title: Detection of trace levels of lead in aqueous liquids using extractive electrospray ionization tandem mass spectrometry.
abstract: A sensitive approach, based on semi-quantitative measurement of the characteristic fragments in multi-stage extractive electrospray ionization mass spectrometry (EESI-MS(n)), 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-MS(3) 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.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Liu
authors.forename: Xinglei
authors.initials: X
authors.lastname: Zhang
authors.forename: Saijin
authors.initials: S
authors.lastname: Xiao
authors.forename: Bin
authors.initials: B
authors.lastname: Jia
authors.forename: Shasha
authors.initials: S
authors.lastname: Cui
authors.forename: Jianbo
authors.initials: J
authors.lastname: Shi
authors.forename: Ning
authors.initials: N
authors.lastname: Xu
authors.forename: Xi
authors.initials: X
authors.lastname: Xie
authors.forename: Haiwei
authors.initials: H
authors.lastname: Gu
authors.forename: Huanwen
authors.initials: H
authors.lastname: Chen
mesh_terms: D001515:Beer / Q000032:analysis; D002253:Carbonated Beverages / Q000032:analysis; D002413:Cations, Divalent; D032084:Citrus sinensis / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D007854:Lead / Q000032:analysis*; D057230:Limit of Detection; D008900:Mineral Waters / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D013662:Tea / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002413:Cations, Divalent; D056831:Coordination Complexes; D008900:Mineral Waters; D013662:Tea; D014874:Water Pollutants, Chemical; D007854:Lead; D004492:Edetic Acid