A proof of concept of a novel pervaporation sequential injection (PSI) analysis method for automatic non-chromatographic speciation analysis of inorganic arsenic in complex aqueous samples is presented. The method is based on hydride generation of arsine followed by its on-line pervaporation-based membrane separation and CCD spectrophotometric detection. The concentrations of arsenite (As(III)) and arsenate (As(V)) are determined sequentially in a single sample zone. The leading section of the sample zone merges with a citric acid/citrate buffer solution (pH 4.5) for the selective reduction of As(III) to arsine while the trailing section of the sample zone merges with hydrochloric acid solution to allow the reduction of both As(III) and As(V) to arsine at pH lower than 1. Virtually identical analytical sensitivity is obtained for both As(III) and As(V) at this high acidity. The flow analyzer also accommodates in-line pH detector for monitoring of the acidity throughout the sample zone prior to hydride generation. Under optimal conditions the proposed PSI method is characterized by a limit of detection, linear calibration range and repeatability for As(III) of 22 μg L(-1) (3sblank level criterion), 50-1000 μg L(-1) and 3.0% at the 500 μg L(-1) level and for As(V) of 51 μg L(-1), 100-2000 μg L(-1) and 2.6% at the 500 μg L(-1) level, respectively. The method was validated with mixed As(III)/As(V) standard aqueous solutions and successfully applied to the determination of As(III) and As(V) in river water samples with elevated content of dissolved organic carbon and suspended particulate matter with no prior sample pretreatment. Excellent relative recoveries ranging from 98% to 104% were obtained for both As(III) and As(V).

• Klíčová slova
• Hydride generation, Inorganic arsenic, Pervaporation, Sequential injection analysis, Speciation,
• MeSH
• arseničnany izolace a purifikace   MeSH
• arsenikové přípravky chemie   MeSH
• arsenitany izolace a purifikace   MeSH
• chemické látky znečišťující vodu izolace a purifikace   MeSH
• kalibrace MeSH
• koncentrace vodíkových iontů MeSH
• kyselina citronová chemie   MeSH
• limita detekce MeSH
• průtoková injekční analýza metody   MeSH
• řeky chemie   MeSH
• spektrofotometrie přístrojové vybavení   metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• arsenic acid MeSH Prohlížeč
• arseničnany MeSH
• arsenikové přípravky MeSH
• arsenitany MeSH
• arsenite MeSH Prohlížeč
• arsine MeSH Prohlížeč
• chemické látky znečišťující vodu MeSH
• kyselina citronová MeSH

A fully automated sequential injection system was tested in terms of its application in liberation testing, and capabilities and limitations were discussed for clotrimazole liberation from three semisolid formulations. An evaluation based on kinetic profiles obtained in short and longer sampling intervals and steady-state flux values were applied as traditional methods. The obtained clotrimazole liberation profile was faster in the case of Delcore and slower for Clotrimazol AL and Canesten cream commercial formulations. The steady-state flux values for the tested formulations were 52 µg cm-2 h-1 for Canesten, 35 µg cm-2 h-1 for Clotrimazol AL, and 7.2 µg cm-2 h-1 for Delcore measured in 4 min sampling intervals. A simplified approach for the evaluation of the initial rate based on the gradient between the second and third sampling points was used for the first time and was found to correspond well with the results of the conventional methods. A comparison based on the ratio of the steady-state flux and the initial rate values for Canesten and Clotrimazol AL proved the similarity of the obtained results. The proposed alternative was successfully implemented for the comparison of short-term kinetic profiles. Consequently, a faster and simpler approach for dissolution/liberation testing can be used.

• Klíčová slova
• Franz cell, clotrimazole, kinetic profile, liberation study, sequential injection analysis,
• MeSH
• antifungální látky analýza   MeSH
• kinetika MeSH
• klotrimazol analýza   MeSH
• laboratorní automatizace metody   MeSH
• pleťový krém MeSH
• příprava léků MeSH
• průtoková injekční analýza metody   MeSH
• uvolňování léčiv MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• Názvy látek
• antifungální látky MeSH
• klotrimazol MeSH

A review is presented on the state of the art of the chemiluminescence analysis of pharmaceuticals by the two most relevant automated controlled-flow methodologies--flow-injection analysis (FIA) and sequential-injection analysis (SIA). The current chemiluminometric applications of FIA and SIA in pharmaceutical analysis are discussed with special emphasis on the analytical figures of merit and sample matrix characteristics. The review involving 211 references and covering papers published between 2001 and 2006 is divided into several sections according to the fundamental types of chemiluminescence systems employed.

• MeSH
• léčivé přípravky analýza   MeSH
• luminiscenční měření metody   MeSH
• oxidace-redukce MeSH
• průtoková injekční analýza MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• léčivé přípravky MeSH

New generation of sequential injection analysis (SIA) called sequential injection chromatography (SIC) has already been consolidated as a good alternative of high performance liquid chromatography (HPLC) for fast analysis of simple samples. Benefits of flow methods are automation, miniaturization and low sample and mobile phase consumption. Implementation of short monolithic chromatographic column into SIA opens new area-on-line chromatographic separation of multi-compound sample in low-pressure flow system, with the advantage of flow programming and possibility of sample manipulation. In the presented review the potential of SIC and its comparison with HPLC for determination of pharmaceutical mixtures is discussed and outlines past and recent trends focused on separation with SIC.

• MeSH
• chromatografie přístrojové vybavení   metody   MeSH
• lékové formy MeSH
• lidé MeSH
• průtoková injekční analýza přístrojové vybavení   metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• lékové formy MeSH

Since its inception, sequential injection chromatography (SIC) has evolved through several stages. Key moments including introduction of the novel technique combining sequential injection analysis and monolithic column, the first generation of commercial SIC system employing robust pump, the utilization of columns packed with fused-core particles, the on-line hyphenation of extraction and separation steps in SIC, are now followed by the second generation of commercial SIC system employing stainless steel syringe pump and parts optimized for chromatographic separation. The key developments always mean acceleration of the evolution by opening new avenues and reduction of compromises in automated analytical methods based on the flow analysis. The updates, new features, and prospects of the novel instrument are described and discussed on perspective of the method developed for extraction and separation of selected phenolic acids (gallic, protocatechuic, caffeic, p-coumaric and ferulic). The method hyphenates miniaturized on-line solid phase extraction using strong anion exchange sorbent in commercial cartridge for HPLC (20 × 1 mm) and liquid chromatography using chromatographic column (C18 50 × 4.6 mm, 5 μm particles) packed with fused-core particles in the SIC manifold. The separation in gradient mode used acetonitrile: aqueous formic acid pH 2.0 mobile phase and spectrophotometric detection at 270, 300, and 320 nm. Injected sample volumes were 200 and 500 μL. The performance of the extraction step was characterized by the recovery 94.0-107.8%, enrichment factors about 20 or 50, and the separation by peak capacities 13-34, peak symmetries 1.17-1.64, and resolutions 0.82-3.75). While using a sample volume of 200 μL, our method was characterized by the following validation parameters: LODs of 0.0075-0.03 mg L-1, LOQs of 0.025-0.10 mg L-1, calibration ranges 0.025-2.50 mg L-1 (r > 0.999), repeatability of signal at 0.50 mg L-1of RSD ≤ 1.46% (n = 6), and overall time of analysis 7.1 min. The results including pilot analysis of white and red wines demonstrated the capability of novel SIC instrument to enable fast, selective, and sensitive analysis.

• Klíčová slova
• 2D method, Flow analysis, Liquid chromatography, Phenolic acids, Sequential injection chromatography, Solid phase extraction,
• Publikační typ
• časopisecké články MeSH

In this work, an application of an enzymatic reaction for the determination of the highly hydrophobic drug propofol in emulsion dosage form is presented. Emulsions represent a complex and therefore challenging matrix for analysis. Ethanol was used for breakage of a lipid emulsion, which enabled optical detection. A fully automated method based on Sequential Injection Analysis was developed, allowing propofol determination without the requirement of tedious sample pre-treatment. The method was based on spectrophotometric detection after the enzymatic oxidation catalysed by horseradish peroxidase and subsequent coupling with 4-aminoantipyrine leading to a coloured product with an absorbance maximum at 485 nm. This procedure was compared with a simple fluorimetric method, which was based on the direct selective fluorescence emission of propofol in ethanol at 347 nm. Both methods provide comparable validation parameters with linear working ranges of 0.005-0.100 mg mL(-1) and 0.004-0.243 mg mL(-1) for the spectrophotometric and fluorimetric methods, respectively. The detection and quantitation limits achieved with the spectrophotometric method were 0.0016 and 0.0053 mg mL(-1), respectively. The fluorimetric method provided the detection limit of 0.0013 mg mL(-1) and limit of quantitation of 0.0043 mg mL(-1). The RSD did not exceed 5% and 2% (n=10), correspondingly. A sample throughput of approx. 14 h(-1) for the spectrophotometric and 68 h(-1) for the fluorimetric detection was achieved. Both methods proved to be suitable for the determination of propofol in pharmaceutical formulation with average recovery values of 98.1 and 98.5%.

• Klíčová slova
• 4-Aminoantipyrine, Emulsions, Horseradish peroxidase, Propofol, Sequential Injection Analysis,
• MeSH
• ampyron metabolismus   MeSH
• automatizace MeSH
• fluorescence MeSH
• fluorometrie metody   MeSH
• indikátory a reagencie metabolismus   MeSH
• křenová peroxidasa metabolismus   MeSH
• propofol analýza   MeSH
• průtoková injekční analýza metody   MeSH
• spektrofotometrie ultrafialová metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ampyron MeSH
• indikátory a reagencie MeSH
• křenová peroxidasa MeSH
• propofol MeSH

This paper deals with a novel approach to separate two analytes with different chemical properties and different lipophilicity. The newly described methodology is based on the two column system that was used for isocratic separation of two analytes with very different lipophilicity-dexamethasone and cinchocaine. Simultaneous separation of model compounds cinchocaine and dexamethasone was carried under the following conditions in two-column sequential injection chromatography system (2-C SIC). A 25×4.6 mm C-18 monolithic column was used in the first dimension for retention and separation of dexamethasone with mobile phase acetonitrile:water 30:70 (v/v), flow rate 0.9 mL min(-1) and consumption of 1.7 mL. A 10×4.6 mm C-18 monolithic column with 5×4.6 mm C-18 precolumn was used in the second dimension for retention and separation of cinchocaine using mobile phase acetonitrile:water 60:40 (v/v), flow rate 0.9 mL min(-1) and consumption 1.5 mL. Whole analysis time including both mobile phase's aspirations and both column separations was performed in less than 4 min. The method was fully validated and used for determination of cinchocaine and dexamethasone in pharmaceutical otic drops. The developed 2-C SIC method was compared with HPLC method under the isocratic conditions of separation on monolithic column (25×4.6 mm C-18). Spectrophotometric detection of both compounds was performed at wavelength 240 nm. System repeatability and method precision were found in the range (0.39-3.12%) for both compounds. Linearity of determination was evaluated in the range 50-500 μg mL(-1) and coefficients of determination were found to be r(2)=0.99912 for dexamethasone and r(2)=0.99969 for cinchocaine.

• Klíčová slova
• Cinchocaine, Dexamethasone, Sequential injection analysis (SIA), Sequential injection chromatography (SIC), Two-column sequential injection chromatography (2-C SIC),
• MeSH
• anestetika lokální analýza   chemie   MeSH
• antiflogistika analýza   chemie   MeSH
• chromatografie metody   MeSH
• cinchokain analýza   chemie   MeSH
• dexamethason analýza   chemie   MeSH
• lékové roztoky MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• anestetika lokální MeSH
• antiflogistika MeSH
• cinchokain MeSH
• dexamethason MeSH
• lékové roztoky MeSH

In this contribution, the on-line coupling of solid phase extraction (SPE), based on a restricted-access material (RAM), with sequential injection technique (SIA) for the analysis of biological samples, is described. The SIA-RAM system was tested with a new potential antileucotrienic drug (VUFB-19363 (Quinlukast)) for serum analysis. The method is based on SPE with the novel internal-surface reversed-phase column packing material-alkyl-diol silica (ADS). The supports tolerate direct and repetitive injection of proteinaceous fluids (plasma, serum) and allow reversed-phase partitioning at the internal surface. A column packed with a 25 microm C18 alkyl-diol support was used for direct serum injection. Using a 6-port selection valve and the system of three mobile phases, the polar matrix compounds and metabolites are removed by sequentially aspirated mobile phases with lower content of the organic part (methanol-water (2:98) and following acetonitrile-water (20:80)) to the waste, and then, the analyte enriched on the column is eluted by a strong mobile phase (acetonitrile-methanol-water (40:20:40)) to the UV detector without transfer loss. With the fully automated SIA system, a total analysis time of less than 10 min was achieved. The only off-line sample pre-treatment step required to remove particulate matter was centrifugation. The studies showed a range of linearity (2-40 microg ml(-1)) and a high recovery (93.6-96.8%) of drug from the biological matrix with coefficients of variation (RSD) less than 5.0% (n = 6). This paper introduces a new, simple and robust analytical technique suitable for screening determination and direct analysis of drugs in biological materials.

• MeSH
• antagonisté leukotrienů krev   MeSH
• chinoliny krev   MeSH
• kontaminace léku MeSH
• lidé MeSH
• průtoková injekční analýza metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antagonisté leukotrienů MeSH
• chinoliny MeSH
• VUFB19363 MeSH Prohlížeč

Capillary isoelectric focusing hyphenated with mass spectrometry detection, following the sequential injection of the carrier ampholytes and the sample zone, is highly efficient for the characterization of proteins. The main advantage of the sequential injection protocol is that ampholytes, with pH ranges, which are not supposed to cover the isoelectric points of the sample components, can be used for separation. The method then allows online mass spectrometry detection of separated analytes either in the absence (substances that have left the pH gradient) or in the presence of low-level ampholytes (substances that are migrating within the pH gradient). The appearance of the substances within, or outside the pH gradient depends on, e.g., the composition of the ampholytes (broad or narrow pH range) or on the composition of electrolyte solutions. The experiments performed in coated capillaries (with polyvinyl alcohol or with polyacrylamide) show that the amount and the injection length of the ampholytes influence the length of the pH gradient formed in the capillary.

• Klíčová slova
• capillary isoelectric focusing, carrier ampholytes, mass spectrometry, proteins, sequential injection,
• MeSH
• amfolytové směsi MeSH
• elektroforéza kapilární * MeSH
• hmotnostní spektrometrie * MeSH
• isoelektrická fokusace * MeSH
• koncentrace vodíkových iontů MeSH
• proteiny izolace a purifikace   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amfolytové směsi MeSH
• proteiny MeSH

This report introduces a fully automated flow system for drug-dissolution studies based on the coupling of the sequential injection analysis (SIA) technique with a conventional dissolution apparatus. The methodology described was used for monitoring of dissolution profiles of prazosin hydrochloride (PRH) in pharmaceutical formulation. The very sensitive fluorimetric detection of PRH was performed at lambda(ex)=244 nm (lambda(em)>or=389 nm). Under the optimal conditions, the calibration curve was linear over the range 0.02-2.43 mg x l(-1) of PRH with R.S.D. 1.89, 1.23, and 1.80% (n=10) when determining 0.02, 1.22, and 2.43 mg x l(-1) of PRH in standard solutions, respectively. Equation of the calibration curve was calculated giving the following values: F=4.108 c-3.9 (n=6), r=0.9996. Detection limit was calculated 0.007 mg x l(-1) of PRH. The dissolution test of Deprazolin tablets was programmed for 60 min, with a continuous sampling rate of 70 h(-1) under conditions required by USP 26. Results obtained by SIA technique compared well with HPLC standard method.

• MeSH
• prazosin analýza   chemie   normy   MeSH
• průtoková injekční analýza metody   normy   MeSH
• řízení kvality MeSH
• rozpustnost účinky léků   MeSH
• spektrofotometrie ultrafialová metody   normy   MeSH
• tablety MeSH
• vysokoúčinná kapalinová chromatografie metody   normy   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• prazosin MeSH
• tablety MeSH