水中苯胺类化合物分析的难点

Difficulties in the Determination of Aniline Compounds in Water

结合实验研究了水中苯胺类化合物的测定难点和影响因素,包括样品保存和水样中悬浮物的影响。苯胺类化合物易被氧化,样品不易保存且受悬浮物的影响。研究结果表明:样品中未加入抗氧化剂进行保存时,部分苯胺类化合物迅速降解;当样品中加入80 mg/L硫代硫酸钠进行保存时,部分苯胺类化合物的保存时间可以延迟2~3 d后降解。样品中悬浮物对联苯胺萃取影响较大,回收率偏低,可以通过调节样品pH至酸性后过滤,再将滤液调至中性后进行萃取,回收率明显提高。笔者同时讨论了消除与补偿基质干扰的方法,包括色谱分离条件和检测器条件的选择、优化,内标法、空白基质匹配标准校正法和工作曲线法等定量方法的选择。

The difficulties and influencing factors in the determination of aniline compounds in water were studied with experiment,including the impact of sample preservation and suspended solids in water sample.Aniline compounds are easy to be oxidized,the sample is not easy to be preserved and is affected by suspended solids.The results showed that some aniline compounds were rapidly degraded when no antioxidant was added to the samples for preservation;When 80 mg/L sodium thiosulfate was added to the sample for preservation,the preservation time of some aniline compounds could be delayed for 2-3 days.The suspended solids in the sample had a great influence on the extraction of benzidine,and the recovery was relatively low.It could be filtered by adjusting the pH of the sample to acidity,and then the filtrate was adjusted to neutral for extraction,and the recovery was significantly improved.The methods of eliminating and compensating matrix interference were discussed,including the selection and optimization of chromatographic separation conditions and detector conditions,the selection of quantitative methods such as internal standard method,blank matrix matching standard correction method and working curve method.