Interestingly, even though the absorption maximum of prepared capped carbon quantum dots (CQDs) is 210 nm and the emission maximum is 392 nm, using capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) with excitation wavelength of 470 nm and long pass emission filter (510 nm) a signal was observed. Application of separation technique reviled presence of two different species, which corresponded to two well-resolved peaks present in the electropherogram. This fact is probably caused by presence of particles of different sizes.
Intoxikace metanolem může způsobit diagnostické potíže, pokud neexistuje údaj o požití závadné látky. V úvodu epidemie metanolových otrav v ČR v roce 2012 jsme se s negativní anamnézou konzumace alkoholu potýkali hned několikrát. Hladiny metanolu byly u těchto několika pacientů stopové, někdy dokonce nulové. Pacienti trpěli četnými přidruženými nemocemi, někteří z nich museli být během přijetí resuscitováni. Jednoduchá metoda stanovení hladiny kyseliny mravenčí nebyla v prvních dnech vlny otrav běžně dostupná. Intoxikace metanolem byla definitivně potvrzena v těchto případech až dodatečným vyšetřením kyseliny mravenčí v séru ve specializované laboratoři s odstupem několika dalších dnů. Tyto skutečnosti nás vedly k ověření možnosti detekce nadlimitní koncentrace formiátu v séru rychlým screeningovým vyšetřením. Analýza vzorků krevního séra, odebraných během léčby intoxikace metanolem, kapilární elektroforézou ukázala, že lze dobře monitorovat hladinu formiátu v séru jak před zahájením terapie, tak během ní. Klíčová slova: metanol – kyselina mravenčí – acidóza – kapilární elektroforéza – hemodialýza
Methanol intoxication can be difficult to diagnose, especially if there is no supporting evidence of ingestion of the toxic compound. At the begining of the methanol intoxication epidemic in the Czech Republic (2012) we faced a negative anamnesis of alcohol consumption several times. The measured levels of methanol in these patients were very low, sometimes methanol was even not detected. The patients were suffering from concomitant illnesses and some of them had to be resuscitated during admission. Simple screening methods able to detect formic acid were not available at the beginning of the epidemic. Eventually, methanol intoxication was confirmed a few days later in a specialized toxicological laboratory. Therefore, we tested a novel capillary electrophoretic method for the rapid screening of concentration of formic acid in the serum above its normal physiological range. Analysis of the serum of the patients intoxicated with methanol proved that monitoring of formate concentration in the serum with the newly developed method before and during the medical management is possible. Keywords: methanol – formic acid – acidosis – capillary electrophoresis – haemodialysis
- Klíčová slova
- kyselina mravenčí,
- MeSH
- acidóza etiologie patofyziologie terapie MeSH
- antidota terapeutické užití MeSH
- časná diagnóza MeSH
- časové faktory MeSH
- dialýza ledvin MeSH
- elektroforéza kapilární * metody statistika a číselné údaje využití MeSH
- ethanol aplikace a dávkování terapeutické užití MeSH
- fomepizol MeSH
- formiáty * krev metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- methanol * krev metabolismus otrava MeSH
- otrava diagnóza patofyziologie terapie MeSH
- péče o pacienty v kritickém stavu MeSH
- pyrazoly terapeutické užití MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- diagnostika, biomarker,
- MeSH
- elektroforéza kapilární statistika a číselné údaje využití MeSH
- financování organizované MeSH
- lidé MeSH
- moč MeSH
- nádory prostaty diagnóza klasifikace moč MeSH
- sarkosin analýza diagnostické užití moč MeSH
- stupeň závažnosti nemoci MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
CE with capacitively coupled contactless conductivity detection (C(4)D) was used to determine waste products of the nitrogen metabolism (ammonia and creatinine) and of biogenic inorganic cations in samples of human urine. The CE separation was performed in two BGEs, consisting of 2 M acetic acid + 1.5 mM crown ether 18-crown-6 (BGE I) and 2 M acetic acid + 2% w/v PEG (BGE II). Only BGE II permitted complete separation of all the analytes in a model sample and in real urine samples. The LOD values for the optimized procedure ranged from 0.8 microM for Ca(2+) and Mg(2+) to 2.9 microM for NH(4)(+) (in terms of mass concentration units, from 7 microg/L for Li(+) to 102 microg/L for creatinine). These values are adequate for determination of NH(4)(+), creatinine, Na(+), K(+), Ca(2+) and Mg(2+) in real urine samples.
CZE has been applied for determination of acid-base dissociation constants (pKa) of ionogenic groups of newly synthesized amino- and (amino)guanidinopurine nucleotide analogs, such as acyclic nucleoside phosphonate, acyclic nucleoside phosphonate diesters and other related compounds. These compounds bear characteristic pharmacophores contained in various important biologically active substances, such as cytostatics and antivirals. The pKa values of ionogenic groups of the above compounds were determined by nonlinear regression analysis of the experimentally measured pH dependence of their effective electrophoretic mobilities. The effective mobilities were measured by CZE performed in series of BGEs in a broad pH range (3.50-11.25), at constant ionic strength (25 mM) and temperature (25 degrees C). pKa values were determined for the protonated guanidinyl group in (amino)guanidino 9-alkylpurines and in (amino)guanidinopurine nucleotide analogs, such as acyclic nucleoside phosphonates and acyclic nucleoside phosphonate diesters, for phosphonic acid to the second dissociation degree (-2) in acyclic nucleoside phosphonates of amino and (amino)guanidino 9-alkylpurines, and for protonated nitrogen in position 1 (N1) of purine moiety in acyclic nucleoside phosphonates of amino 9-alkylpurines. Thermodynamic pKa of protonated guanidinyl group was estimated to be in the range of 7.75-10.32, pKa of phosphonic acid to the second dissociation degree achieved values of 6.64-7.46, and pKa of protonated nitrogen in position 1 of purine was in the range of 4.13-4.89, depending on the structure of the analyzed compounds.
This article investigates the principles of stacking of analytes by a zone of a bulk sample component that possesses one hybrid boundary. The model system investigated comprises a transient stacking zone in a BGE where the rear boundary of this zone is a hybrid one. A theoretical description of such a system is given, and general rules and mathematical criteria for quantitative stacking are presented. These criteria are based on comparison of migration velocities of analytes to be stacked and velocities of the boundaries of the stacking zone. It is shown that the presence of a hybrid boundary brings about additional constraints for stacking of analytes due to the presence of the sharp part of the hybrid boundary that migrates faster than regular sharp boundary of this zone. An experimental example related to the described theory is also shown.
This article investigates the principles of stacking of analytes by a zone of a bulk sample component that possesses one hybrid boundary. The model system investigated comprises a transient stacking zone in a BGE where the rear boundary of this zone is a hybrid one. A theoretical description of such a system is given, and general rules and mathematical criteria for quantitative stacking are presented. These criteria are based on comparison of migration velocities of analytes to be stacked and velocities of the boundaries of the stacking zone. It is shown that the presence of a hybrid boundary brings about additional constraints for stacking of analytes due to the presence of the sharp part of the hybrid boundary that migrates faster than regular sharp boundary of this zone. An experimental example related to the described theory is also shown.
- MeSH
- antigen CA-125 krev MeSH
- elektroforéza kapilární metody statistika a číselné údaje MeSH
- finanční podpora výzkumu jako téma MeSH
- fosfolipidy diagnostické užití chemie krev MeSH
- karcinom diagnóza MeSH
- lidé MeSH
- nádorové biomarkery krev MeSH
- nádory vaječníků diagnóza MeSH
- senzitivita a specificita MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
Molybdate was examined as a complex-forming additive to the CE background electrolytes (BGE) to affect the selectivity of separation of polyhydric phenols such as flavonoids (apigenin, hyperoside, luteolin, quercetin and rutin) and hydroxyphenylcarboxylic acids (ferulic, caffeic, p-coumaric and chlorogenic acid). Effects of the buffer concentrations and pH and the influence of molybdate concentration on the migration times of the analytes were investigated. In contrast to borate (which is a buffering and complex-forming agent generally used in CE at pH > or =9) molybdate forms more stable complexes with aromatic o-dihydroxy compounds and hence the complex-formation effect is observed at considerably lower pH. Model mixtures of cinnamic acid, ferulic acid, caffeic acid and 3-hydroxycinnamic acid were separated with 25 mM morpholinoethanesulfonic acid of pH 5.4 (adjusted with Tris) containing 0.15 mM sodium molybdate as the BGE (25 kV, silica capillary effective length 45 cm x 0.1mm I.D., UV-vis detection at 280 nm). With 25 mM 2-hydroxy-3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulphonic acid/Tris of pH* 7.4 containing 2mM sodium molybdate in aqueous 25% (v/v) methanol as the BGE mixtures of all the above mentioned flavonoids, p-coumaric acid and chlorogenic acid could be separated (the same capillary as above, UV-vis detection at 263 nm). The calibration curves (analyte peak area versus concentration) were rectilinear (r>0.998) for approximately 8-35 microg/ml of an analyte (with 1-nitroso-2-naphthol as internal standard). The limit of quantification values ranged between 1.1 mg l(-1) for p-coumaric acid and 2.8 mg l(-1) for quercetin. The CE method was employed for the assay of flavonoids in medicinal plant extracts. The R.S.D. values ranged between 0.9 and 4.7% (n=3) when determining luteolin (0.08%) and apigenin (0.92%) in dry Matricaria recutita flowers and rutin (1.03%) and hyperoside (0.82%) in dry Hypericum perforatum haulm. The recoveries were >96%.
- MeSH
- biomedicínský výzkum MeSH
- elektroforéza kapilární statistika a číselné údaje MeSH
- elektroforéza sérových bílkovin metody statistika a číselné údaje MeSH
- elektroforéza v agarovém gelu statistika a číselné údaje MeSH
- referenční standardy MeSH
- sérové globuliny izolace a purifikace MeSH
- sérový albumin izolace a purifikace MeSH
- Publikační typ
- hodnotící studie MeSH
- Geografické názvy
- Česká republika MeSH
