流动注射化学发光法测定水体中的N,N-二甲基乙酰胺

Determination of N,N-Dimethylacetamide in Water by Flow Injection Chemiluminescence

摘要: 在酸性条件下,高锰酸钾氧化硫代硫酸钠产生化学发光,N,N-二甲基乙酰胺(DMAC)对该体系的发光强度具有增强作用,基于此建立了测定水体中DMAC的流动注射化学发光法。当硫酸溶液的浓度为1.2 mol·L-1,高锰酸钾溶液、硫代硫酸钠溶液的浓度均为5.0×10-4mol·L-1时,化学发光强度与DMAC的质量浓度在0.20~40.0 mg·L-1范围内呈线性关系,检出限(3S/N)为0.071 mg·L-1。方法用于水体中DMAC含量的测定,加标回收率在97.3%~104%之间,测定值的相对标准偏差(n=7)在1.2%~3.6%之间。

Abstract: A method was proposed for the determination of N,N-dimethylacetamide (DMAC) by flow injection chemiluminescence, based on the fact that DMAC could enhance the chemiluminescence intensity of the KMnO4-Na2S2O3 system in an acidic medium. When the concentrations of H2SO4, KMnO4, Na2S2O3 solutions were 1.2, 5.0×10-4, 5.0×10-4mol·L-1, respectively, a linear relationship was found between the chemiluminescence intensity and the mass concentration of DMAC in the range of 0.20-40.0 mg·L-1, with detection limit (3S/N) of 0.071 mg·L-1. The proposed method was applied to the determination of DMAC in water samples, giving recovery rates obtained by standard addition method in the range of 97.3%-104% and RSDs (n=7) in the range of 1.2%-3.6%.