三维花状硅酸镁富集-X-射线荧光光谱法测定水中痕量铅锌铜  

Analysis of Trace Pb,Zn and Cu in Water Samples Based on Three-dimensional Flower-Shaped Magnesium Silicate as A Solid Sorbent and X-ray Fluorescence Spectrometry

作　　者：朱万军 翟晓颖 黄人瑶 冯拥军[1] 袁懋[2] 陈旭[1] 杨文胜[1] ZHU Wan-Jun;ZHAI Xiao-Ying;HUANG Ren-Yao;FENG Yong-Jun;YUAN Mao;CHEN Xu;YANG Wen-Sheng(State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology,Beijing 100029,China;China National Environmental Monitoring Centre,Beijing 100012,China)

机构地区：[1]北京化工大学化工资源有效利用国家重点实验室,北京100029 [2]中国环境监测总站,北京100012

出　　处：《分析化学》2018年第9期1386-1392,共7页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(No.21521005)资助~~

摘　　要：X-射线荧光光谱(XRF)分析技术在自动化程度、分析成本和对环境的影响等方面具有明显优势,已被应用于现场快速检测中。但其用于直接测定水体中金属元素时,检出限过高,不能满足检测要求。本研究采用一步混合溶剂热法合成了三维花状结构硅酸镁(Three-dimensional flower-shaped magnesium silicate,3DFMS)纳米材料,以此材料作为吸附剂,选择性富集水中的Pb^(2+)、Zn^(2+)和Cu^(2+),使用便携式能量色散X射线荧光光谱(EDXRF)仪直接分析测定。通过电子显微镜、氮气吸-脱附等对3DFMS的形貌和结构进行表征,并对富集-EDXRF检测中的实验条件进行了优化。优化后的条件为:吸附剂用量为100 mg,水样体积150 m L,p H=4,吸附时间为10 min。在优化条件下,测定Pb^(2+)、Zn^(2+)和Cu^(2+)的线性范围为2.0~240μg/L,检出限分别为0.57、0.69和0.76μg/L。对各金属离子浓度为100μg/L的试样连续测定5次,相对标准偏差为3.8%~5.0%,用于测定实际水样中金属离子的回收率为88.0%~118.0%。本研究建立的3DFMS富集-便携式EDXRF法快速简便,无有机试剂污染,成本低,适用于水体中痕量Pb^(2+)、Zn^(2+)和Cu^(2+)的现场快速检测。X-ray fluorescence(XRF)spectrometry has been widely used for elemental analysis of a wide variety of samples due to its important features such as acceptable speed,economy and nondestructive for samples.Portable energy dispersive X-ray fluorescence spectrometry(EDXRF)is a key technology for on-site determination.However,the poor detection limits make the conventional XRF direct analysis unsatisfactory for liquid samples.Therefore,a proper pre-concentration procedure is needed to decrease the detection limit.In this study,we prepared a kind of three-dimensional flower-shaped magnesium silicate(3DFMS).Due to the high surface area,large pore size and hierarchical nanostructures,3DFMS was employed as a solid sorbent for selective pre-concentration of Pb 2+,Zn 2+and Cu 2+.And then portable EDXRF was applied to directly quantify.The structure and morphology of 3DFMS were characterized by X-ray diffraction,scanning and transmission electron microscopes.The related adsorption and detect conditions have been optimized.Under the optimal conditions(100 mg of adsorbent dose,150 mL of water,pH 4 and 10 min of sorption time),the detection limits(S/N=3)for Pb 2+,Zn 2+and Cu 2+were 0.57,0.69 and 0.76μg/L,respectively.The linear range was 2.0-240μg/L for three elements.Furthermore,the recovery of metal ions in the actual water sample was 88.0%-118.0%.The relative standard deviations for five successive measurements were 3.8%-5.0%for 100μg/L metal ions.The actual water sample was also determined by the proposed method.This present method is rapid,simple,free of organic reagent pollution and low in cost,which is suitable for the rapid determination of trace lead,zinc and copper ions in water.

关 键 词：三维花状硅酸镁 固相萃取 X-射线荧光光谱法 金属离子 现场检测 

分 类 号：O657.34[理学—分析化学] X832[理学—化学]