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 on-line SPE-HPLC method using fused-core columns for on-line solid phase extraction and large volume sample injection for increasing the sensitivity of detection was developed for the determination of insecticides fenoxycarb and cis-, trans-permethrin in surface waters. The separation was carried out on fused-core column Phenyl-Hexyl (100×4.6 mm), particle size 2.7 µm with mobile phase acetonitrile:water in gradient mode at flow rate 1.0 mL min(-1), column temperature 45°C. Large volume sample injection (1500 µL) to the extraction dimension using short precolumn Ascentis Express RP C-18 (5×4.6 mm); fused-core particle size 2.7 µm allowed effective sample preconcentration and efficient ballast sample matrix removal. The washing mobile phase consisting of a mixture of acetonitrile:water; 30:70, (v/v) was pumped at flow rate of 0.5 mL min(-1) through the extraction precolumn to the waste. Time of the valve switch for transferring the preconcentrated sample zone from the extraction to the separation column was set at 3rd min. Elution of preconcentrated insecticides from the extraction precolumn and separation on the analytical column was performed in gradient mode. Linear gradient elution started from 40% of acetonitrile at time of valve switch from SPE column (3rd min) to 95% of acetonitrile at 7th min. Synthetic dye sudan I was chosen as an internal standard. UV detection at wavelength 225 nm was used and the method reached the limits of detection (LOD) at ng mL(-1) levels for both insecticides. The method showing on-line sample pretreatment and preconcentration with highly sensitive determination of insecticides was applied for monitoring of fenoxycarb and both permethrin isomers in different surface water samples in Czech Republic. The time of whole analysis including on-line extraction, interferences removal, chromatography separation and system equilibration was less than 8 min.

• Klíčová slova
• Chromatography, Fenoxycarb, Fused-core columns, On-line SPE, Permethrin, Surface water,
• MeSH
• chemické látky znečišťující vodu analýza   MeSH
• extrakce na pevné fázi MeSH
• fenylkarbamáty analýza   MeSH
• insekticidy analýza   MeSH
• jezera analýza   MeSH
• monitorování životního prostředí MeSH
• on-line systémy MeSH
• permethrin analýza   MeSH
• řeky chemie   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• fenoxycarb MeSH Prohlížeč
• fenylkarbamáty MeSH
• insekticidy MeSH
• permethrin MeSH

A new on-line preconcentration technique was developed that makes possible to determine nanomolar concentrations of weak acidic analytes in CE. The method consists of long-running electrokinetic sample injection and stacking (electrokinetic immobilization) of the analytes at a boundary of two electrolytes with different pH values (pH 9.5 and 2.5) and consequent mobilization of the stacked uncharged analytes in a micellar system (containing SDS micelles). Several factors including buffer concentration, pH, applied voltage, time of preconcentration, and SDS concentration were tested to optimize the analysis method. An about 4600-fold increase of the sample concentration (in comparison with the standard CZE) can be achieved during the preconcentration step. Two preservatives applied in food industry -- benzoic acid and sorbic acid were used as model samples. The applicability of the proposed method in food analysis was demonstrated by determination of nanomolar concentrations of benzoic acid in sunflower oil. An extended version of the computer program Simul was used for modeling both the preconcentration and mobilization processes taking place in the capillary.

• MeSH
• analýza potravin metody   MeSH
• dodecylsíran sodný chemie   MeSH
• elektroforéza kapilární přístrojové vybavení   metody   MeSH
• elektrolyty analýza   MeSH
• koncentrace vodíkových iontů MeSH
• kyselina benzoová analýza   MeSH
• kyselina sorbová analýza   MeSH
• počítačová simulace MeSH
• pufry MeSH
• reprodukovatelnost výsledků MeSH
• senzitivita a specificita MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dodecylsíran sodný MeSH
• elektrolyty MeSH
• kyselina benzoová MeSH
• kyselina sorbová MeSH
• pufry MeSH

This work presents the development of a fully automated flow-batch analysis (FBA) system as a new approach for on-line preconcentration, photodegradation and fluorescence detection in a lab-constructed mixing chamber that was designed to perform these processes without sample dispersion. The system positions the mixing chamber into the detection system and varies the instrumental parameters according to the required photodegradation conditions. The developed FBA system is simple and easily coupled with any sample pretreatment without altering the configuration. This FBA system was implemented to photodegrade and determine the fluorescence of the degradation products of metsulfuron methyl (MSM), a naturally non-fluorescent herbicide of the sulfonylurea׳s family. An on-line solid phase extraction (SPE) and clean up procedure using a C18 minicolumn was coupled to the photodegradation-detection mixing chamber (PDMC) that was located in the spectrofluorometer. An enrichment factor of 27 was achieved. Photodegradation conditions have been optimized by considering the influence of the elution solvent on both the formation of the photoproduct and on the fluorescence signal. Under optimal conditions, the calibration for the MSM determination was linear over the range of 1.00-7.20 µg L(-1). The limit of detection (LOD) was 0.28 µg L(-1); the relative standard deviation was 2.0% and the sample throughput for the entire process was 3h(-1). The proposed method was applied to real water samples from the Bahía Blanca׳s agricultural region (Bahía Blanca, Buenos Aires, Argentina). This method obtained satisfactory recoveries with a range of 94.7-109.8%.

• Klíčová slova
• Flow-batch analysis, Fluorescence, Metsulfuron methyl, On-line solid phase extraction, Photoinduced degradation,
• MeSH
• arylsulfonany analýza   MeSH
• extrakce na pevné fázi MeSH
• fluorescenční spektrometrie MeSH
• fotochemie metody   MeSH
• fotolýza MeSH
• herbicidy analýza   MeSH
• kalibrace MeSH
• koncentrace vodíkových iontů MeSH
• látky znečišťující vodu analýza   MeSH
• limita detekce MeSH
• reprodukovatelnost výsledků MeSH
• sulfonylmočovinové sloučeniny analýza   MeSH
• světlo MeSH
• technologie zelené chemie MeSH
• voda chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• arylsulfonany MeSH
• herbicidy MeSH
• látky znečišťující vodu MeSH
• metsulfuron methyl MeSH Prohlížeč
• sulfonylmočovinové sloučeniny MeSH
• voda MeSH

A contribution to the description of electrokinetic effects on the pH boundary formed by sodium borate pH 9.5 and sodium phosphate pH 2.5 electrolytes for on-line preconcentration of weak acids is presented in this article. Simulations of electrokinetic injections together with experimental studies using contactless conductivity detection verified that the preconcentration is induced mainly by dissociation changes of analytes on the pH boundary and transient ITP state. Moreover, a study of the addition of organic solvent to the injection electrolyte was performed with impressive results. Subnanomolar LODs of hydroxybenzoic acids were achieved with 80% of methanol in the injection electrolyte which represents more than 70 000-fold preconcentration in comparison with classical CZE method.

• MeSH
• elektrická vodivost MeSH
• elektroforéza kapilární metody   MeSH
• elektrolyty izolace a purifikace   MeSH
• kapilární jevy MeSH
• koncentrace vodíkových iontů MeSH
• kyselina benzoová chemie   izolace a purifikace   MeSH
• kyseliny borité chemie   MeSH
• kyseliny fosforečné chemie   MeSH
• methanol MeSH
• on-line systémy MeSH
• organické látky chemie   MeSH
• osmolární koncentrace MeSH
• oxid křemičitý MeSH
• rozpouštědla chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• boric acid MeSH Prohlížeč
• elektrolyty MeSH
• kyselina benzoová MeSH
• kyseliny borité MeSH
• kyseliny fosforečné MeSH
• methanol MeSH
• organické látky MeSH
• oxid křemičitý MeSH
• phosphoric acid MeSH Prohlížeč
• rozpouštědla MeSH

A novel transient ITP-CZE for preconcentration and determination of seven phenolic acids (caffeic acid, cinnamic acid, p-coumaric acid, ferulic acid, protocatechuic acid, syringic acid, and vanilic acid) was developed and validated. Effects of several factors such as control of EOF, pH and buffer concentration, addition of organic solvents and CDs, and conditions for sample injection were investigated. Sample self-stacking was applied by means of induction of transient ITP, which was realized by adding sodium chloride into the sample. The CZE was realized in 200 mM borate buffer ((w)(s)pH 9.2) containing 37.5% methanol, 0.001% hexadimethrine bromide, and 15 mM 2-hydroxypropyl-β-CD. Under the optimal conditions for analysis, analytes were separated within 20 min. Linearity was tested for each compound in the concentration range of 0.1-10 μg/mL (R = 0.9906-0.9968) and the detection limits (S/N = 3) ranged from 11 ng/mL (protocatechuic acid) to 31 μg/mL (syringic acid). The validated method was applied to the ethanolic extract of Epilobium parviflorum, Onagraceae. The method of SPE was used for the precleaning of the sample.

• MeSH
• elektroforéza kapilární metody   MeSH
• Epilobium chemie   MeSH
• hydroxybenzoáty analýza   MeSH
• izotachoforéza metody   MeSH
• Onagraceae chemie   MeSH
• rostlinné extrakty analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hydroxybenzoáty MeSH
• phenolic acid MeSH Prohlížeč
• rostlinné extrakty MeSH

An on-line preconcentration capillary electrophoresis (CE) technique, which combines a large volume sample stacking with a dynamic pH junction technique, is introduced in this paper. This dynamic pH junction with co-electroosmotic migration is formed between sodium borate pH 9.5 and sodium phosphate pH 2.5 with 150 mM sodium dodecylsulfate (SDS). A full capillary based injection allows determination of weak acidic compounds at ppb concentration levels (achieved LOD for benzoic acid was 11 nmol L(-1)). The proposed preconcentration method was compared with ITP/ITP (LOD 120 nmol L(-1)), ITP/CZE (LOD 740 nmol L(-1)) and a simple CZE method (LOD 23,330 nmol L(-1)). The analytical potential of this method was assessed with juice test samples.

• MeSH
• chromatografie micelární elektrokinetická kapilární metody   MeSH
• elektroforéza kapilární metody   MeSH
• elektroforéza metody   MeSH
• koncentrace vodíkových iontů MeSH
• kyselina benzoová analýza   izolace a purifikace   MeSH
• kyselina sorbová analýza   izolace a purifikace   MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• kyselina benzoová MeSH
• kyselina sorbová MeSH

After shining as the ultimate separation - sequencing technique used for the successful completion of the Human Genome Project, in the early 2000s CE experienced lowered popularity among separation scientists. The renewed interest in recent years relates to the separation needs, especially in proteomics, metabolomics, and glycomics, where CE complements liquid chromatography techniques. This interest is further boosted by the regulators requiring additional separation techniques for characterization of newly developed pharmaceuticals. This paper gives a short overview of recent developments in the on-line interfacing of CE separation techniques with electrospray ionization/mass spectrometric analysis. Both the instrumentation and selected CE/ESI/MS applications including analyses of peptides, proteins, and glycans are discussed with the stress on research published in the past 3 years. Techniques related to the proteomic and glycomic analyses such as sample preconcentration, on-line protein digestion, and analyte derivatization prior CE/ESI/MS analysis are also included.

• MeSH
• elektroforéza kapilární metody   MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací metody   MeSH
• lidé MeSH
• peptidy analýza   chemie   MeSH
• polysacharidy analýza   chemie   MeSH
• proteiny analýza   chemie   MeSH
• proteomika metody   MeSH
• systémová integrace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• peptidy MeSH
• polysacharidy MeSH
• proteiny MeSH

A new fast and sensitive method based on on-line solid-phase extraction on a fused-core precolumn coupled to liquid chromatography with fluorescence detection has been developed for ochratoxin A (OTA) and citrinin (CIT) determination in lager beer samples. Direct injection of 100 μL filtered beer samples into an on-line SPE-HPLC system enabled fast and effective sample extraction including separation in less than 6 min. Preconcentration of OTA and CIT from beer samples was performed on an Ascentis Express RP C18 guard column (5 × 4.6 mm), particle size 2.7 μm, with a mobile phase of methanol/0.5% aqueous acetic acid pH 2.8 (30:70, v/v) at a flow rate of 2.0 mL min(-1). The flow switch from extraction column to analytical column in back-flush mode was set at 2.0 min and the separation was performed on the fused-core column Ascentis Express Phenyl-Hexyl (100 × 4.6 mm), particle size 2.7 μm, with a mobile phase acetonitrile/0.5% aqueous acetic acid pH 2.8 in a gradient elution at a flow rate of 1.0 mL min(-1) and temperature of 50 °C. Fluorescence excitation/emission detection wavelengths were set at 335/497 nm. The accuracy of the method, defined as the mean recoveries of OTA and CIT from light and dark beer samples, was in the range 98.3-102.1%. The method showed high sensitivity owing to on-line preconcentration; LOQ values were found to be 10 and 20 ng L(-1) for OTA and CIT, respectively. The found values of OTA and CIT in all tested light, dark and wheat beer samples were significantly below the maximum tolerable limits (3.0 μg kg(-1) for OTA and 2000 μg kg(-1) for CIT) set by the European Union.

• Klíčová slova
• Beer, Citrinin, Fused-core column, Mycotoxins, Ochratoxin A, On-line SPE–HPLC,
• MeSH
• automatizace * MeSH
• citrinin analýza   MeSH
• extrakce na pevné fázi metody   MeSH
• ochratoxiny analýza   MeSH
• pivo analýza   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• citrinin MeSH
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH

The techniques of the on-line combination of capillary isotachophoresis with zone electrophoresis in two coupled capillaries (ITP-CZE) and a single capillary zone electrophoresis (CZE) were used for the sensitive determination of orotic acid (OA) in human urine. The simple CZE system was successfully applied for fast and reliable analyses of urine of healthy adult volunteers (the detection limit 1.7.10(-6) M OA, the total time of analysis 6 min). However, this method failed in analyses of OA in urine of ill children due to more complex matrix of the samples. Here, the ITP preconcentration and preseparation step coupled on-line with CZE proved to serve well with an electrolyte system developed and optimized for this purpose. The maximum selectivity and resolution of OA from other sample constituents in ITP-CZE was achieved by use of an electrolyte system of very low pH 2.15 both for ITP and CZE stage. The sensitivity of detection and simplicity of OA identification were enhanced by use of an external UV scanning detector. High sensitivity of ITP-CZE combination (limit of detection 3.10(-7) M OA), low sample consumption (1 microliter), good reproducibility of migration times (inter-day RSD < 1.86%) and acceptable reproducibility of the determination of OA in urine samples (average RSD = 7.27%) make this technique suitable for routine determination of trace concentration of OA especially in urine of ill children under various pathological conditions and medication.

• MeSH
• chloridy moč   MeSH
• citráty moč   MeSH
• dítě MeSH
• dospělí MeSH
• elektroforéza kapilární metody   MeSH
• elektroforéza metody   MeSH
• elektrolyty MeSH
• fosfáty moč   MeSH
• koncentrace vodíkových iontů MeSH
• kyselina orotová moč   MeSH
• laktáty moč   MeSH
• lidé MeSH
• reprodukovatelnost výsledků MeSH
• řízení kvality MeSH
• senzitivita a specificita MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chloridy MeSH
• citráty MeSH
• elektrolyty MeSH
• fosfáty MeSH
• kyselina orotová MeSH
• laktáty MeSH