Aeromicelle?A new form of liquid aerosol for delivering aqueous samples into a single-particle mass spectrometer
Aeromicelle?A new form of liquid aerosol for delivering aqueous samples into a single-particle mass spectrometer
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Aeromicelle？一种新型液体气溶胶，用于将水样输送到单颗粒质谱仪中
DOI：
10.1016/j.talanta.2023.124616
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发表时间：
2023
期刊：
影响因子：
6.1
通讯作者：
Toyoda Michisato
中科院分区：
文献类型：
--
作者：
Furutani Hiroshi;Kato Kana;Hinoue Teruo;Kimoto Takashi;Toyoda Michisato
为了将高灵敏度质谱法应用于含水样品的化学分析，我们开发了一种新技术，使用一种新的液滴形式，我们称之为“气凝胶”（AM），将含水样品溶液直接以液体形式输送到单粒子质谱仪的真空区域，并进行即时的质量分析。AMs是通过将含有表面活性剂的水溶液以显著低于其临界胶束浓度（CMC）的浓度喷射而产生的。当喷射溶液时，形成含有表面活性剂的液滴，液滴在气流中逐渐干燥。干燥后，液滴中的表面活性剂浓度超过其CMC，因此，表面活性剂分子开始覆盖液滴表面。最后，表面有望被表面活性剂分子（如反胶束）完全覆盖。表面覆盖有助于抑制水分的蒸发，从而延长液滴的停留时间。我们的实验结果表明，AMs在空气中至少保持了100秒的液体形态，即使在真空条件下也能存活下来进行进一步的质量分析：在单粒子质谱仪的真空区域传递的每个AM都用强激光脉冲烧蚀，然后进行质量分析。用单粒子质谱仪分析了从含CsCl的水溶液中产生的单个AMs。即使在10 nM溶液生成的AMs中也观察到Cs+离子峰。估计每个AM中的Cs原子数约为7 × 103，对应于1.2 × 10−20mol （12 zmol）。同时，在对酪氨酸的质谱分析中，在质谱上观察到AMs中酪氨酸的正负断裂离子，检测到4.6 × 105（760 zmol）酪氨酸分子。
For applying highly sensitive mass spectrometry to chemical analysis of aqueous samples, we have developed a novel technique using a new form of liquid droplets, which we call “aeromicelle” (AM), to deliver aqueous sample solutions directly into the vacuum region of a single-particle mass spectrometer in liquid form and conduct immediate mass analysis. AMs are generated by spraying an aqueous solution containing a surfactant at a concentration significantly lower than its critical micelle concentration (CMC). When the solution is sprayed, liquid droplets containing the surfactant are formed, which gradually dry in an air flow. Upon drying, the surfactant concentration in the droplet exceeds its CMC, and consequently, the surfactant molecules begin to cover the droplet surface. Finally, the surface is expected to be fully covered with surfactant molecules such as reverse micelles. The surface coverage helps suppress the evaporation of water, thereby enhancing the residence time of the liquid droplet. Our experimental results show that the AMs retained a liquid form for at least 100 s in air and survived even under vacuum conditions for further mass analysis: each AM delivered in the vacuum region of a single-particle mass spectrometer is ablated with an intense laser pulse and then, mass analyzed. Individual AMs generated from an aqueous solution containing CsCl were analyzed using a single-particle mass spectrometer. The Cs+ion peak was observed even in AMs generated from the 10 nM solution. The number of Cs atoms in each AM was estimated to be approximately 7 × 103, which corresponds to 1.2 × 10−20mol (12 zmol). Meanwhile, in the mass analysis of tyrosine, both positive and negative fragmentation ions from tyrosine in AMs were observed in the mass spectrum and 4.6 × 105(760 zmol) tyrosine molecules were detected.