Thermal Production and Reactions of Organic Ions at Atmospheric Pressure

Quantitative paper spray mass spectrometry analysis of drugs of abuse

“…Starting with desorption electrospray ionization (DESI) 14 and direct analysis in real-time (DART), 15 many ambient ionization methods have been reported, such as atmospheric solids analysis probe (ASAP), 16 surface sampling probe (SSP), 17 extractive electrospray ionization (EESI), 18 laser-ablation electrospray ionization (LAESI), 19 matrix-assisted laser desorption electrospray ionization (MALDESI) 20 and atmospheric-pressure thermal desorption ionization (APTDI). 21 The application of ambient ionization to the analysis of dried blood spot (DBS) samples is of a significant interest, since DBS is becoming a standard method for storage and transport of blood samples. 22 A very small amount (10 µL–20 µL) of blood is needed for one DBS, which allows less invasive methods for screening, such as finger prick, to be utilized when taking the sample.…”

In Situ Bioconjugation and Ambient Surface Modification Using Reactive Charged Droplets

“…(3) There is also a growing interest to utilize the charged droplet environment for small-scale, combinatorial synthesis because of the accelerated reaction rates associated with the ambient charged droplet environment. 13,[35][36][37][38][39] Atmospheric pressure droplet reactions are attractive considering it is simpler and more effective to conduct chemical reactions compared with conventional wetchemistry based approach (scheme 1c). For example, rapid solvent evaporation from the smaller micro-droplets (radius ranges 1-5 µm) [40][41][42] and/or thin liquid films created in an electrospray process has been found to cause moderate pH values in the starting solution to reach extreme values accompanied by increased reagent concentrations.…”

Precursor ion scan profiles of acylcarnitines by atmospheric pressure thermal desorption chemical ionization tandem mass spectrometry

“…To date, at least 15 ambient mass spectrometry methods have been described and grouped into ESI‐related techniques, such as DESI,1 DeSSI,6 SSP,7 ELDI,8 MALDESI9 and LAESI,10 and into atmospheric pressure chemical ionization (APCI)‐related techniques, such as DART,4 DAPCI,11 ASAP,12 DBDI,13 HAPGDI,14 PADI15 and APTDI 16. A description of all these desorption and ionization mechanisms has recently been reviewed 5.…”

“…Using APTDI, organic salts, deposited and dried in a tube near the outlet end, were heated from room temperature to an upper limit that ranged from 100–450°C, causing thermal desorption at 1–2 cm from the atmospheric pressure interface. A nitrogen gas stream at a flow rate of 10 L/min carries the ions thermally generated through the atmospheric pressure interface and into the mass spectrometer 16. Since APTDI usually generates intact cations/anions from salts and gives very simple mass spectra, the authors performed homogeneous ion‐molecule reactions at atmospheric pressure outside the mass spectrometer between reactant and neutral reagent.…”

“…The desorption momentum is induced by a simultaneous action of nebulizer gas and temperature, combined with a chemical ionization momentum induced by corona discharge. This method was applied for the first time to analyze acylcarnitines; it is similar to APTDI16 but the desorption/ionization of metabolites was obtained at atmospheric pressure using a corona discharge without reactants such as organic salts. Here we demonstrate that the most critical parameters are the temperature and flow of the desolvation gas.…”