New hyphenated technique for the extraction and determination of isoflavones in sea and freshwater algae and cyanobacteria was developed. The method consists of sonication sample pretreatment, extraction by supercritical CO(2) modified by 3% (v/v) of MeOH/H(2)O mixture (9:1, v/v) at 35 MPa and 40°C for 60 min, fast chromatography analysis by the means of Agilent 1200 Series Rapid Resolution and MS/MS determination. Agilent 1200 Series RRLC was used with Zorbax SB-CN chromatographic column (100 mm × 2.1mm, particle size 3.5 μm), 3μl injection volume, mobile phase consisting of 0.2% (v/v) acetic acid in water (solvent A) and acetonitrile (solvent B) and used with linear gradient (30% B at 0 min, from 0 min to 3 min up to 50% B, from 3 to 6 min up to 80% B and from 6 to 10 min down to 30% B). The flow-rate was 0.4 mL/min, column oven temperature 35°C. MS detector Agilent Technologies 6460 Triple quadrupole LC/MS with Agilent Jet Stream was used in a negative ESI mode under following conditions: gas temperature 350°C, gas flow 13 L/min, nebulizer gas pressure 50 psi, sheath gas temperature 400°C, sheath gas flow 12L/min, capillary voltage was 4 kV. Samples were analysed in the multiple reaction monitoring (MRM) mode. Eight isoflavone compounds were found for the first time in seven real samples of sea algae and in three control samples of freshwater algae and cyanobacteria. Usual optimisation study of extraction parameters was performed. Pressure and temperature optima for algae matrix are different from those obtained sooner for other matrices for most of the analytes, but the results of modifier optimisation study are in good accordance with those obtained sooner for spiked samples and red clover matrix. It seems that matrix has very small or no effect on the modifier selection. Two different approaches of sonication pretreatment were tested: sonication bath and the thorn instrument. In longer extraction time experiments, thorn sonication was more efficient and recovery of following supercritical fluid extraction was higher.
- MeSH
- chromatografie kapalinová metody MeSH
- isoflavony analýza izolace a purifikace MeSH
- Phaeophyceae chemie MeSH
- Rhodophyta chemie MeSH
- superkritická fluidní chromatografie přístrojové vybavení metody MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- ultrazvuk MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- isoflavony MeSH
Complete separation of aglycones and glucosides of selected isoflavones (genistin, genistein, daidzin, daidzein, glycitin, glycitein, ononin, sissotrin, formononetin, and biochanin A) was possible in 1.5 min using an ultrahigh-pressure liquid chromatography (U-HPLC) on a different particular chemically modified stationary phases with a particle size under 2 microm. In addition, selected separation conditions for simultaneous determination of isoflavones together with a group of phenolic acids (gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic, and sinapic acid) allowed separation of all 19 compounds in 1.9 min. Separations were conducted on a non-polar reversed phase (C(18)) and also on more polar phases with cyanopropyl or phenyl groups using a gradient elution with a mobile phase consisting of 0.3% aqueous acetic acid and methanol. Chromatographic peaks were characterised using parameters such as resolution, symmetry, selectivity, etc. Individual substances were identified and quantified using UV-vis diode array detector at wavelength 270 nm. Limits of detection (3S/N) were in the range 200-400 pg ml(-1). Proposed U-HPLC technique was used for separation of isoflavones and phenolic acids in samples of plant materials (Trifolium pratense, Glycine max, Pisum sativum and Ononis spinosa) after acid hydrolysis of the samples and modified Soxhlet extraction.
- MeSH
- genistein chemie izolace a purifikace MeSH
- Glycine max chemie MeSH
- hrách setý chemie MeSH
- hydroxybenzoáty chemie izolace a purifikace MeSH
- isoflavony chemie izolace a purifikace MeSH
- kyselina gallová analogy a deriváty chemie izolace a purifikace MeSH
- kyselina vanilová chemie izolace a purifikace MeSH
- kyseliny kávové chemie izolace a purifikace MeSH
- kyseliny kumarové chemie izolace a purifikace MeSH
- molekulární struktura MeSH
- propionáty MeSH
- rostlinné extrakty chemie izolace a purifikace MeSH
- Trifolium chemie MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biochanin A MeSH Prohlížeč
- caffeic acid MeSH Prohlížeč
- daidzein MeSH Prohlížeč
- daidzin MeSH Prohlížeč
- ferulic acid MeSH Prohlížeč
- formononetin MeSH Prohlížeč
- genistein MeSH
- genistin MeSH Prohlížeč
- glycitein MeSH Prohlížeč
- glycitin MeSH Prohlížeč
- hydroxybenzoáty MeSH
- isoflavony MeSH
- kyselina gallová MeSH
- kyselina vanilová MeSH
- kyseliny kávové MeSH
- kyseliny kumarové MeSH
- p-coumaric acid MeSH Prohlížeč
- phenolic acid MeSH Prohlížeč
- propionáty MeSH
- protocatechuic acid MeSH Prohlížeč
- rostlinné extrakty MeSH
- sinapinic acid MeSH Prohlížeč
- syringic acid MeSH Prohlížeč
Isoflavones belong to the natural substances exhibiting a number of physiological effects in living organisms. The substances are synthesized in plant tissues as protective agents against biotic stress (i.e. bacterial infection). Isoflavones are also an important dietary constituent in human nutrition. The review discusses modern trends in the studies of isoflavones in plant materials and foodstuffs and procedures for chemical analyses of isoflavones in human body fluids and plant tissues. Highly effective extraction and purification techniques, i.e. solid-phase extraction (SFE), accelerated-solvent extraction (ASE), and Soxhlet extraction, are presented. Latest procedures in chromatographic separation of isoflavones that apply different types of stationary phases are described. Immunochemical analysis, electrochemical sensing of isoflavones, spectrometric and other analytical techniques and their applications are also mentioned. Special attention is focused on a highly selective and sensitive technique of mass spectrometry and its application for identification of isoflavones and their glucosides in plants. Studies of interactions of isoflavones with cell receptors and a number of biologically active substances such as DNA and proteins are described. The reason for the presentation of the review was not to give a full overview of the presented topics but mainly to show modern and the most recent methods in the studies of isoflavones.
- MeSH
- chemické techniky analytické přístrojové vybavení metody MeSH
- isoflavony analýza chemie izolace a purifikace MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- isoflavony MeSH
Two polar analytes, 4(5)-methylimidazole (4-MeI) and 2-acetyl-4(5)-(1,2,3,4)-tetrahydroxybutyl-imidazole (THI), were extracted with supercritical carbon dioxide (CO2) modified with aqueous methanol. The method was applied to a roasted coffee powder with good recovery rates. Method efficiency was compared with that of solid-phase extraction using SCX Disc cartridges and validated for spiked solid matrix. The analytes were determined using isocratic liquid chromatography-mass spectrometry (LC/MS) on an Atlantis HILIC Silica column (150 x 2.1 mm, 3 microm) with 80% methanol and 20% 0.01 mol l-1 ammonium formate as the mobile phase. The limit of quantification was around 1.5 pg for 4-MeI and 2.0 pg for THI. The linearity of the calibration curves was satisfactory as indicated by correlation coefficients of >0.999. The coefficient of variation for the intra-day and inter-day precisions was <4% (n = 6). Accuracy was in the range 98-101%; recovery rates were > or = 98 and > or = 99% for THI and 4-MeI, respectively. Several samples of Arabica coffee from various locations and commercially available 'off-the-shelf' coffee products (Arabica/Robusta mixtures) were analysed to test the method.
- MeSH
- analýza potravin metody MeSH
- hmotnostní spektrometrie s elektrosprejovou ionizací metody MeSH
- imidazoly analýza izolace a purifikace MeSH
- káva chemie MeSH
- kontaminace potravin analýza MeSH
- superkritická fluidní chromatografie metody MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- validační studie MeSH
- Názvy látek
- 2-acetyl-4(5)-tetrahydroxybutylimidazole MeSH Prohlížeč
- 4-methylimidazole MeSH Prohlížeč
- imidazoly MeSH
- káva MeSH
Pressurised liquid extraction (PLE) was used in the extraction of three ketones of polycyclic aromatic hydrocarbons from the sample of a soil highly contaminated with polycyclic polyaromatic compounds. The choice of solvent was the only factor that considerably influenced the extraction efficiency of PLE under the conditions recommended in Method 3545A promulgated by the United States Environmental Protection Agency. The dichloromethane-ethanol solvent mixture was found to be the most efficient solvent. PLE using this mixture provided better recoveries of all analysed ketones relative to Soxhlet extraction.
- MeSH
- ketony izolace a purifikace MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí metody MeSH
- polycyklické aromatické uhlovodíky chemie MeSH
- půda analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- ketony MeSH
- polycyklické aromatické uhlovodíky MeSH
- půda MeSH
