van Wasen Sebastian, You Yi, Beck Sebastian, Riedel Jens, Volmer Dietrich A
Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter-Straße 11, 12489 Berlin, Germany.
Anal Chem. 2021 Apr 20;93(15):6019-6024. doi: 10.1021/acs.analchem.1c00762. Epub 2021 Apr 9.
A combination of acoustic levitation, laser vaporization, and atmospheric pressure chemical ionization mass spectrometry (APCI-MS) is presented in this study that enabled sensitive analysis of pharmaceutical drugs from an aqueous sample matrix. An unfocused pulsed infrared laser provided contactless sample desorption from the droplets trapped inside an acoustic levitator by activation of the OH stretching band of aqueous and alcoholic solvents. Subsequent atmospheric pressure chemical ionization was used between the levitated droplet and the mass spectrometer for postionization. In this setup, the unfocused laser gently desorbed the analytes by applying very mild repulsive forces. Detailed plume formation studies by temporally resolved schlieren experiments were used to characterize the liquid gas transition in this process. In addition, the role of different additives and solvent composition was examined during the ionization process. The analytical application of the technique and the proof-of-concept for quantitative analysis were demonstrated by the determination of selected pharmaceutical drugs in aqueous matrix with limits of quantification at the lower nanomolar level and a linear dynamic range of 3-4 orders of magnitude.
本研究提出了一种结合声悬浮、激光汽化和大气压化学电离质谱（APCI-MS）的方法，该方法能够对水性样品基质中的药物进行灵敏分析。通过激活水性和醇类溶剂的OH伸缩带，非聚焦脉冲红外激光实现了对声悬浮器内捕获液滴的非接触式样品解吸。随后在悬浮液滴和质谱仪之间使用大气压化学电离进行后电离。在此设置中，非聚焦激光通过施加非常温和的排斥力轻轻解吸分析物。通过时间分辨纹影实验进行的详细羽流形成研究用于表征该过程中的液-气转变。此外，还研究了不同添加剂和溶剂组成在电离过程中的作用。通过测定水性基质中选定的药物，证明了该技术的分析应用和定量分析的概念验证，其定量限为较低的纳摩尔水平，线性动态范围为3-4个数量级。
