鸡蛋膜固相萃取-石墨炉原子吸收光谱法测定水样中的微量铅  

Solid Phase Extraction of Lead Using Eggshell Membrane in Water Samples Prior to Graphite Furnace Atomic Absorption Spectrometric Determination

作　　者：刘金[1] 彭元[1] 陈红梅[1] 程先忠[1] 

机构地区：[1]武汉工业学院化学与环境工程学院,湖北武汉430023

出　　处：《岩矿测试》2012年第5期872-876,共5页Rock and Mineral Analysis

基　　金：湖北省自然科学基金重点项目(2008CDA100)

摘　　要：鸡蛋膜是由蛋白质组成的一种纤维状的生物膜。本研究利用扫描电镜和红外光谱对鸡蛋膜的结构进行分析表征,证实其具有网状结构,表面存在着—OH、—COOH、—NH2等官能团,能与一些金属离子产生吸附和交换作用。在pH=6的条件下,用蛋膜作吸附剂分离富集水样中的微量铅,5 mL 3%的硝酸进行洗脱,然后采用石墨炉原子吸收光谱法进行测定。实验中对吸附分离介质、溶液流速、蛋膜用量、洗脱剂浓度及共存离子的影响等条件进行了优化和讨论。在最佳的实验条件下,蛋膜对铅的富集倍数为30,方法检出限(3σ)为0.017 ng/mL,相对标准偏差(RSD,n=11)为3.45%,加标回收率为96.0%～104.2%。与现行的分离富集方法相比,建立的方法具有简单、无毒、成本低的优点,用于实际水样中铅的分析能够获得满意的结果。A chicken eggshell membrane （ESM） is composed of many protein fibers, and available in large quantities as a by-product of the food industry. According to a study by Scanning Electron Microscope （SEM） and Fourier Transform Infrared （FTIR） Spectrometry, the ESM with an intricate lattice network of stable and water- insoluble fibers, and special functional groups such as hydroxyl （-OH）, carboxyl （-COOH）, aminol （-NH2）, showed an excellent potential for adsorption and exchange of metal ions. In this paper, the ESM was applied to separate and enrich Pb（I]） from a water sample under a pH of 6. The trace lead eluted by 5 mL 3% HNO3 was determined by using Graphite Furnace Atomic Absorption Spectrometry （GFAAS）. Important parameters, such as the sample pH, sample flow rate, concentration and volume of eluent, and interference of coexisting ions were comprehensively studied and optimized. Under the optimized conditions, an enrichment factor of 30 was obtained. The method detection limit for lead was 0.017 ng/mL （30-） and the relative standard deviation （RSD, n = 11 ） was 3.45%. The recoveries of lead in the spiked environmental water samples ranged from 96.0% to 104.2%. The proposed method was applied to the determination of trace lead in environmental and drinking water samples with satisfactory results, which demonstrates that the ESM method can be a simple, low-cost, environmentally-friendly SPE adsorbent for lead pretreatment and enrichment from real water samples.

关 键 词：环境水样 铅 鸡蛋膜 固相萃取 石墨炉原子吸收光谱法 

分 类 号：O657.31[理学—分析化学] O614.433[理学—化学]