Determination of Arsenic Compounds by High-Performance Liquid Chromatography-Ultrasonic Nebulizer-High Power Nitrogen-Microwave-Induced Plasma Mass Spectrometry: An Accepted Coupling

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• 作者：Amit Chatterjee ; Yasuyuki Shibata ; Jun Yoshinaga ; and Masatoshi Morita
• 刊名：Analytical Chemistry
• 出版年：2000
• 出版时间：September 15, 2000
• 年：2000
• 卷：72
• 期：18
• 页码：4402 - 4412
• 全文大小：126K
• 年卷期：v.72,no.18(September 15, 2000)
• ISSN：1520-6882

文摘

To establish a sensitive, accurate, and precise determination of arsenic compounds, a high power nitrogenmicrowave-induced plasma (1.3 kW) mass spectrometer(N₂-MIP-MS) has been successfully coupled with anultrasonic nebulizer (HPLC-USN) that is attached to ahigh-performance liquid chromatograph. It is examinedas an element-specific detector for its applicability to theoptimization and determination of seven arsenic compounds [arsenic acid, methylarsonic acid (MA), dimethylarsinic acid (DMA), arsenobetaine (AB), arsenocholine(AC), trimethylarsine oxide (TMAO), and tetramethylarsonium ion (TMI)]. This HPLC-USN-MIP-MS coupling isan encouraging combination as an alternative method formass spectroscopy for elemental speciation analysis.Interchanging of the MIP-MS fabricated nebulizer (concentric) with an ultrasonic nebulizer, increases 3-6 timesthe ion signals for the anionic and 6-12 times those forthe cationic arsenic compounds as compared to traditional methods. The HPLC-USN-MIP-MS combinationused is excellent, amplifying the ion signals about 1.5-2times for cationic and 1.3-2.8 times for the anionicarsenic compounds as compared to the HPLC-ICPMScoupling. The detection limits for As(V), MA, DMA, AB,TMAO, AC, and TMI (in Milli-Q-water) obtained with theoptimized HPLC-USN-N₂-MIP-MS system are 0.46, 0.36,0.73, 0.21, 3.64, 0.39, and 0.32 g L^-1, respectively,about 13-50 times lower than the HPLC-MIP-MS andabout 3-11 times lower than the HPLC-ICPMS. Thedetection limits of As(V), MA, DMA, AB, TMAO, AC, andTMI, which spike in the urine, are deteriorated by 1.7-4.2 times compared with the detection limits of the sevendifferent As compounds, which are prepared in the Milli-Q-water. The repeatability (RSD for three successiveanalyses) and reproducibility (RSD for three successiveanalyses performed on three different days), consideringpeak area and peak height, achieved for seven differentarsenic compounds are 0.5-7 and 0.7-8%, comparablewith the HPLC-ICPMS (0.3-8.5%; 4-12%) and HPLC-MIP-MS (0.4-9%; 5-12%) systems. The combined HPLC-USN-N₂-MIP-MS has been adequately applied to thedetermination of AB in NIES Candidate Human UrineCRM. The results agree with the HPLC-ICPMS values.Chloride interference as ⁴⁰Ar³⁵Cl⁺ is not found in the urineand with the high chloride matrix (10 000 mg L^-1).