high performance liquid chromatography with electrochemical detection
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- MeSH
- chromatografie kapalinová statistika a číselné údaje MeSH
- elektrochemie MeSH
- hydrolýza metody MeSH
- sulfonamidy analýza MeSH
- Publikační typ
- přehledy MeSH
The objective of this study was the determination of 25 phenolic compounds in different mead samples (honeywines) using high performance liquid chromatography (HPLC) with coulometric-array detection and in case of hydroxymethylfurfural with UV detection. Our method was optimized in respect to both the separation selectivity of individual phenolic compounds and the maximum sensitivity with the electrochemical detection. The method development included the optimization of mobile phase composition, the pH value, conditions of the gradient elution and the flow rate using a window-diagram approach. The developed method was used for the determination of limits of detection and limits of quantitation for individual compounds. The linearity of calibration curves, accuracy and precision (intra- and inter-day) at three concentration levels (low, middle and high concentration range) were verified. Mead samples were diluted with the mobile phase at 1:1 to 1:50 ratio depending on the concentration and filtered through a PTFE filter without any other sample pre-treatment. Phenolic compounds concentration was determined in 50 real samples of meads and correlated with meads composition and hydroxymethylfurfural concentration. The most frequently occurred compounds were protocatechuic acid and vanillic acid (both of them were present in 98% samples), the least occurred compounds were (+)-catechin (10% samples) and sinapic acid (12% samples). Vanillin and ethylvanillin, which are used as artificial additives for the taste improvement, were found in 60% and 42% samples, respectively. Hydroxymethylfurfural concentration, as an indicator of honey quality, was in the range from 2.47 to 158 mg/L. Our method is applicable for the determination of 25 phenolic compounds in mead, honey and related natural samples.
- MeSH
- 2-furaldehyd analogy a deriváty analýza chemie MeSH
- fenoly analýza chemie MeSH
- financování organizované MeSH
- molekulární struktura MeSH
- nápoje analýza MeSH
- reprodukovatelnost výsledků MeSH
- spektrofotometrie ultrafialová metody MeSH
- víno analýza MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
A simple, fast and sensitive HPLC method employing dual-channel coulometric detection for the determination of repaglinide in human plasma is presented. The assay involved extraction of repaglinide by ethyl acetate and isocratic reversed-phase liquid chromatography with dual-channel coulometric detection. The mobile phase composition was 50mM disodium hydrogen phosphate/acetonitrile (60:40, v/v), pH of the mobile phase 7.5 set up with phosphoric acid. For all analyses, the first cell working potential was +380mV, the second was +750mV (vs. Pd/H(2)). Calibration curve was linear over the concentration range of 5-500nmolL(-1). Rosiglitazone was used as an internal standard. The limit of detection (LOD) was established at 2.8nmolL(-1), and the lower limit of quantification (LLOQ) at 8.5nmolL(-1). The developed method was applied to human plasma samples spiked with repaglinide at therapeutical concentrations. It was confirmed that the method is suitable for pharmacokinetic studies or therapeutic monitoring.
- MeSH
- elektrochemické techniky metody MeSH
- hypoglykemika krev chemie MeSH
- karbamáty krev chemie MeSH
- kolorimetrie metody MeSH
- koncentrace vodíkových iontů MeSH
- lidé MeSH
- lineární modely MeSH
- piperidiny krev chemie MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- thiazolidindiony analýza MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
