نتایج جستجو برای: apci

تعداد نتایج: 399  

1996
Michael J. Carrott David C. Jones

Packed-column supercritical fluid chromatography (pSFC) with detection using atmospheric pressure chemical ionisation (APCI) mass spectrometry (MS) provides a versatile method for the detection and quantification of 20 polymer additives, including common antioxidants, light stabilisers and slip agents. Using MS with APCI in both positive and negative ion modes both molecular mass data and infor...

Journal: :Journal of chromatography. A 2005
Xueguo Chen Liang Kong Xingye Su Chensong Pan Mingliang Ye Hanfa Zou

An approach for the separation and identification of components in a traditional Chinese medicine Psoralea corylifolia was developed. Ion-exchange chromatography (IEC) was applied for the fractionation of P. corylifolia extract, and then followed by concentration of all the fractions with rotary vacuum evaporator. Each of the enriched fractions was then further separated on an ODS column with d...

2016
Heng-Hui Gan Christos Soukoulis Ian Fisk

In the present work, we have evaluated for first time the feasibility of APCI-MS volatile compound fingerprinting in conjunction with chemometrics (PLS-DA) as a new strategy for rapid and non-destructive food classification. For this purpose 202 clarified monovarietal juices extracted from apples differing in their botanical and geographical origin were used for evaluation of the performance of...

Journal: :gas processing 0
hojat ansarinasab energy systems engineering department, faculty of mahmoud abad, petroleum university of technology, mahmoud abad, iran. mahmoud afshar energy systems engineering department, faculty of mahmoud abad, petroleum university of technology, mahmoud abad, iran. mehdi mehrpooya hydrogen and fuel cell laboratory, faculty of new sciences and technologies, university of tehran, tehran, iran.

several processes have been proposed for natural gas liquefaction due to the vast utilization of lng as a reliable and relatively easy to use fuel. even though the merits and demerits of different process have been studied, a dearth of comprehensive technical and economical comparative investigation of these methods makes further broad examination a necessity. this article is presented to addre...

Journal: :Journal of chromatography. A 2003
Meng-chun Gao Min Yang Jian-ying Hu Bing Shao Hai-feng Zhang Hong-yan Li

A sensitive analytical method has been developed for identification of ubiquinones (UQ-n(Hx)) and menaquinones (MK-n(Hx)) in activated sludge by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry in negative mode (LC-NI-APCI-MS). Extraction and clean-up of samples were carried out on Sep-Pak Plus Silica solid-phase extraction cartridges. Complete separation of quin...

Journal: :The Analyst 2001
H R Mottram Z M Crossman R P Evershed

High performance liquid chromatography-atmospheric pressure chemical ionisation mass spectrometry (HPLC-APCI MS) was applied to the characterisation of triacylglycerols (TAGs) in animal fats. The major TAGs in four fats (beef, chicken, lamb and pork) were identified and positional isomers assigned according to their APCI mass spectra. Beef and lamb fat TAGs were confirmed as containing higher p...

Journal: :Chemical & pharmaceutical bulletin 2000
K Wada T Mori N Kawahara

High-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS) was successfully applied to seven stereoisomeric diterpenoid alkaloids at position 1 or 12. Comparison of the breakdown curves, observed by changing the potential difference between the first electrode and the second electrode of the APCI ion source, revealed stereochemical dependenc...

Journal: :Analytical chemistry 2006
Gavin L Sacks Louis A Derry J Thomas Brenna

Trace elemental speciation in complex, real-world matrixes is a daunting task because of the low concentration of metals/metalloids and the correspondingly high molecular chemical noise. We constructed a liquid chromatography parallel elemental and molecular mass spectrometry (PEMMS) system and evaluated the use of peak elution profiles to identify trace molecular species containing specific he...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2009
Issey Osaka Arifumi Yoshimoto Kazuyoshi Nozaki Hiroshi Moriwaki Hideya Kawasaki Ryuichi Arakawa

The simultaneous LC/MS analyses of hexachlorobenzene (HCB) and pentachlorophenol (PCP), two dioxin precursors were studied by both atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization mass spectrometry (APPI/MS). The optimum LC/MS conditions of the simultaneous analysis were determined for these two compounds with different polarity. Ionization by APPI was fo...

Journal: :Biochemical systematics and ecology 2000
Rezanka

The presence and identity of very long chain polyunsaturated fatty acids from three freshwater crustacean species, Bathynella natans, B. baicalensis and Baicalobathynella magna from Lake Baikal and caves of central Europe were determined by means of liquid chromatography-mass spectrometry with atmospheric pressure chemical ionization (LC-MS with APCI). LC-MS with APCI enabled the identification...

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