顺序进样流动注射光度法测定水中氨氮

将顺序进样与流动注射分光光度法相结合,研发了氨氮自动在线检测仪,用于测定水中氨氮质量浓度.实验结果表明:当进样量为0.39 mL、显色剂体积为0.33 mL、停留时间为5 min、载流液流量为2.0 mL/min时,氨氮质量浓度p与吸光度A在氨氮质量浓度为0～ 15.00 mg/L的范围内呈良好的线性关系,标准工作曲线方程为A=0.01929+ 0.2362,相关系数为0.9993(n=11);检出限为0.020 mg/L;相对标准偏差为0.50％～2.38％;实际水样的加标回收率为94.5％～106.0％.

Determination of Ammonia in Water by Sequential Sampling and Flow Injection Spectrophotometry

With the combination of sequential sampling and flow injection spectrophotometry,the ammonia automatic on-line monitor was developed for determination of ammonia mass concentration in water.The experimental results show that:When the injection volume is 0.39 mL,the chromogenic reagent volume is 0.33 mL,the residence time is 5 min and the carrier liquid flow is 2.0 mL/min,the ammonia mass concentration shows a good linear relationship with the absorbance A at a range of 0-15.00 mg/L,the standard curve equation is A=0.019 2ρ+ 0.236 2 with correlation coefficient of 0.999 3(n=11);The detection limit is 0.020 mg/L;the relative standard deviation is 0.50%-2.38%;The recovery of standard addition is 94.5%-106.0%.