Q124638986
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Electromembrane extraction (EME) and CE with capacitively coupled contactless conductivity detection (CE-C(4) D) was applied to rapid and sensitive determination of perchlorate in drinking water and environmental samples. Porous polypropylene hollow fiber impregnated with 1-heptanol acted as a supported liquid membrane (SLM) and perchlorate was transported and preconcentrated in the fiber lumen on application of electric field. High selectivity of perchlorate determination and its baseline separation from major inorganic anions was achieved in CE-C(4) D using background electrolyte solution consisting of 7.5 mM L-histidine and 40 mM acetic acid at pH 4.1. The analytical method showed excellent parameters in terms of reproducibility; RSD values for migration times and peak areas at a spiked concentration of 15 μg/L of perchlorate (US EPA recommended limit for drinking water) were below 0.2 and 8.7%, respectively, in all examined water samples. Linear calibration curves were obtained for perchlorate in the concentration range 1-100 μg/L (r(2) ≥0.999) with limits of detection at 1 μg/L for tap water and at 0.25-0.35 μg/L for environmental and bottled potable water samples. Recoveries at 15 μg/L of perchlorate were between 95.9 and 106.7% with minimum and maximum recovery values for snow and bottled potable water samples, respectively.
- MeSH
- chemická frakcionace přístrojové vybavení metody MeSH
- déšť chemie MeSH
- elektrická vodivost MeSH
- elektroforéza kapilární metody MeSH
- elektrolyty chemie MeSH
- heptanol chemie MeSH
- histidin chemie MeSH
- koncentrace vodíkových iontů MeSH
- kyselina octová chemie MeSH
- membrány umělé MeSH
- perchloráty analýza izolace a purifikace MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
An overview of the developments of capacitively coupled contactless conductivity detection in CE and related techniques over approximately the last 2 years is given. The method has seen strong growth, and diverse new applications are being reported. Besides more advanced techniques on conventional capillaries, these include further developments of detection on lab-on-chip devices as well as in miniaturized chromatographic systems and some methods not involving separations. An increasing number of reports are based on the now readily available commercial detectors, but, while few publications on fundamental studies have appeared recently, interesting new approaches on creating low cost devices have also appeared.
A simple analytical system using disposable, open-tubular ion exchange clean-up precolumns coupled in-line to capillary electrophoresis for direct injection of biological samples is presented. The clean-up precolumns were prepared from fused silica capillaries by thermally initiated layer-by-layer polymerization of poly(butadiene-maleic acid) (PBMA) directly on the capillary wall. Typically, 6 cm long precolumns with 4-layers of PBMA were used for sample pretreatment. A robust and reproducible coupling between the precolumn (75 μm ID) and the analytical capillary (50 μm ID) was achieved using an inexpensive, commercially available low dead volume union. No extra dispersion of the analyte zones was observed. Proteins and other high molecular weight compounds from biological sample matrices were retained on the cation-exchanger sites of the precolumn, which eliminated their adsorption on analytical capillary walls and ensured stable electroosmotic flow and migration times of target analytes. Unretained small inorganic cations migrated freely into the analytical capillary for separation and detection. Applicability of the sample clean-up procedure was proved by determination of major inorganic cations in blood serum and plasma samples using capillary electrophoresis with contactless conductivity detection. Separations were performed in background electrolyte solution consisting of 15 mM L-arginine, 12.5 mM maleic acid, 3 mM 18-crown-6 at pH 5.5 and repeatabilities of migration times and peak areas were below 1.5% and 7.3%, respectively. Less than 1 μL of biological sample was required for injection.
- MeSH
- butadieny chemie MeSH
- chromatografie iontoměničová metody MeSH
- draslík krev izolace a purifikace MeSH
- elektrická vodivost MeSH
- elektroforéza kapilární MeSH
- hořčík krev izolace a purifikace MeSH
- kationty krev chemie izolace a purifikace MeSH
- kovy krev chemie izolace a purifikace MeSH
- lidé MeSH
- maleáty chemie MeSH
- polymery chemie MeSH
- reprodukovatelnost výsledků MeSH
- sodík krev izolace a purifikace MeSH
- vápník krev izolace a purifikace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Micro-electrodialysis (μED) and CE were combined for rapid pretreatment and subsequent determination of inorganic cations in biological samples. Combination of μED with CE greatly improved the analytical performance of the latter as the adsorption of high molecular weight compounds present in real samples on the inner capillary wall was eliminated. Fifty microliter of 80-fold diluted human body fluids such as plasma, serum and whole blood was used in the donor compartment of the μED system requiring less than 1 μL of the original body fluid per analysis. Inorganic cations that migrated through a cellulose acetate dialysis membrane with molecular weight cut-off value of 500 Da were collected in the acceptor solution and were then analyzed using CE-C⁴D. Baseline separation of inorganic cations was achieved in a BGE solution consisting of 12.5 mM maleic acid, 15 mM L-arginine and 3 mM 18-crown-6 at pH 5.5. Repeatability of the CE-C⁴D method was better than 0.5% and 2.5% for migration times and peak areas, respectively; limits of detection of all inorganic cations in the presence of 2 mM excess of Na(+) were around 1 μM and calibration curves were linear with correlation coefficients better than 0.998. Repeatability of the sample pretreatment procedure was calculated for six independent electrodialysis runs of artificial and real samples and was better than 11.8%. Recovery values between 96.3 and 110% were achieved for optimized electrodialysis conditions of standard solutions and real samples; lifetime of the dialysis membranes for pretreatment of real samples was estimated to 100 runs.
- MeSH
- elektrická vodivost MeSH
- elektroforéza kapilární metody MeSH
- elektrolyty chemie MeSH
- kationty analýza krev MeSH
- krev metabolismus MeSH
- krevní plazma metabolismus MeSH
- lidé MeSH
- mikrodialýza přístrojové vybavení MeSH
- reprodukovatelnost výsledků MeSH
- roztoky chemie MeSH
- sérum metabolismus MeSH
- tělesné tekutiny chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Separation techniques, such as electrodialysis, electroextraction, electro-membrane extraction and extraction across phase interfaces, are reviewed and discussed as methods for sample cleanup and preconcentration. This survey clearly shows that electromigration of ionic species across phase interfaces, especially across supported liquid membranes, may be very selective and is strongly dependent on the chemical composition of these interfaces. Thus, electric field-enhanced transport across chemically tailored liquid membranes may open new perspectives in preparative analytical chemistry. This review offers comprehensive survey of related literature and discussion of the topic, which may stimulate interest of experts and practitioners in bioanalysis.
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Vydání 1. 23 stran : barevné ilustrace ; 21 cm
Brožura se zaměřuje na výzkumnou činnost Ústavu analytické chemie AV ČR. Určeno odborné veřejnosti.; Přehled vybraných výzkumných směrů na Ústavu analytické chemie AV ČR. Každé z pěti vědeckých oddělení ústavu představuje vybrané téma ze své činnosti.
- Klíčová slova
- Praha (Česko),
- MeSH
- akademie a ústavy MeSH
- analytická chemie MeSH
- chemie dějiny MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- věda MeSH
- výzkum MeSH
- Check Tag
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- Geografické názvy
- Česká republika MeSH
- Konspekt
- Analytická chemie
- NLK Obory
- chemie, klinická chemie
- věda a výzkum
- NLK Publikační typ
- brožury
