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Über die Verbreitung von Flavonoiden bei pleurokarpen Laubmoosen II. Apigenin and Apigenin-7-rhamnoglucosid bei Pleurozium schreberi (Willd.) Mitt.
1980
Summary 12 species of pleurocarpous mosses have been investigated as to their content of flavonoids. Flavonoid tests on 11 species have given negative results. Only one species, Pleurozium schreberi , contains three flavonoids. They were purified by means of paper chromatography. Two of them are by chromatography, acid hydrolysis and absorption spectrum identical with apigenin and apigenin-7-rhamnoglucoside. The third flavonoid is as yet unidentified. Qualitative hydrolysis yields apigenin. The chemotaxonomic importance of the results is briefly discussed.
Prediction of the curing time of Spanish hams using peptide profiles established by capillary zone electrophoresis
2009
Abstract A capillary zone electrophoresis procedure for the prediction of curing time of Spanish hams using peptide profiles has been developed. Excellent resolution between the seven peptide peaks was achieved within 30 min analysis time with a BGE containing 60 mM MgSO 4 and 50 mM phosphate at pH 2.5. Using hams with curing times of 6, 8 and 12 months, both linear discriminant analysis (LDA) and multiple linear regression (MLR) models were constructed. In both cases, two different normalisation procedures of the peak areas were compared. Using LDA, all the ham samples corresponding to the three categories were correctly classified. Using MLR, the ham curing time could be predicted with av…
Determination of optical purity of phosphonic acid analogues of aromatic amino acids by capillary electrophoresis with alpha-cyclodextrin.
2000
A simple and efficient method for the determination of enantiomeric purity of structurally diverse phosphonic and phosphinic acid analogues of phenylalanine and phenylglycine using capillary electrophoresis is presented. These preliminary studies indicated that the enantiomer separation is strongly dependent on the structure of the aminophosphonic acid.
Gas chromatography of homologous esters
1984
Abstract The gas chromatographic retention behaviour of the butanoyl and 2-, 3- and 4-chlorobutanoyl esters of C 3 —C 5 saturated aliphatic branched-chain and unsaturated C 3 —C 6 alcohols on SE-30 and OV-351 glass capillary columns operated iso-thermally at several temperatures is reported. Retention index increments at 80, 120 and 160°C show the effects of chain branching and the olefinic and acetylenic unsaturation in the alkyl chain and the effect of the position of the chlorine substituent in the acyl chain. The results are compared with the behaviour of the corresponding n -alkyl esters and the chlorinated propanoyl esters.
Fast determination of prominent carotenoids in tomato fruits by CEC using methacrylate ester-based monolithic columns.
2007
In this study, the major carotenoids (beta-carotene and lycopene) present in tomato fruits were analyzed by CEC with a methacrylate ester-based monolithic column. The effects of the porogenic solvent ratio, and the hydrophobicity of bulk monomer employed were examined on carotenoids separations. A fast separation of these analytes was achieved in less than 5.0 min in a mobile phase containing 35% THF, 30% ACN, 30% methanol, and 5% of a 5 mM Tris aqueous buffer, pH 8, with lauryl methacrylate-based monoliths. The CEC method was evaluated in terms of detection limit and reproducibility (retention time, area, and column preparation) with values below 1.6 microg/mL and 7.2%, respectively. The p…
In-tube solid-phase microextraction coupled by in valve mode to capillary LC-DAD: Improving detectability to multiresidue organic pollutants analysis…
2009
Abstract A simple and fast capillary chromatographic method has been developed to identify and quantify organic pollutants at sub-ppb levels in real water samples. The major groups of pesticides (organic halogens, organic phosphorous, and organic nitrogen compounds), some hydrocarbons (polycyclic aromatic hydrocarbons), phthalates and some phenols such as phenol and bisphenol A (endocrine disruptors) were included in this study. The procedure was based on coupling, in-tube solid-phase microextraction (IT-SPME) by using a conventional GC capillary column (95% methyl–5% phenyl substituted backbone, 80 cm × 0.32 mm i.d., 3 μm film thickness) in the injection valve to capillary liquid chromatog…
Chemical degradation products of lignin and humic substances part I Synthesis, structure verification and gas chromatographic separation of chlorinat…
1993
Abstract Chlorinated vanillins (4-hydroxy-3-methoxybenzaldehydes) and syringaldehydes (3,5-dimethoxy-4-hydroxy-benzaldehydes) were synthesized and their purities and structures were examined by quartz capillary gas chromatography and mass spectrometry. The detailed procedures for the synthesis, gas chromatographic separation and mass spectroscopic features are presented.
The impact of Pleurotus ostreatus on organic matter transformation processes.
2012
This study showed the effect of Pleurotus ostreatus on the external organic matter (OM) transformation processes. The kinetics of these changes were determined. The experiment was conducted as 42-day pot experiment done in four combinations (with four replications). The four combinations of different substrates were: (1) organic, (2) composted hay, (3) organic soil + composted hay, (4) organic soil + composted hay + lead. The study results showed that P. ostreatus had the ability to transform external OM as well as metal–organic complexes. These transformations were reflected in the constant rate of characterized changes and correlation coefficients. The study also indicated the direction o…
Lauroyl peroxide as thermal initiator of lauryl methacrylate monolithic columns for CEC
2008
The preparation of lauryl methacrylate (LMA)-based monolithic columns for CEC using lauroyl peroxide (LPO) as thermal initiator of polymerization has been investigated. The influence of initiator amount and composition of porogenic solvent on the physical and electrochromatographic properties of the resulting LMA-based monoliths was evaluated. A comparison with LMA-based columns thermally polymerized with AIBN was performed. At a given porogenic solvent composition, LMA stationary phases initiated with LPO showed higher permeabilities and better efficiency values than those prepared using AIBN as initiator. The optimum polymerization mixture found for LPO initiator provided a minimum plate …
Determination of major carotenoids in vegetables by capillary electrochromatography.
2006
A simple and rapid method for the isocratic separation and determination of carotenoids (carotenes and xanthophylls) in vegetables by CEC is described. The capillary column (100 microm ID, 25 cm effective length) was packed with 3 microm Hypersil ODS particles. The optimized mobile phase contained 60% ACN, 35% THF and 5% of a 5 mM Tris aqueous buffer of pH 8. beta-Carotene, lycopene and lutein were separated with efficiencies of 66 000-128 000 plates/m within a short time (less than 12 min for the last peak eluted, 13/13'-cis-beta-carotene). An excellent resolution of the three carotenoids, as well as partial resolution of their geometrical isomers, was achieved. Application to the determin…