水中N,N-二甲基甲酰胺的流动注射-化学发光法测定

摘要

Based on the fact that the chemiluminescence of the KMnO4-Na2SO3system can be remarkably enhanced by N,N-dimethylformamide(DMF)in acidic media and the lumi-nous intensity is linear correlation to N,N-dimethylformamide under certain concentration range,so a method of FI-CL determination of DMF was proposed.Under the optimum con-dition,the liner range for DMF was 0.8mg/L ~100.0mg/L,and the detection limit was 0.418mg/L.The relative standard deviation(RSD) was 1.30% for the eleven-time consec-utive determination of 55.0mg/L DMF.The proposed method has been applied successfully to the determination of DMF in water samples with recoveries in the range of 96% ~104%. The luminescence mechanism was discussed by analyzing the chemiluminescence kinetics curve and the UV absorption spectrum.%建立了流动注射-化学发光法测定N,N-二甲基甲酰胺(DMF)的新方法.在酸性条件下,高锰酸钾氧化亚硫酸钠产生化学发光,DMF对该体系的发光强度具有增强作用,化学发光的强度与DMF的质量浓度在0.8~100.0mg/L范围内呈良好的线性关系.在优化的实验条件下,用流动注射-化学发光法测定 DMF,检出限为0.418mg/L;对55.0mg/L DMF进行连续11次平行测定,相对标准偏差(RSD)为1.30%;该方法用于水体中DMF含量的测定,加标回收率在96% ~104%之间,结果令人满意.通过对化学发光动力学曲线及紫外吸收光谱的分析,探讨了发光机理.