High performance liquid thermospray ionization

A method that uses high performance liquid chromatography/ mass spectrometry (HPLC/MS) for the analysis of chlorinated phenoxyacid herbicides is described. During method development different techniques were used to increase both the sensitivity and the specificity of thermospray HPLC/MS for chlorinated acid herbicides. These included the operation of the instrument in the negative chemical ionization (NCI) mode initiated by discharge and the use of a wire-repeller in the ion source for efficient extraction of positive ions. Single quadrupole repeller-induced and multiple quadrupole collision activated dissociation (CAD) experiments were also performed to increase the structural information of the mass spectra. 

Vitanyi G, Bihasti-Karsai E, Lefler J, Lelik L (1997) Application of high performance liquid chromatographyMass spectrometry with thermospray ionization to the detection of quassinoids extracted liom Quassia amara L. Rapid Commun Mass Spectrom 11 691-693... 

High performance liquid chromatography is well established as a tool for the separation of mixtures of labile biological substances, but its combination with mass spectrometry (LC/MS) remains fraught with difficulties as a valid analytical procedure. Several new types of direct liquid introduction interfaces (as opposed to transport interfaces) have been developed recently and appear to offer promise for the future. The thermospray interface 44) has been used successfully for amino acids, small peptides, nucleosides, antibiotics and glucuronides. The spectra are the relatively simple ones commonly obtained from soft ionization methods and resemble those obtained by FABMS. A gas nebulizer interface has enabled representative spectra (resembling those generated from DCI) to be... 

Significant advances with the ionization source have been made. The pioneering work of many outstanding scientists with moving belt [34-36], direct liquid introduction (DLI) [37-39], thermospray ionization (TSI) [40,41], and ESI [42-44] set the stage for the development of modem ionization sources for high-performance LC-MS analysis. 

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