Goodwin Joseph, Kenneth Marcus R, McRae Garnet, Sturgeon Ralph E, Mester Zoltan
Department of Chemistry, Clemson University, Clemson, SC, 29634, USA.
Metrology Research Center, National Research Council Canada, Ottawa, Ontario, K1A0R6, Canada.
Anal Bioanal Chem. 2024 Jun;416(15):3585-3594. doi: 10.1007/s00216-024-05312-x. Epub 2024 May 4.
A liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source operating at a nominal power of 30 W and solution flow rate of 30 µL min and supported in a He sheath gas flow rate of 500 mL min was interfaced to an Orbitrap mass spectrometer and assessed for use in rapid identification of inorganic and organic arsenic species, including As(III), As(V), monomethylarsonic acid, dimethylarsinic acid, and arsenobetaine in a 2% (v/v) nitric acid medium. Mass spectral acquisition in low-resolution mode, using only the ion trap analyzer, provided detection of protonated molecular ions for AsBet (m/z 179), DMA (m/z 139), MMA (m/z 141), and As(V) (m/z 143). As(III) is oxidized to As(V), likely due to in-source processes. Typical fragmentation of these compounds resulted in the loss of either water or methyl groups, as appropriate, i.e., introducing DMA also generated ions corresponding to MMA and As(V) as dissociation products. Structure assignments were also confirmed by high-resolution Orbitrap measurements. Spectral fingerprint assignments were based on the introduction of solutions containing 5 µg mL of each arsenic compound.
一种液体采样-常压辉光放电（LS-APGD）电离源，其标称功率为30 W，溶液流速为30 μL/min，并在500 mL/min的氦鞘气流中运行，与一台轨道阱质谱仪相连，用于在2%（v/v）硝酸介质中快速鉴定无机和有机砷物种，包括As(III)、As(V)、一甲基砷酸、二甲基砷酸和砷甜菜碱。仅使用离子阱分析仪在低分辨率模式下进行质谱采集，可检测到AsBet（m/z 179）、DMA（m/z 139）、MMA（m/z 141）和As(V)（m/z 143）的质子化分子离子。As(III)可能由于源内过程被氧化为As(V)。这些化合物的典型碎片化导致适当情况下失去水或甲基基团，即引入DMA也会产生对应于MMA和As(V)的离子作为解离产物。结构归属也通过高分辨率轨道阱测量得到证实。光谱指纹归属基于引入含有5 μg/mL每种砷化合物的溶液。
