The review presents an evaluation of the development of on-line, at-line and in-line sample treatment coupled with capillary and microchip electrophoresis over the last 10 years. In the first part, it describes different types of flow-gating interfaces (FGI) such as cross-FGI, coaxial-FGI, sheet-flow-FGI, and air-assisted-FGI and their fabrication using molding into polydimethylsiloxane and commercially available fittings. The second part deals with the coupling of capillary and microchip electrophoresis with microdialysis, solid-phase, liquid-phase, and membrane based extraction techniques. It mainly focuses on modern techniques such as extraction across supported liquid membrane, electroextraction, single drop microextraction, head space microextraction, and microdialysis with high spatial and temporal resolution. Finally, the design of sequential electrophoretic analysers and fabrication of SPE microcartridges with monolithic and molecularly imprinted polymeric sorbents are discussed. Applications include the monitoring of metabolites, neurotransmitters, peptides and proteins in body fluids and tissues to study processes in living organisms, as well as the monitoring of nutrients, minerals and waste compounds in food, natural and wastewater.

• Klíčová slova
• Capillary electrophoresis, Electromembrane extraction, Flow-gating interface, Liquid-phase extraction, Microchip electrophoresis, Microdialysis, On-line coupling, Sequential analysis, Solid-phase extraction,
• MeSH
• elektroforéza kapilární metody   MeSH
• elektroforéza mikročipová * metody   MeSH
• mikrodialýza MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

An on-line coupled capillary isotachophoresis-capillary zone electrophoresis method for the determination of glycyrrhizin in liqueurs is described. The optimised electrolyte system was 5 mM HCl+11 mM epsilon-aminocaproic acid+0.05% hydroxyethylcellulose+30% methanol (leading electrolyte), 5 mM caproic acid+30% methanol (terminating electrolyte) and 20 mM caproic acid+10 mM histidine+0.1% hydroxyethylcellulose+30% methanol (background electrolyte). Method characteristics, i.e., linearity (20-500 ng/ml), accuracy (recovery 99+/-4%), intra-assay repeatability (2%), intermediate repeatability (3.8%) and detection limit (8 ng/ml) were determined. Speed of analysis, low laboriousness, high sensitivity and low-running cost are the typical attributes of the capillary isotachophoresis-capillary zone electrophoresis method. Developed method was successfully applied to analysis of liqueurs with liquorice extract and some foods (sweets and food supplements) containing liquorice. Found levels of glycyrrhizin in liqueurs, sweets and food supplements varied between 1-16 mg/l, 850-1050 mg/kg and 1.6-1.8 g/kg, respectively.

• MeSH
• alkoholické nápoje analýza   ekonomika   MeSH
• analýza potravin ekonomika   metody   MeSH
• elektroforéza kapilární metody   MeSH
• elektroforéza metody   MeSH
• Glycyrrhiza chemie   MeSH
• kalibrace MeSH
• konduktometrie MeSH
• kyselina glycyrrhizinová analýza   chemie   MeSH
• molekulární struktura MeSH
• on-line systémy * MeSH
• referenční standardy MeSH
• reprodukovatelnost výsledků MeSH
• senzitivita a specificita MeSH
• studie proveditelnosti MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyselina glycyrrhizinová MeSH

The combination of capillary isotachophoresis (ITP) and capillary zone electrophoresis (CZE) in the column coupling configuration was optimized in a mode where the electrolyte for the CZE step is different from the leading and terminating ITP electrolytes. Two colored markers, picric acid and 1-nitroso-2-naphthol, were used for exact timing of the transfer of isotachophoretically stacked analyte zones into the CZE column and for the control of the residual amount of the leading and terminating ITP electrolytes entering the CZE capillary together with the analytes, thus controlling the duration of transient ITP migration in the CZE capillary and ensuring good separation of the analytes and reproducibility of the migration times (relative standard deviations 1%). ITP-CZE was applied to the simultaneous assay of several cinnamic acid derivatives and flavonoids in methanolic extracts of Sambucus flowers and Crataegus leaves and flowers. The preconcentrating and cleansing effect of the ITP step allowed injection of relatively large sample volumes (30 microL). The limits of detection were approximately 20-50 ng x mL(-1) and 100 ng x mL(-1) for the acids and flavonoids, respectively ( thick similar 200-times lower compared to conventional CE) with spectrophotometric detection at 254 nm. The ITP-CZE exhibited satisfactory linearity and precision when using CZE buffer of pseudo "pH" 9.0; 1-nitroso-2-naphthol was employed as the internal standard. The separation took approximately 35 min. The ITP-CZE results for rutin, hyperoside, and vitexin-2-O"-rhamnoside were in good accordance with those obtained previously by high-performance liquid chromatography.

• MeSH
• elektroforéza kapilární metody   MeSH
• elektroforéza metody   MeSH
• elektrolyty MeSH
• fenoly analýza   MeSH
• rostlinné extrakty chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• elektrolyty MeSH
• fenoly MeSH
• rostlinné extrakty MeSH

Some methodological aspects of an on-line combination of capillary zone electrophoresis with mass spectrometric detection (CZE-QqQ-MS) were studied in this work as well as the possibilities of using this combination for analysis of the high-molecular mass compounds present in multi-component matrices. All experiments using an on-line combination of capillary electrophoresis with mass spectrometric detection were carried out in cationic mode in covalently-coated capillary. The optimised electrolyte system consisted of 100 mmol/L formic acid. Prior to the CZE-QqQ-MS analysis, an extraction of lysozyme from cheese samples using 1 mol/L of acetic acid was performed. The LOD was 3.6 mg lysozyme per kg and the LOQ was 10.9 mg lysozyme per kg. The concentration range of the lysozyme determined in four cheese samples analysed in this work was from 0.5 to 3.3g of lysozyme per kg. The values of the relative standard deviations thus obtained were from 4.6% to 9.3% depending on the cheese sample.

• Klíčová slova
• Capillary zone electrophoresis, Cheese, Lysozyme, Mass spectrometry, Multi-component matrices,
• MeSH
• elektroforéza kapilární metody   MeSH
• hmotnostní spektrometrie metody   MeSH
• kur domácí MeSH
• muramidasa analýza   MeSH
• potravinářské konzervační látky analýza   MeSH
• sýr analýza   MeSH
• vaječné proteiny analýza   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• Názvy látek
• muramidasa MeSH
• potravinářské konzervační látky MeSH
• vaječné proteiny MeSH

Free sucrose, lactose, galactose, glucose and fructose were determined in yoghurts, milk and honey using on-line coupling of capillary electrophoresis with microdialysis. The dairy products were diluted 50-fold with 10 mmol/L NaOH and sampled using laboratory-made microdialysis probes. The microdialysate was brought to the entrance of the electrophoretic capillary and the coupling consisted in a polydimethylsiloxane (PDMS) cross connector working in the flow-gating interface regime. The electrophoretic analysis was performed in 50 mmol/L NaOH (pH 12.6) background electrolyte, where baseline separation of the five saccharides was achieved in 3.5 min. The LOQs varied in the range 2.3-7.3 mg/L, the number of separation plates varied between 176,000 plates/m for glucose to 326,000 plates/m for galactose and the relative standard deviation (RSD) for ten consecutive analyses of fruit yoghurt was 0.2% for the migration time and 4.4-7.6% for the peak area.

• Klíčová slova
• Contactless conductivity detection, Flow-gating interface, Food analysis, Polydimethylsiloxane, Sequence analysis,
• MeSH
• elektroforéza kapilární * MeSH
• jogurt analýza   MeSH
• med analýza   MeSH
• mikrodialýza * MeSH
• Publikační typ
• časopisecké články MeSH

The on-line combination of capillary zone electrophoresis (CZE) with capillary isotachophoresis (ITP) increases significantly the separation capability and sensitivity of capillary electrophoresis. This technique was used for separation and quantification of fourteen selected natural constituents in red wine belonging to flavonoids and phenolic acids. The leading electrolyte (LE) in the ITP pre-separation step was 10 mM HCl of pH* 7.2 with Tris as counterion, the terminating electrolyte (TE) was 50 mM boric acid of pH* 8.2 (adjusted with barium hydroxide). The background electrolyte in the electrophoretic step contained 25 mM beta-hydroxy-4-morpholinopropanesulfonic acid (MOPSO), 50 mM Tris, 15 mM boric acid and 5 mM beta-cyclodextrin of pH* 8.5. The content of methanol in all electrolytes was 20% (v/v). For exact timing of the transfer of isotachophoretically stacked analyte zones into the CZE column and for the control of the residual amount of leading and terminating ITP electrolytes picric acid was used as coloured marker. The R.S.D. values (n = 6) ranged between approximately 0.1% (for 0.25 microg ml(-1) rutin) and approximately 11% (for 0.25 microg ml(-1) of quercitrin). Detection limits were 30 ng mi(-1) for phenolic acids, quercitrin and rutin, 100 ng ml(-1) for quercetin, kaempferol and epicatechin and 250 ng ml(-1) for catechin. A single analysis took 45 min.

• MeSH
• elektroforéza kapilární metody   MeSH
• elektroforéza metody   MeSH
• fenoly analýza   MeSH
• koncentrace vodíkových iontů MeSH
• reprodukovatelnost výsledků MeSH
• senzitivita a specificita MeSH
• víno analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fenoly MeSH

We present a simple and sensitive method for the determination of patulin at µg·kg-1 level in apple-based products. Our method relies on the application of an in-line molecularly imprinted polymer solid-phase extraction microcartridge in capillary electrophoresis coupled with mass spectrometry. Capillary zone electrophoresis method has been developed and parameters affecting the in-line process have been carefully optimized. Validation parameters were assessed for patulin, giving LOQ of 1 µg·kg-1 and linearity range 1-100 µg·kg-1 with R2 ≥ 0.997. The LOQ was below the maximum content of patulin requested by the European Union in this type of products. The precision of the peak area and the migration time were less than 14.9 and 1.6%, respectively. Patulin has been analyzed in the presence of 5-hydroxymethylfurfural, which is the main interference in this kind of matrix. The method was applied to assay patulin content in various apple-based products.

• Klíčová slova
• Capillary electrophoresis, In-line preconcentrator, Mass spectrometry, Molecularly imprinted polymer, Mycotoxin, Patulin,
• MeSH
• 2-furaldehyd analogy a deriváty   chemie   MeSH
• analýza potravin metody   MeSH
• elektroforéza kapilární metody   MeSH
• extrakce na pevné fázi metody   MeSH
• kontaminace potravin analýza   MeSH
• limita detekce MeSH
• Malus chemie   MeSH
• molekulový imprinting MeSH
• patulin analýza   MeSH
• polymery chemie   MeSH
• průmysl zpracování potravin MeSH
• tandemová hmotnostní spektrometrie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 2-furaldehyd MeSH
• 5-hydroxymethylfurfural MeSH Prohlížeč
• patulin MeSH
• polymery MeSH

A new approach is described for highly sensitive chiral analyses by capillary zone electrophoresis, based on using an on-line combination of two capillaries filled with either chiral selective or achiral background electrolytes (BGE). Thus, the BGEs are selected in such a way that the first capillary provides optimum chiral selectivity and the second one optimum detection sensitivity. Direct chiral separations of enantiomers of mandelic, m-methoxymandelic, 3-phenyllactic and 3-indolelactic acids served as a model example for testing the approach proposed. The analyses were performed in a BGE containing acetate as a coion and L-OH-proline or aspartame as a chiral selector. For high sensitive analyses, an arrangement containing on-line combined chiral and achiral media were tested in one or two capillaries coupled via a bifurcation block. A detection limit as low as 10(-18) moles was reached in the column-coupling system when the direct chiral separation was performed in the first capillary, filled with 20 mM acetate buffer, pH 4.4, containing 8 mM Cu (II) and 16 mM aspartame (L-aspartyl-L-phenylalanine methylester) and separated enantiomers were detected in the second capillary, filled with 20 mM acetate buffer, pH 3.1. The principle described is of general use in cases where the separation and detection of analytes in question require mutually different BGEs to reach the optimum selectivity and sensitivity, respectively.

• MeSH
• aspartam chemie   MeSH
• elektroforéza kapilární přístrojové vybavení   metody   MeSH
• elektrolyty * MeSH
• indoly chemie   MeSH
• kyseliny mandlové chemie   MeSH
• laktáty chemie   MeSH
• měď chemie   MeSH
• senzitivita a specificita MeSH
• stereoizomerie * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 3-phenyllactic acid MeSH Prohlížeč
• aspartam MeSH
• elektrolyty * MeSH
• indole-3-lactic acid MeSH Prohlížeč
• indoly MeSH
• kyseliny mandlové MeSH
• laktáty MeSH
• měď MeSH

A coaxial flow-gating interface is described in which the separation capillary passes through the sampling capillary. Continuous flow of the sample solution flowing out of the sampling capillary is directed away from the injection end of the separation capillary by counter-current flow of the gating solution. During the injection, the flow of the gating solution is interrupted, so that a plug of solution is formed at the inlet into the separation capillary, from which the sample is hydrodynamically injected. Flow-gating interfaces are originally designed for on-line connection of capillary electrophoresis with analytical flow-through methods. The basic properties of the described coaxial flow-gating interface were obtained in a simplified arrangement in which a syringe pump with sample solution has substituted analytical flow-through method. Under the optimized conditions, the properties of the tested interface were determined by separation of K+ , Ba2+ , Na+ , Mg2+ and Li+ ions in aqueous solution at equimolar concentrations of 50 μM. The repeatability of the migration times and peak areas evaluated for K+ , Ba2+ and Li+ ions and expressed as relative standard deviation did not exceed 1.4%. The interface was used to determine lithium in mineral water and taurine in an energy drink.

• Klíčová slova
• capillary electrophoresis, coaxial capillary arrangement, energy drinks, flow-gating interface, mineral water,
• MeSH
• elektroforéza kapilární * MeSH
• energetické nápoje analýza   MeSH
• ionty analýza   MeSH
• lithium analýza   MeSH
• minerální vody analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ionty MeSH
• lithium MeSH
• minerální vody MeSH

Pancreatic α-amylase plays an important role in dietary starch hydrolysis in the small intestine and participates in enhanced glucose concentration after meals. It seems to be a problem for diabetic patients, who suffer from longer postprandial hyperglycemia after meal consumption than healthy people. There are commercially available drugs that inhibit α-amylase and thus reduce the postprandial hyperglycemia effect. However, these drugs may cause severe side effects. Conversely, some naturally occurring flavonoids were suggested to have an α-amylase-inhibiting effect without any side effects. There had been no rapid, undemanding method in terms of sample and reagent preparation that would enable screening of many potential inhibitors. Therefore, we developed an online capillary electrophoresis method to monitor α-amylase activity in the presence of an inhibitor. Each reaction constituent was introduced separately, directly into a capillary where the reagents were mixed by diffusion, which resulted in a 5-min analysis including conditioning of the capillary. We applied the method to test the inhibitory effect of flavonoid standards and their mixture and we investigated the inhibitory effect of ethanolic extract from Betula pendula bark. The developed method presents a faster and less expensive alternative to previously described offline methods. Graphical abstract Online CE screening of α-amylase inhibitors.

• Klíčová slova
• Capillary zone electrophoresis, Online enzyme assays, Starch, α-Amylase,
• MeSH
• alfa-amylasy * antagonisté a inhibitory   MeSH
• časové faktory MeSH
• elektroforéza kapilární * ekonomika   metody   MeSH
• inhibitory enzymů analýza   MeSH
• lidé MeSH
• on-line systémy MeSH
• pankreas enzymologie   MeSH
• stabilita enzymů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alfa-amylasy * MeSH
• inhibitory enzymů MeSH