Tiina J. Kauppila

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An ambient ionization technique for mass spectrometry, desorption atmospheric pressure photoionization (DAPPI), is presented, and its application to the rapid analysis of compounds of various polarities on surfaces is demonstrated. The DAPPI technique relies on a heated nebulizer microchip delivering a heated jet of vaporized solvent, e.g., toluene, and a(More)
A heat-assisted laser ablation electrospray ionization (HA-LAESI) method for the simultaneous mass spectrometric analysis of nonpolar and polar analytes was developed. The sample was introduced using mid-infrared laser ablation of a water-rich target. The ablated analytes were ionized with an electrospray plume, which was intercepted by a heated nitrogen(More)
The performance of nanoporous silicon (pSi) and ultra-thin layer chromatography (UTLC) plates as surfaces for desorption electrospray ionization (DESI) was compared with that of polymethyl methacrylate (PMMA) and polytetrafluoroethylene (PTFE), both popular surfaces in previous DESI studies. The limits of detection (LODs) and other analytical(More)
The ionization mechanism in dopant-assisted atmospheric pressure photoionization and the effect of solvent on the ionization efficiency was studied using 7 naphthalenes and 13 different solvent systems. The ionization efficiency was 1-2 orders of magnitude higher with dopant than without, indicating that the photoionization of the dopant initiates the(More)
The factors influencing desorption and ionization in newly developed desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS) were studied. Redirecting the DAPPI spray was observed to further improve the versatility of the technique: for dilute samples, parallel spray with increased analyte signal was found to be the best suited, while(More)
Desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS) is a versatile surface analysis technique for a wide range of analytes, especially for neutral and non-polar analytes. Here, a set of analytes typically found in environmental or food samples was analyzed by DAPPI-MS. The set included five polyaromatic hydrocarbons (PAHs), one(More)
Fast analysis of cannabis samples without prior sample preparation or chromatography was performed using desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS). The MS(2) spectra of the molecular ions of tetrahydrocannabinol (THC) and cannabidiol (CBD) formed in DAPPI-MS showed distinct product ions, unlike the protonated molecules(More)
In this paper we introduce laser ablation atmospheric pressure photoionization (LAAPPI), a novel atmospheric pressure ion source for mass spectrometry. In LAAPPI the analytes are ablated from water-rich solid samples or from aqueous solutions with an infrared (IR) laser running at 2.94 μm wavelength. Approximately 12 mm above the sample surface, the(More)
The most widely used ionization techniques in liquid chromatography-mass spectrometry (LC-MS) are electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). All three provide user friendly coupling of LC to MS. Achieving optimal LC-MS conditions is not always easy, however, owing to the(More)