نتایج جستجو برای: UV-HPLC / APCI-MS
تعداد نتایج: 217767 فیلتر نتایج به سال:
an on-line uv-hplc / apci-ms (atmospheric pressure chemical ionization) tandem by a platinium c18 column with an isocratic solvent system after optimizing was applied to the separation and the identification of different carotenoids including astaxanthin, canthaxanthin, apocarotenoic ester, torularhodin and beta carotene. this method was used to identify particular carotenoids produced by newly...
A new hydroxycinnamoyl polyamine derivative, N,N',N"-triferuloylspermidine (= (E)-N-(4-aminobutyl) -3,3',3"-tris(4-hydroxy-3-methoxyphenyl)-N,N',N"- (butane-1,4-diyl)tris [prop-2-enamide]) (1) was detected in the H2O/MeOH extract of pollen from Hippeastrum x hortorum. The compound was identified by on-line-coupled high-performance liquid chromatography and atmospheric-pressure chemical-ionizati...
The methods of extraction, separation and analysis of alkaloids and indole glucosinolates (GLs) ofIsatis tinctoria were reviewed. Different analytical approaches such as High-pressure Liquid Chromatography (HPLC), Liquid Chromatography with Electrospray Ionization Mass Spectrometry (LC/ESI/MS), Electrospray Ionization Time-Of-Flight Mass Spectrometry (ESI-TOF-MS), and Nuclear Magnetic Resonance...
This study presents an HPLC method for simultaneous analysis of astaxanthin and its carotenoid precursors from Xanthophyllomyces dendrorhous. The HPLC method is accomplished by employing a C18 column and the mobile phase methanol/water/acetonitrile/ dichloromethane (70:4:13:13, v/v/v/v). Astaxanthin is quantified by detection at 480 nm. The carotenoid precursors are identified by LC-APCI-MS and...
Ethanol and dichloromethane extracts of a Brazilian green propolis from Baccharis dracunculifolia were analyzed by HPLC-APCI-MS and GC-MS, respectively. The HPLCAPCI-MS technique, at the positive mode, furnished a complete and unequivocal chemical composition of the green propolis sample. It serves as fi ngerprint for different propolis samples. The composition of the ethanol extract consisted ...
The analysis of carotinoids is usually performed by HPLC with UV/VIS detection. Different geometric isomers can be separated using C30 stationary phases [1]. However, the complexity of most matrices makes an unequivocal identification very difficult. For this reason we investigated the use of an ion trap analyzer for the identification of carotinoids in spinach. Since carotinoids are rather non...
BACKGROUND Vitamin D is not only important for bone health but can also affect the development of several non-bone diseases. The definition of vitamin D insufficiency by serum levels of 25-hydroxyvitamin D depends on the clinical outcome but might also be a consequence of analytical methods used for the definition. Although numerous 25-hydroxyvitamin D assays are available, their comparability ...
The antioxidant activity of capsaicin, as compared to BHT and melatonin, was determined by the direct measurement of lipid hydroperoxides formed upon linoleic acid autoxidation initiated by AIBN. The formation of four isomeric lipid hydroperoxides was detected after reverse-phase HPLC separation. Data from three detectors, UV absorption, glassy carbon electrode electrochemical detection, and po...
In this work, the first systematic characterization of triacylglycerol (TG) enantiomers in real samples using chiral high-performance liquid chromatography (HPLC) with atmospheric pressure chemical ionization mass spectrometry (APCI-MS) is performed. Our chiral HPLC/APCI-MS method is based on the use of two cellulose-tris-(3,5-dimethylphenylcarbamate) columns connected in series using a gradien...
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...
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