low-concentration water samples. And it has symmetric shape of peaks. Auto-headspace method and purge and trap-GC method are highly automated for determination of a large number of water samples. |
