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AC Electrokinetic Phenomena Generated by Microelectrode Structures
Published on: July 28, 2008
電気スプレーイオン化における電荷と超電荷の分子のメカニズム
Anthony T Iavarone1, Evan R Williams
1Contribution from the Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
Journal of the American Chemical Society
|February 20, 2003
まとめ
電気スプレー滴の表面張りは,分析物電荷に大きな影響を及ぼします. この研究は,電気スプレーイオン化における多重電荷イオン形成のための電荷残留メカニズムを支持しています.
科学分野:
- アナリティカル・ケミストリー (Analytical Chemistry) とは
- 物理化学 物理化学
- マススペクトロメトリーによる質量スペクトロメトリーです.
背景:
- 電気スプレーイオン化 (ESI) で多重電荷イオンが形成されるメカニズムについては,長い間議論されてきた.
- ESIにおける分析イオンの電荷状態に影響を与える要因は複雑で,完全に理解されていません.
研究 の 目的:
- ESIにおける様々な分析物質の充電量を決定する際に溶媒表面張りの役割を調査する.
- ESIにおける既存のイオン形成メカニズムを支持または反証する証拠を提供すること.
主な方法:
- 異なる組成の溶液から,ポリプロピレンイミネ (polypropyleneimine) デンドリマー,シトクロームc,ポリエチレングリコール,および1,n-ダイアミノアルカンを電圧でイオン化する.
- m-ニトロベンジルアルコール (m-NBA) を含む単一成分溶液および混合物を使用することにより,溶媒表面張力の体系的な変化.
- 分析物質の電荷状態と溶媒の表面張りの相関分析,レイリー限界電荷との比較.
主要な成果:
- 分析物質の電荷状態は,溶解過程の遅い段階で,電気スプレードロップレットの表面張力と有意に相関しています.
- 初期溶液の表面張力に対してm-NBA.の表面張力に基づいて,m-NBA.の変化した分析剤の充電を加えた.
- デンドリマーと1,n-ダイアミノアルカンの電荷状態と,それらの計算されたレイリー限界電荷との間に強い相関が観察されました.
結論:
- 結果は,ESIにおける多重電荷の有機イオン形成の主要な経路として,充電された残留メカニズムを強く支持しています.
- イオン蒸発メカニズムは,特にデンドリマーと1,n-ダイアミノアルカンでは,それほど重要な役割を果たさないようです.
- 溶媒の表面張りは,電気スプレーイオン化におけるイオン充電に影響を与える重要な,定量化可能な要因です.
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