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Serum is rapidly digested with a mixture of nitric and perchloric acids at a temperature of 180 ± 10°C, and hydrochloric acid is used to reduce selenium(VI) to selenium(IV). Selenium is determined by hydride generation flame atomic absorption spectrometry. The results show that this method has the advantages of being sensitive, accurate, rapid and simple. After the serum is digested and diluted,...
A flow-injection system with an immobilized enzyme reactor is proposed for the determination of l-phenylalanine. Phenylalanine dehydrogenase from Rhodoccus sp. M4 was immobilized on tresylated poly (vinyl alcohol) beads (13 μm) and packed into a stainless-steel column (5 cm 4 mm i.d.). Serum sample was deproteinized with tungstic acid and filtered through an ultrafiltration membrane. The sample...
A differential pulse voltammetric enzyme-linked immunoassay for the determination of helicobacter pylori (H. pylori) specific IgG antibody in human serum has been developed. The method is based on coupling the oxidation reaction of 3,3 ,5,5 -tetramethylbenzidine (TMB)-H 2 O 2 that is catalysed by horseradish peroxidase-IgG(HRP-IgG) conjugate with the electro-reduction of the enzymatic...
The simultaneous determination of copper and zinc in human plasma and urine by inductively coupled plasma mass spectrometry (ICP MS) is discussed. The performances of a cross-flow nebulizer and a direct-injection nebulizer (DIN) were compared. Flow-injection-DIN-ICP MS analysis of clinical samples using 1–2 μl samples was optimized. Isobaric interferences were discussed and were demonstrated to be...
The classification of normal and cancer groups with four multivariate methods according to metal contents in serum and hair samples has been discussed in the present paper. Results show that the four multivariate methods, stepwise discrimination analysis, principal components analysis, hierarchical cluster analysis, and stepwise cluster analysis can distinguish the two groups correctly. The independent...
A water-soluble porphyrin, (2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(4-sulfonatophenyl)porphyr in; H 2 obtpps 4- ) was synthesized and developed for the determination of lithium ion in aqueous solution. The octabromo groups lower the basicity of the porphyrin by their electron-withdrawing effect, and enable the porphyrin to react with the lithium ion in alkaline solution...
A flow injection enzymatic method for the spectrophotometric determination of l-phenylalanine has been developed. l-phenylalanine is deaminated in the presence of l-amino acid oxidase and the keto acid formed is made to react with borate to give a coloured enol-borate complex that can be detected at 282 nm. Catalase is added to the catalyzed reaction to prevent the keto acid being destroyed by the...
The measurement precision and accuracy that results from the use of a sample introduction peristaltic pump system for automated instrument calibration and analysis is compared to manual methods based on traditional gravimetric and volumetric dilution procedures for flame atomic absorption analyses in water and serum matrices. Whilst use of the automated system improves speed of analysis, measurement...
Second-derivative synchronous fluorescence spectrometry was used to develop a simple, rapid and sensitive spectrofluorimetric method for the determination of binary mixtures of the nonsteroidal antiinflammatory drugs flufenamic (FFA), meclofenamic (MCFA) and mefenamic (MFA) acids in serum and pharmaceutical formulations. The method is based on the intrinsic fluorescence of these compounds in chloroform...
Spectrofluorimetric methods to determine cisatracurium and mivacurium are proposed and applied to the determination of both substances in human serum and to the determination of mivacurium in pharmaceuticals. The fluorimetric methods allow the determination of 5-500 ng ml -1 of mivacurium in aqueous solutions and 5-500 ng ml -1 of cisatracurium in water-acetonitrile solutions,...
A method for the determination of salsalate at concentrations between 0.10 and 1.00 μg ml -1 by means of fluorescence spectrometry technique is proposed. Salsalate, lightly soluble in water, is totally extracted into chloroform. In this organic phase, the drug shows low fluorescence but when an alkaline medium is provided, salsalate undergoes a substantial increase of the fluorescent...
A spectrofluorimetric method to determine levofloxacin is proposed and applied to determine the substance in tablets and spiked human urine and serum. The fluorimetric method allow the determination of 20-3000 ng ml -1 of levofloxacin in aqueous solution containing acetic acid-sodium acetate buffer (pH 4) with λ exc =292 and λ em =494 nm, respectively. Micelle...
The electrochemical oxidation of cisatracurium was investigated by cyclic voltammetry and differential pulse voltammetry at a carbon paste electrode and the experimental parameters have been optimized in order to obtain the optimum analytical signal. A differential pulse voltammetric method with carbon paste electrode is described for the determination of cisatracurium with detection limit of 0.38...
A HPLC method has been developed for the direct assay of fleroxacin in serum, without previous extraction. Serum samples, after the addition of sodium dodecylsulfate (0.5%), were injected directly into an LC Hisep column. The mobile phase consisted of acetonitrile, water and triethylamine in a per cent volume ratio 18:80:2. The pH of the mobile phase was adjusted to 6.50 with the addition of phosphoric...
The quinolone antibacterial agent nalidixic acid (NAL) was studied by cyclic voltammetry (CV) and cathodic adsorptive stripping voltammetry (CASV). A sensitive method is described for the determination of NAL in its pure form, dosage forms and biological fluids. Controlled adsorptive accumulation of NAL on a hanging mercury drop electrode provides the basis for the direct stripping measurement of...
A method for the determination of salicylamide at concentrations between 25 and 350 ng ml -1 by use of matrix isopotential synchronous fluorescence spectrometry (MISF) in combination with derivative techniques is proposed. The method allows the determination of compounds in samples with unknown background fluorescence without the need for tedious pre-separation. Synchronous scans are...
A rapid and simple flow-through solid phase spectrofluorimetric system is described in this paper for the determination of the diuretic amiloride in physiological fluid (serum) and pharmaceuticals. The sensor was developed in conjunction with a monochannel flow-injection analysis system with fluorimetric transduction. Amiloride was transitorily retained on cationic exchanger gel Sephadex SP-C25 placed...
A method for determination of manganese and selenium in serum by simultaneous atomic absorption spectrometry (SIMAAS) is proposed. The samples (30 μl) were diluted (1+3) to 1.0% v/v HNO 3 +0.10% w/v Triton X-100 directly in the autosampler cups. A total of 20 μg Pd+10 μg Mg(NO 3 ) 2 was used as chemical modifier. The pyrolysis and atomization temperatures for the simultaneous...
Polyvinylalcohol was activated with 2-fluoro-1-methylpyridiniumtoluene-4-sulphonate and urease (EC.3.5.1.5) was covalently linked to the activated matrix. PVA-urease was then immobilized on the surface of a pH glass electrode with gelatine gel and it was cross-linked using glutaraldehyde. This potentiometric membrane electrode provides a linearity to urea in the 8.910 -5 to 1.110 ...
The adsorptive and electrochemical behavior of amlodipine besylate on a glassy carbon electrode were explored in Britton–Robinson buffer solution by using cyclic and square-wave voltammetry. Cyclic voltammetric studies indicated the oxidation of amlodipine besylate at the electrode surface through a single two-electron irreversible step and fundamentally controlled by adsorption. The solution conditions...
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