Detection of trace levels of lead in aqueous liquids using extractive electrospray ionization tandem mass spectrometry

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• 作者：Chunxiao Liu ; Xinglei Zhang ; Saijin Xiao ; Bin Jia ; Shasha Cui ; Jianbo Shi ; Ning Xu ; Xi Xie ; Haiwei Gu ; Huanwen Chen
• 关键词：Extractive electrospray ionization ; Ambient mass spectrometry ; Tandem mass spectrometry ; Lead ; Beverage
• 刊名：Talanta
• 出版年：2012
• 出版时间：30 August, 2012
• 年：2012
• 卷：98
• 期：Complete
• 页码：79-85
• 全文大小：458 K

文摘

A sensitive approach, based on semi-quantitative measurement of the characteristic fragments in multi-stage extractive electrospray ionization mass spectrometry (EESI-MSⁿ), was developed for fast detection of trace levels of lead in aqueous liquids including mineral water, lake water, tap water, energy drinks, soft drinks, beer, orange juice, and tea. A disodium ethylene-diamine-tetraacetic acid (EDTA) aqueous solution was electrosprayed to produce negatively charged primary ions which then intersected the neutral sample plume to generate anions of EDTA-Pb(II) complexes. The charged EDTA-Pb(II) complexes were characterized with multistage collision induced dissociation (CID) experiments. The limit of detection (LOD) using EESI-MS³ was estimated to be at the level of 10^-13 g/mL for directly detecting lead in many of these samples. The linear dynamic range was higher than 2 orders of magnitude. A single sample analysis could be completed within 2 min with reasonable semi-quantitative performance, e.g., relative standard deviations (RSDs) for deionized water were 4.6-7.6 % during 5 experimental runs (each of them had 10 repeated measurements). Coca-cola and Huiyuan orange juice, representative beverage samples with complex matrices, generated recovery rates of 91.5 % and 129 % , respectively. Our experimental data demonstrated that EESI-MS is a useful tool for the fast detection of lead in various solutions, and EESI-MS showed promises for fast screening of lead-contaminated aqueous liquid samples.