采用 2-甲基-2-丁烯衍生化、分散液液萃取和气相色谱-电子捕获检测法测定饮用水中的溴酸盐离子。

Determination of Bromate Ions in Drinking Water by Derivatization with 2-Methyl-2-Butene, Dispersive Liquid-Liquid Extraction and Gas Chromatography-Electron Capture Detection.

机构信息

University of Kashan, Faculty of Chemistry, Department of Analytical Chemistry, Kashan, 8731753153, Iran.

出版信息

J AOAC Int. 2020 Sep 1;103(5):1243-1249. doi: 10.1093/jaoacint/qsaa035.

DOI:10.1093/jaoacint/qsaa035

PMID:33241402

Abstract

BACKGROUND

A simple, rapid, selective and sensitive sample preparation and derivatization method was performed for determination of bromate ions in water by means of dispersive liquid-liquid extraction (DLLE) by gas chromatography-electron capture detection (GC-ECD). This method is based on 2-methyl-2-butene derivatization by bromine produced from bromate ions in acidic medium and extraction by n-hexane.

OBJECTIVE

Derivatizing agent: It is cheap and available and it has high efficiency in reaction with Br2. Simplicity: Preparation and extraction process don't need to any specific equipment and procedure is completely simple and fast. Limit of detection: DL is as low as 0.43 µg/L.

METHODS

Various effective factors on the derivatization and extraction efficiency, such as amount of derivatizing agent, volume of extraction solvent, bromide concentration, volume and concentration of sulfuric acid, type and volume of extracting and dispersing solvent, ionic strength, storage time before extraction and ECD makeup-gas flow rate were investigated.

RESULTS

Under the optimum conditions, the method had a linear calibration curve ranging from 1.0 to 200.0 µg/L for bromate ions with a determination coefficient (R2) of 0.994 and the detection limit was 0.43 µg/L. The recovery percent and relative standard deviation for the determination of 1.0, 5.0 and 50.0 µg/L bromate ion was between 90 and 110%, and 3.0 and 8.0% (n = 3), respectively.

CONCLUSIONS

Finally, the method was successfully applied for the preconcentration and determination of bromate ions in water samples, and satisfactory results were obtained.

HIGHLIGHTS

(1) Fast, easy, accurate and economical innovative analysis of bromate ions in water and wastewater. (2) Determination of inorganic ion by GC-ECD after derivatization (3) Low detection limit (4) Optimization of different method parameters to obtain accurate results based on requirements of international standards, specifically ISO/IEC 17025.

摘要

背景

本文采用气相色谱-电子俘获检测（GC-ECD），通过分散液-液萃取（DLLE）建立了一种简单、快速、选择性和灵敏的水样中溴酸盐离子的测定方法。该方法基于酸性介质中由溴酸盐离子产生的溴与 2-甲基-2-丁烯衍生化，然后用正己烷萃取。

目的

衍生化试剂：廉价易得，与 Br2 反应效率高。简单：制备和萃取过程不需要任何特定的设备，程序完全简单快捷。检测限：DL 低至 0.43 µg/L。

方法

考察了衍生化和萃取效率的各种有效因素，如衍生化剂用量、萃取溶剂体积、溴化物浓度、硫酸体积和浓度、萃取和分散溶剂类型和体积、离子强度、萃取前储存时间和 ECD 载气流量。

结果

在最佳条件下，该方法对溴酸盐离子的线性校准曲线范围为 1.0 至 200.0 µg/L，相关系数（R2）为 0.994，检测限为 0.43 µg/L。对于 1.0、5.0 和 50.0 µg/L 溴酸盐离子的测定，回收率和相对标准偏差分别在 90%至 110%和 3.0%至 8.0%（n=3）之间。