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1. Direct coupling of packed column supercritical fluid chromatography to continuous corona discharge ion mobility spectrometry

Author:
A. Rahmanian; H.S. Ghaziaskar; T. Khayamian
Source:
Journal of chromatography 2013 v.1272 no. pp. 126-131
ISSN:
0021-9673
Subject:
caffeine; carbon dioxide; detectors; electrodes; freezing; gases; ionization; medroxyprogesterone; methanol; spectroscopy; supercritical fluid chromatography; testosterone; theophylline
Abstract:
... In this study, packed column supercritical fluid chromatography (SFC) was directly coupled to a continuous corona discharge (CD) ion mobility spectrometer (IMS) with several modifications. The main advantage of the developed detector is its capability to introduce full column effluent up to 2000mLmin⁻¹ CO₂ gas directly into the IMS cell relative to 40mLmin⁻¹ CO₂ gas as a maximum tolerance, reporte ...
DOI:
10.1016/j.chroma.2012.11.063

2. Looking into individual coffee beans during the roasting process: direct micro-probe sampling on-line photo-ionisation mass spectrometric analysis of coffee roasting gases

Author:
Romy Hertz-Schünemann; Thorsten Streibel; Sven Ehlert; Ralf Zimmermann
Source:
Analytical and bioanalytical chemistry 2013 v.405 no.22 pp. 7083-7096
ISSN:
1618-2642
Subject:
Coffea arabica; Coffea canephora; caffeine; coffee beans; cultivars; flavor compounds; gases; ionization; lipids; mass spectrometry; multivariate analysis; phenol; roasting; temporal variation; volatile organic compounds
Abstract:
... A micro-probe (μ-probe) gas sampling device for on-line analysis of gases evolving in confined, small objects by single-photon ionisation time-of-flight mass spectrometry (SPI-TOFMS) was developed. The technique is applied for the first time in a feasibility study to record the formation of volatile and flavour compounds during the roasting process within (inside) or in the direct vicinity (outsid ...
DOI:
10.1007/s00216-013-7006-y

3. Miniature Flow-Through Low-Temperature Plasma Ionization Source for Ambient Ionization of Gases and Aerosols

Author:
Spencer Sandra E.; Santiago Brandon G.; Glish Gary L.
Source:
Analytical chemistry 2015 v.87 no.23 pp. 11887-11892
ISSN:
1520-6882
Subject:
aerosols; caffeine; cellulose; gases; ionization; ions; pyrolysis
Abstract:
... The design and operation of an inexpensive, miniature low-temperature plasma ion source is detailed. The miniature low-temperature plasma ion source is operated in a “flow-through” configuration, wherein the gaseous or aerosolized analyte, caffeine or pyrolyzed ethyl cellulose, in a carrier gas is used as the plasma gas. In this flow-through configuration, the sensitivity for the caffeine standard ...
DOI:
10.1021/acs.analchem.5b03447