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1. Challenging applications offered by direct analysis in real time (DART) in food-quality and safety analysis

Author:
Vaclavik, Lukas,   et al.   ; Hajslova, Jana; Cajka, Tomas;     Show all 3 Authors
Source:
Trends in analytical chemistry 2011 v.30 no.2 pp. 204-218
ISSN:
0165-9936
Subject:
atmospheric pressure; desorption; equipment performance; food analysis; food law; food matrix; food safety; ionization; mass spectrometry; pretreatment; spectrometers
Abstract:
... Direct analysis in real time (DART) is an ambient ionization technique undergoing rapid development. With minimal sample pre-treatment, ionization of analyte molecules outside the mass spectrometry (MS) instrument in the ordinary atmosphere is feasible. This ionization approach relies upon the fundamental principles of atmospheric pressure chemical ionization. The current review highlights and cri ...
DOI:
10.1016/j.trac.2010.11.001

2. Characterization of fatty acid and triacylglycerol composition in animal fats using silver-ion and non-aqueous reversed-phase high-performance liquid chromatography/mass spectrometry and gas chromatography/flame ionization detection

Author:
Franěk, Lukáš,   et al.   ; Lísa, Miroslav; Netušilová, Kateřina; Dvořáková, Hana; Vrkoslav, Vladimír; Holčapek, Michal;     Show all 6 Authors
Source:
Journal of chromatography 2011 v.1218 no.42 pp. 7499-7510
ISSN:
0021-9673
Subject:
Cervus dama; Cervus elaphus; animal fats and oils; atmospheric pressure; chronic diseases; diet; ducks; fatty acid methyl esters; fatty acids; flame ionization; gas chromatography-mass spectrometry; glycerol; human health; ionization; isomers; rabbits; reversed-phase high performance liquid chromatography; sheep; skeleton; triacylglycerols; wild boars
Abstract:
... Fatty acid (FA) and triacylglycerol (TG) composition of natural oils and fats intake in the diet has a strong influence on the human health and chronic diseases. In this work, non-aqueous reversed-phase (NARP) and silver-ion high-performance liquid chromatography with atmospheric pressure chemical ionization mass spectrometry detection and gas chromatography with flame-ionization detection (GC/FID ...
DOI:
10.1016/j.chroma.2011.07.032

3. Gas-phase basicity of several common MALDI matrices measured by a simple experimental approach

Author:
Fritsche, Lukas,   et al.   ; Barylyuk, Konstantin; Balabin, Roman M.; Nieckarz, Robert; Zenobi, Renato;     Show all 5 Authors
Source:
RSC advances 2012 v.2 no.5 pp. 1962-1969
ISSN:
2046-2069
Subject:
atmospheric pressure; ferulic acid; gases; heterocyclic compounds; ionization; ions; isomers; organic matter; spectrometers; thermodynamics
Abstract:
... We present a combined experimental and theoretical study to determine the gas-phase basicity of several relatively small organic molecules that are used as matrices in MALDI: alpha-cyano-4-hydroxycynnamic acid (αCHCA), ferulic acid (FA), 3-hydroxypicolinic acid (HPA), sinapinic acid (SA), and 2,4,6-trihydroxyacetophenone (THAP). Our simple and fast experimental approach utilizes the ability of an ...
DOI:
10.1039/c1ra01117k

4. Experimental and numerical study of MILD combustion for gas turbine applications

Author:
Berger, Lukas,   et al.   ; Kruse, Stephan; Kerschgens, Bruno; Varea, Emilien; Pitsch, Heinz;     Show all 5 Authors
Source:
Applied energy 2015 v.148 pp. 456-465
ISSN:
0306-2619
Subject:
atmospheric pressure; carbon monoxide; combustion; emissions; gases; mass flow; mixing; nitrogen oxides
Abstract:
... In this paper, the pressure influence on the MILD combustion process and on emissions is examined. Experiments were performed in a combustion chamber based on the reverse flow configuration to enhance mixing of fresh and burnt gases. First, investigations under atmospheric pressure were performed to determine the regime of jointly low NOx and CO emissions. Afterwards, the effects of burnt gas reci ...
DOI:
10.1016/j.apenergy.2015.03.054

5. Gas Diffusion Barriers Prepared by Spatial Atmospheric Pressure Plasma Enhanced ALD

Author:
Hoffmann, Lukas,   et al.   ; Theirich, Detlef; Pack, Sven; Kocak, Firat; Schlamm, Daniel; Hasselmann, Tim; Fahl, Henry; Räupke, André; Gargouri, Hassan; Riedl, Thomas;     Show all 10 Authors
Source:
ACS Applied Materials & Interfaces 2017 v.9 no.4 pp. 4171-4176
ISSN:
1944-8252
Subject:
activation energy; aluminum oxide; atmospheric pressure; temperature; water vapor
Abstract:
... In this work, we report on aluminum oxide (Al₂O₃) gas permeation barriers prepared by spatial ALD (SALD) at atmospheric pressure. We compare the growth characteristics and layer properties using trimethylaluminum (TMA) in combination with an Ar/O₂ remote atmospheric pressure plasma for different substrate velocities and different temperatures. The resulting Al₂O₃ films show ultralow water vapor tr ...
DOI:
10.1021/acsami.6b13380

6. Spatial Atmospheric Pressure Atomic Layer Deposition of Tin Oxide as an Impermeable Electron Extraction Layer for Perovskite Solar Cells with Enhanced Thermal Stability

Author:
Hoffmann, Lukas,   et al.   ; Brinkmann, Kai O.; Malerczyk, Jessica; Rogalla, Detlef; Becker, Tim; Theirich, Detlef; Shutsko, Ivan; Görrn, Patrick; Riedl, Thomas;     Show all 9 Authors
Source:
ACS applied materials & interfaces 2018 v.10 no.6 pp. 6006-6013
ISSN:
1944-8252
Subject:
air; atmospheric pressure; electrical conductivity; halogens; manufacturing; materials science; oxides; solar cells; temperature; thermal stability; transmittance; water vapor
Abstract:
... Despite the notable success of hybrid halide perovskite-based solar cells, their long-term stability is still a key-issue. Aside from optimizing the photoactive perovskite, the cell design states a powerful lever to improve stability under various stress conditions. Dedicated electrically conductive diffusion barriers inside the cell stack, that counteract the ingress of moisture and prevent the m ...
DOI:
10.1021/acsami.7b17701

7. Impact of vacuum frying on quality of potato crisps and frying oil

Author:
Vaclavik, Lukas,   et al.   ; Belkova, Beverly; Hradecky, Jaromir; Hurkova, Kamila; Forstova, Veronika; Hajslova, Jana;     Show all 6 Authors
Source:
Food chemistry 2018 v.241 pp. 51-59
ISSN:
0308-8146
Subject:
Aepyceros melampus; Maillard reaction products; acrylamides; alpha-chlorohydrin; atmospheric pressure; esters; flavor; frying; frying oil; potato chips; potatoes; pyrazines; rapeseed oil; temperature
Abstract:
... This research was focused on a critical assessment of vacuum frying as a technology enabling minimization of acrylamide formation in potato crisps and reducing undesirable chemical changes that occur in frying oil at high temperatures. The potato slices were fried in rapeseed oil under vacuum at 125°C and atmospheric pressure at 165°C. The experiments were performed on two potato varieties, Saturn ...
DOI:
10.1016/j.foodchem.2017.08.062

8. Detection of RO2 radicals and other products from cyclohexene ozonolysis with NH4+ and acetate chemical ionization mass spectrometry

Author:
Fischer, Lukas,   et al.   ; Hansel, Armin; Scholz, Wiebke; Mentler, Bernhard; Berndt, Torsten;     Show all 5 Authors
Source:
Atmospheric environment 2018 v.186 pp. 248-255
ISSN:
1352-2310
Subject:
acetates; ammonium; atmospheric chemistry; atmospheric pressure; cyclohexenes; free radicals; gases; ionization; mass spectrometry; organic matter; oxidation; ozone; ozonolysis; spectrometers
Abstract:
... The performance of the novel ammonium chemical ionization time of flight mass spectrometer (NH4+-CI3–TOF) utilizing NH4+ adduct ion chemistry to measure first generation oxidized product molecules (OMs) as well as highly oxidized organic molecules (HOMs) was investigated for the first time. The gas-phase ozonolysis of cyclohexene served as a first test system. Experiments have been carried out in ...
DOI:
10.1016/j.atmosenv.2018.04.023

9. Method development and validation for low-level propineb and propylenethiourea analysis in baby food, infant formula and related matrices using liquid chromatography-tandem mass spectrometry

Author:
Vaclavik, Lukas,   et al.   ; Shippar, Jeffrey J.; Koesukwiwat, Urairat; Mastovska, Katerina;     Show all 4 Authors
Source:
Food additives & contaminants 2018 v.35 no.12 pp. 2387-2399
ISSN:
1944-0057
Subject:
European Union; atmospheric pressure; carbohydrates; derivatization; emulsifiers; infant formulas; ionization; laws and regulations; liquid chromatography; maximum residue limits; monitoring; raw materials; solid phase extraction; soy protein isolate; soybean oil; tandem mass spectrometry; vegetable oil
Abstract:
... Two simple, selective and rugged liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were developed and validated for determination of propineb and propylenethiourea (PTU) in infant formula, fruit-based and cereal-based baby food and raw materials used in production of infant formula, including carbohydrates, protein isolates, vegetable oils and emulsifiers. The sample preparation pr ...
DOI:
10.1080/19440049.2018.1539529