An inline ion-exchange system in a chemiluminescence-based analyzer for direct analysis of N-nitrosamines in treated wastewater
An inline ion-exchange system in a chemiluminescence-based analyzer for direct analysis of N-nitrosamines in treated wastewater
复制标题
DOI：
10.1016/j.chroma.2018.04.030
复制
发表时间：
2018-06-08
影响因子：
4.1
通讯作者：
Fujioka, Takahiro
中科院分区：
文献类型：
--
作者：
Kodamatani, Hitoshi;Roback, Shannon L.;Fujioka, Takahiro
为了减少天然水和处理后废水中背景成分的影响，开发了一种基于离子交换的在线前处理系统，以实现对N-亚硝胺的快速、可靠和灵敏的分析。将前处理系统(阴离子交换模块)与高效液相色谱仪、光化学反应器(PR)和化学发光检测器(PLCPR-CL)相结合，可以在ng/L水平上分析4种亲水性N-亚硝胺。与其他传统的N-亚硝胺分析技术不同，该系统不需要对水样进行预浓缩，也不需要使用氚代物。AEM在高效液相分离后将洗脱液中的阴离子转化为氢氧化物离子，并提高洗脱液的pH，从而允许后续的光化学反应，否则这些反应是通过额外的基础化学剂量泵进行pH调节来实现的。AEM还从样品中去除了阴离子干扰化合物(如硝酸盐)，从而改进了处理后废水中的N-亚硝胺分析。对AEM和PR的操作条件进行了优化，以获得灵敏稳定的分析性能。结果表明，在优化体系下，N-亚硝基二甲胺、N-亚硝基吗啉、N-亚硝基甲基乙胺和N-亚硝基吡咯烷的最低报告浓度分别为0.42、0.54、0.58和1.4 ng/L。将改进后的分析方法与传统的基于气相色谱-质谱仪离子陷阱检测器的分析方法进行了比较，验证了改进的分析方法的有效性。这些结果表明，配备在线AEM的高效液相色谱-PR-CL可以作为一种快速分析技术用于各种水基质中N-亚硝胺的测定。(C)2018爱思唯尔B.V.保留所有权利。
A newly developed, ion exchange-based inline pretreatment system was used to mitigate the effect of background constituents in natural water and treated wastewater to achieve rapid, reliable, and sensitive analysis of N-nitrosamines. The pretreatment system (anion exchange module, AEM) was incorporated into a high-performance liquid chromatograph (HPLC) coupled with a photochemical reactor (PR) and chemiluminescence (CL) detector (HPLC-PR-CL), which can analyze four hydrophilic N-nitrosamines at ng/L levels. This system requires no pre-concentration of the water sample nor the use of deuterated surrogates, unlike other conventional N-nitrosamine analytical techniques. The AEM converted anions in the eluent to hydroxide ions after HPLC separation and increased eluent pH, allowing for the subsequent photochemical reactions, which are otherwise achieved by pH conditioning with an additional dosing pump of basic chemical. The AEM also removed anionic interfering compounds (e.g. nitrate) from the samples, allowing for improved N-nitrosamine analysis in treated wastewater. The operating conditions of the AEM and PR were optimized to obtain sensitive and stable analytical performance. As a result, the lowest-concentration minimum reporting levels of N-nitrosodimethylamine, N-nitrosomorpholine, N-nitrosomethylethylamine, and N- nitrosopyrrolidine using the optimized system were 0.42, 0.54, 0.58, and 1.4 ng/L, respectively. The improved analytical method was validated by comparing the results with a conventional method based on gas chromatography coupled with a mass spectrometric ion trap detector. These results indicated that HPLC-PR-CL equipped with an inline AEM can be competitively applied as a rapid analytical technique for the determination of N-nitrosamines in various water matrices. (C) 2018 Elsevier B.V. All rights reserved.