污水中溶解游离氨基酸和结合氨基酸测定方法研究

采用邻苯二甲醛作为柱前衍生化试剂，结合反相高效液相色谱，对污水中溶解游离氨基酸（dissolvedfreeami．nOacid，DFAA）进行定性和定量分析，探讨了污水样品有无前处理对DFAA分析的影响，并采用气相酸水解方法对污水中总溶解氨基酸（dissolvedtotalaminoacid，DTAA）进行了分析。结果表明，污水经过pH调节和N，流清洗后，可以明显去除氨和挥发性胺的干扰，色谱峰更加清晰；前处理后的水样经RP—HPLC分析，能够快速检测出14种氨基酸，各氨基酸在一定线性范围内呈现良好的线性关系，相应的线性相关系数（R^2）均大于0．99，加标回收率为92％～102％。污水处理厂进水和出水中氨基酸主要以溶解结合氨基酸（dissolvedcombinedaminoacid，DCAA）为主，与进水相比，出水中DFAA含量减少了0．22μmol／L，DTAA由5．68μmol／L降至3．08μmol／L。

Study on methods for determination of dissolved free and combined amino acids in unconcentrated wastewater

In this study, a reversed-phase high performance liquid chromatograph （RP-HPLC） combined with precolumn O-phthalaldehyde derivatization and fluorescence detection was set up for the qualitatively and quantitatively analysis of dissolved free amino acids （DFAA） in unconcentrated wastewaters. The effects on ana- lyzing DFAA were investigated in uneoncentrated wastewaters with and without pretreatment and the rapid vapor- phase hydrolysis method was used for dissolved total amino acid （DTAA） analysis. The results showed that the interference caused by ammonia and volatile amines could be eliminated to make chromatographic peaks clearer after adjusting pH and purging with N2 gas. 14 amino acids could be determined using RP-HPLC for the samples with pretreatment. Each amino acid showed good linearity in a certain range with the correlation coefficient （R2） more than 0.99. The spiked recoveries were from 92% to 102%. The dissolved combined amino acid （DCAA） took a large percentage of DTAA in the influent and effluent at the wastewater treatment plant. The DFAA con- centration in the effluent decreased by 0.22 μmol/L compared with that in the influent while the DTAA concen- tration decreased from 5.68 in the influent to 3.08 μmol/L in the effluent.