分光光度法测定废水中多季铵盐浓度

Determination of Concentration of Quaternary Ammonium Salt in Wastewater by Spectrophotometric Method

基于溴百里酚蓝（BTB）在pH值7.5~8.0的碱性介质中与多季铵盐发生离子缔合反应形成稳定的配合物而使BTB褪色的原理,建立了一种BTB标记分光光度法测定废水中多季铵盐浓度的新方法。结果表明,BTB的最大吸收波长为616nm。当BTB溶液浓度为6.0×10-5 mol·L-1时,多季铵盐溶液质量浓度（c）在0.8885~8.885mg·L-1范围内与溶液吸光度降低值（ΔA）呈良好的线性关系,线性方程为ΔA=0.0378＋0.04277c,相关系数为0.9981。将该法用于模拟废水中多季铵盐浓度的测定,加标回收率为96.14%~100.82%,灵敏度为0.04277L·mg-1·cm-1。

According to the reaction of bromothynol blue（BTB）with quaternary ammonium salt（QAS）in alkaline medium（pH=7.5~8.0）,a spectrophotometric method for determination of concentration of QAS in wastewater was established.Results showed that the maximum absorption wavelength of BTB was 616 nm.There was a good linear relationship between mass concentration of QAS（c）and absorbance reduction value（ΔA）,when mass concentration of QAS was in the range from 0.8885 to 8.885mg·L-1 and concentration of BTB was 6.0×10-5 mol·L-1.The equation of standard curve wasΔA=0.0378＋0.04277 c and the correlation coefficient was 0.9981.When the method was used for determination of concentration of QAS in simulated wastewater,the spiked recovery rate was in the range from 96.14% to 100.82%,and the sensitivity was0.04277L·mg-1·cm-1.