Thermal desorption counter‐flow introduction atmospheric pressure chemical ionization for direct mass spectrometry of ecstasy tablets

Abstract

A novel approach to the analysis of ecstasy tablets by direct mass spectrometry coupled with thermal desorption (TD) and counter-flow introduction atmospheric pressure chemical ionization (CFI-APCI) is described. Analytes were thermally desorbed with a metal block heater and introduced to a CFI-APCI source with ambient air by a diaphragm pump. Water in the air was sufficient to act as the reactive reagent responsible for the generation of ions in the positive corona discharge. TD-CFI-APCI required neither a nebulizing gas nor solvent flow and the accompanying laborious optimizations. Ions generated were sent in the direction opposite to the air flow by an electric field and introduced into an ion trap mass spectrometer. The major ions corresponding to the protonated molecules ([M + H](+)) were observed with several fragment ions in full scan mass spectrometry (MS) mode. Collision-induced dissociation of protonated molecules gave characteristic product-ion mass spectra and provided identification of the analytes within 5 s. The method required neither sample pretreatment nor a chromatographic separation step. The effectiveness of the combination of TD and CFI-APCI was demonstrated by application to the direct mass spectrometric analysis of ecstasy tablets and legal pharmaceutical products.

Thin‐layer chromatography and mass spectrometry coupled using proximal probe thermal desorption with electrospray or atmospheric pressure chemical ionization

“…2). Others have already demonstrated this same type of counter flow sample vapor introduction for ambient ionization to be highly effective 28…”

The Variability of Ecstasy Tablets Composition in Brazil

“…Other techniques including gas chromatography‐flame ionization detection (GC‐FID) , two‐dimensional gas chromatography , high‐performance liquid chromatography‐diode array detection (HPLC‐DAD) , and capillary electrophoresis have been used in the past . Stand‐alone mass spectrometry (not coupled to separation techniques) has also been applied for ATS analyses .…”

Laser microdissection and atmospheric pressure chemical ionization mass spectrometry coupled for multimodal imaging

“…An optimized gas flow rate of 3–4 mL/min into the source enclosure through the sampling capillary was monitored using an Aalborg GFM37 mass flow meter (Aalborg, Orangeburg, NY, USA). This type of approach for sampling directly into an ion source in a counter flow mode or, more commonly, straight line introduction has been demonstrated for ionization of vapors produced by thermal desorption of analytes using APCI or ESI. Mass spectral data were recorded with the automatic gain control (AGC) turned off.…”