electrolyte optimization
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Před deseti lety byly v časopise Critical Care publikovány výsledky randomizované prospektivní monocentrické práce zabývající se optimalizací hemodynamiky u rizikových pacientů podstupujících plánované nitrobřišní zákroky. Tento přehledový článek přináší kritické zhodnocení výsledků práce a dalšího vývoje v této problematice nazíraný s odstupem jedné dekády.
Ten years ago, the results of randomized prospective single-centrce study aimed to optimize hemodynamics in high-risk patients undergoing scheduled intra-abdominal procedures were published in Critical Care journal. This review article provides a critical assessment of the results of this work and further developments in this area, seen from a distance of one decade.
- Klíčová slova
- hemodynamická monitorace, studie SVVOPT,
- MeSH
- lidé MeSH
- peroperační monitorování metody MeSH
- peroperační péče MeSH
- pooperační komplikace prevence a kontrola MeSH
- prospektivní studie MeSH
- randomizované kontrolované studie jako téma MeSH
- tekutinová terapie * metody MeSH
- tepový objem fyziologie MeSH
- umělé dýchání MeSH
- vodní a elektrolytová rovnováha MeSH
- Check Tag
- lidé MeSH
We present a method for finely adjustable electroosmotic flow (EOF) velocity in cathodic direction for the optimization of separations in capillary electrophoresis. To this end, we use surface modification of the separation fused silica capillary by the covalently attached copolymer of acrylamide (AM) and 2-acrylamido-2-methyl-1-propanesulfonate (AMPS), that is, poly(AM-co-AMPS) or PAMAMPS. Coatings were formed by the in-capillary polymerization of a mixture of the neutral AM and anionic AMPS monomers premixed in various ratios in order to control the charge density of the copolymer. EOF mobility varies in the 0 to ∼40 × 10-9 m2 V-1 s-1 interval for PAMAMPS coatings ranging from 0 to 60 mol.% of charged AMPS monomer. For EOF in PAMAMPS-treated capillaries, we observed (i) a negligible dependence on pH in the 2-10 interval, (ii) a minor variance among background electrolytes (BGEs) in function of their components and (iii) its standard decrease with increasing ionic strength of the BGE. Interest in variable cathodic EOF was demonstrated by the amelioration of separation of two kinds of isomeric anionic analytes, that is, monosaccharides phosphates and helquat enantiomers, in counter-EOF mode.
In this article, optimization of BGE for simultaneous separation of inorganic ions, organic acids, and glutathione using dual C4 D-LIF detection in capillary electrophoresis is presented. The optimized BGE consisted of 30 mM 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid, 15 mM 2-amino-2-hydroxymethyl-propane-1,3-diol, and 2 mM 18-crown-6 at pH 7.2 and allowed simultaneous separation of ten inorganic anions and cations, three organic acids and glutathione in 20 min. The samples were injected hydrodynamically from both capillary ends using the double-opposite end injection principle. Sensitive detection of anions, cations, and organic acids with micromolar LODs using C4 D and simultaneously glutathione with nanomolar LODs using LIF was achieved in a single run. The developed BGE may be useful in analyses of biological samples containing analytes with differing concentrations of several orders of magnitude that is not possible with single detection mode.
- MeSH
- dechové testy metody MeSH
- design vybavení MeSH
- elektrická vodivost MeSH
- elektroforéza kapilární metody MeSH
- fluorescenční spektrometrie metody MeSH
- glutathion analýza izolace a purifikace MeSH
- ionty analýza izolace a purifikace MeSH
- kyseliny karboxylové analýza izolace a purifikace MeSH
- lidé MeSH
- limita detekce MeSH
- lineární modely MeSH
- reprodukovatelnost výsledků MeSH
- slzy chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This paper describes the results of the second-level testing of the simulation program Simul 5 Complex. We compare the published experimental results with the simulated migration behavior of the enantiomers at different pH and chiral selector concentration values and use the same optimization object function, separation selectivity, as the original papers. Simul 5 Complex proved to be a suitable tool for the prediction of the effective mobilities, separation selectivities, and migration order reversals in these pH-dependent and CD concentration dependent enantiomer separations. In addition, by performing simulations of four different separations systems (both real and model systems), Simul 5 Complex revealed the existence of unexpected and hitherto unexplained electromigration dispersion effects that were caused by the complexation process itself and could significantly impair the quality of the separations.
- MeSH
- chemické modely * MeSH
- dipeptidy chemie izolace a purifikace MeSH
- elektroforéza kapilární * MeSH
- elektrolyty MeSH
- koncentrace vodíkových iontů MeSH
- počítačová simulace MeSH
- software MeSH
- stereoizomerie MeSH
- tropany chemie izolace a purifikace MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Substancia L-cystín bola stanovovaná metódou kapilárnej izotachoforézy v dvoch elektrolytovýchsystémoch. Bola hodnotená presnosť, správnosť, linearita, robustnosť a selektivita ITP metódy.Výsledky ITP meraní boli porovnané s výsledkami získanými pomocou štandardných liekopisnýchmetód.
The compound L-cystine was determined using the method of capillary isotachophoresis in twoelectrolyte systems. Precision, correctness, linearity, robustness, and selectivity of ITP were evaluated.The results of ITP measurements were compared with the results obtained by means of thestandard pharmacopoeial methods.
Electroosmotic flow (EOF) plays a pivotal role in optimization of capillary electrophoresis (CE) separations of (bio)molecules and (bio)particles. EOF velocity is directly related to analysis time, peak resolution and separation efficiency. Here, we report a concept of charged polymer coatings of the inner fused silica capillary wall, which allows anodic EOF with mobility ranging from 0 to ∼(30-40) × 10-9 m2V-1s-1. The capillary wall is modified by covalently bound cationic copolymer poly(acrylamide-co-(3-acrylamidopropyl)trimethylammonium chloride) (PAMAPTAC) containing variable ratio of the charged monomer in the 0-60 mol. % interval. The EOF mobility showed minor variability with composition of background electrolyte (BGE) and pH in the 2-10 interval. The coatings were evaluated by CE-UV and nanospray CE-MS in the counter-EOF arrangement for a series of basic drug molecules in acetic acid based acidic BGE. Tunable EOF velocity was demonstrated as a useful tool for optimization of peak resolution, separation efficiency and migration time of analytes. Electrostatic repulsion of positively charged capillary surface was shown as beneficial for suppression of analyte adsorption, notably for hydrophobic cationic analytes.
- MeSH
- adsorpce MeSH
- elektroforéza kapilární * MeSH
- elektroosmóza * MeSH
- kationty MeSH
- polymery MeSH
- Publikační typ
- časopisecké články MeSH
A simple rule stating that the signal in conductivity detection in capillary zone electrophoresis is proportional to the difference between the analyte mobility and mobility of the background electrolyte (BGE) co-ion is valid only for systems with fully ionized electrolytes. In zone electrophoresis systems with weak electrolytes both conductivity signal and electromigration dispersion of analyte peaks depend on the conductivity and pH effects. This allows optimization of the composition of BGEs to give a good conductivity signal of analytes while still keeping electromigration dispersion near zero, regardless of the injected amount of sample. The demands to achieve minimum electromigration dispersion and high sensitivity in conductivity detection can be accomplished at the same time. PeakMaster software is used for inspection of BGEs commonly used for separation of sugars (carbohydrates, saccharides) at highly alkaline pH. It is shown that the terms direct and indirect conductivity detection are misleading and should not be used.
