Polarity Switching Accurate Mass Measurement of Pharmaceutical Samples Using Desorption Electrospray Ionization and a Dual Ion Source Interfaced to an Orthogonal Acceleration Time-of-Flight Mass Spectrometer

Abstract

A novel approach for the rapid, accurate mass analysis of pharmaceutical solid, liquid, and cream formulations using desorption electrospray ionization (DESI) is described. The method is based on polarity switching and real-time accurate mass measurement in an orthogonal acceleration time-of-flight mass spectrometer fitted with a dual-inlet electrospray ion source. Infusion of a reference compound into one inlet provides a single-point "lock mass" for accurate mass measurement. The other inlet sprays solvent at the sample being investigated using DESI. Minimal sample preparation was required. Results demonstrate the ability to acquire simultaneously positive and negative accurate mass DESI data within the same acquisition, thus negating the need for repeat analysis in each ion mode. In this paper, drugs that preferentially ionize in a particular mode depending on their physiochemical properties are presented. Mass accuracy to within 2 mTh was obtained for all drugs sampled.

Detection of intermediates for the Eschweiler–Clarke reaction by liquid-phase reactive desorption electrospray ionization mass spectrometry

“…DESI-MS has been rapidly accepted as a very successful tool for the rapid and sensitive analysis of various analytes and different samples, such as pharmaceutical tablets, explosives, polymers, metabolites, proteins, metabolomic samples, intact bacteria, biological tissues imaging and other surfaces. [10][11][12][13][14][15][16][17][18] A recent development for DESI with improved selectivity and efficiency has been accomplished by doping specific reactive reagents in the DESI spray solvent. This allows specific solution-phase ion/molecule chemical reactions between the charged spray microdroplets and surface molecules to occur before the resulting secondary microdroplets are propelled into the mass analyzer.…”

Observation of allicin‐cysteine complex by reactive desorption electrospray ionization mass spectrometry for garlic

“…[18][19][20][21][22][23][24][25] In 2006, Cooks and co-workers found that if the DESI spray was doped with selective chemical reagents, it was possible to perform ion/molecule reactions between the charged microdroplets and an analyte exposed on a solid sample surface. 26 This DESI modality, which was first named as 'reactive' DESI, has proven successful in detecting TATP 27 and other explosives 28 on a variety of surfaces.…”

Analysis of pharmaceutical products and herbal medicines using ambient mass spectrometry

“…Various active pharmaceutical ingredients in different pharmaceutical products with the forms of tablet [30,[33][34][35][36][37][38][39][40][41][42][43], capsule [44], ointment [33,35,36,39], eye drop [33], cream [34,43], and gel [35,39,42] as well as a thermal degradation product of loratadine in Claritin tablet [33] were all successfully analyzed by DESI-MS with the strategy of surface desorption/ionization.…”