Department of Chemistry and Biochemistry, University of the Science, Philadelphia, Pennsylvania, USA.
Anal Chem. 2011 Oct 15;83(20):7591-4. doi: 10.1021/ac201982r. Epub 2011 Sep 20.
Inlet ionization is a new approach for ionizing both small and large molecules in solids or liquid solvents with high sensitivity. The utility of solvent based inlet ionization mass spectrometry (MS) as a method for analysis of volatile and nonvolatile compounds eluting from a liquid chromatography (LC) column is demonstrated. This new LC/MS approach uses reverse phase solvent systems common to electrospray ionization MS. The first LC/MS analyses using this novel approach produced sharp chromatographic peaks and good quality full mass range mass spectra for over 25 peptides from injection of only 1 pmol of a tryptic digest of bovine serum albumin using an eluent flow rate of 55 μL min(-1). Similarly, full acquisition LC/MS/MS of the MH(+) ion of the drug clozapine, using the same solvent flow rate, produced a signal-to-noise ratio of 54 for the major fragment ion with injection of only 1 μL of a 2 ppb solution. LC/MS results were acquired on two different manufacturer's mass spectrometers using a Waters Corporation NanoAcquity liquid chromatograph.
入口离子化是一种新的方法，可用于在固体或液体溶剂中对小分子和大分子进行高效敏度的离子化。本文展示了基于溶剂的入口离子化质谱（MS）作为一种从液相色谱（LC）柱洗脱的挥发性和非挥发性化合物分析方法的实用性。这种新的 LC/MS 方法使用与电喷雾电离 MS 常见的反相溶剂系统。使用这种新方法的首次 LC/MS 分析仅在注射 1 pmol 牛血清白蛋白胰蛋白酶消化物的情况下，就产生了尖锐的色谱峰和高质量的全质量范围质谱，洗脱流速为 55 μL/min(-1)。同样，使用相同的溶剂流速对药物氯氮平的 MH(+) 离子进行全采集 LC/MS/MS，仅注入 1 μL 2 ppb 溶液，即可获得 54 的信噪比。LC/MS 结果是在两台不同制造商的质谱仪上使用 Waters 公司的 NanoAcquity 液相色谱仪获得的。
