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A simple method for the study of the pharmacokinetics of salbutamol using ion chromatography with direct conductivity detection without chemical suppression is presented in this paper. Baseline separation of salbutamol from plasma components was achieved by using diluted HNO 3 (2mmoll -1 ) as mobile phase with acetonitrile (6%, v/v) as modifier. Atenolol was utilized as internal...
A rapid method for the determination of Pb, Cd, Cu, Cr, Co, Ni, Mn and Zn in honey and sugars without prior digestion or ashing of the sample was developed, using inductively coupled plasma atomic emission spectrometry (ICP-AES). The critical instrumental parameters such as sample flow rate and radio frequency incident power were thoroughly optimized. The effect of matrix type and its concentration...
The possibility of applying headspace microextraction into a single drop for the determination of amines in aqueous solutions is demonstrated. A 1μl drop of benzyl alcohol containing 2-butanone as an internal standard was suspended from the tip of a micro syringe needle over the headspace of stirred sample solutions for extraction. The drop was then injected directly into a GC. The total chromatographic...
The electrochemical detection of hexavalent chromium species was investigated. It was found that Cr(VI) can undergo chemically irreversible reduction in acidic solutions at gold, glassy carbon and boron-doped diamond electrodes. The process was found to be diffusionally controlled at all three electrodes studied. The response obtained at a gold electrode towards the reduction of chromium(VI) produced...
An approach for automated fast extraction of the fat content in bakery products based on focused microwave-assisted Soxhlet extraction (FMASE) and gravimetric determination is proposed. The main factors affecting the extraction efficiency namely; power of irradiation, number of cycles and irradiation time were optimized using experimental design methodology. The proposed method was applied to six...
Two new methods for the determination of total carbonate salts, as CaCO 3 , in soil by continuous-flow piezoelectric (PZ) detection are proposed. Both use a piezoelectric flow cell and a manifold including a dynamic gas extraction device to purge gaseous CO 2 released by the sample solution upon acidification. One of the methods involves monitoring the pressure generated by the CO...
The voltammetric behaviour of chloroquine was investigated at carbon paste and dsDNA-modified carbon paste electrodes in different buffer systems over a wide pH range using cyclic and differential pulse voltammetry. Chloroquine was oxidized in the pH range 2.0-11.0 yielding one irreversible main oxidation peak. A second peak was also observed only in the pH range 5.0-7.0. The modification of the carbon...
In this study, a flow injection analysis (FIA) system using a cartridge of immobilized isocitrate lyase (ICL) and isocitrate dehydrogenase (ICDH) was developed to monitor the concentrations of succinic acid in biotechnological processes. The ICL and ICDH immobilized on VA-Epoxy Biosynth E3-carrier had a good operational lifetime (up to 24h) and storage stability (up to 30 days). The FIA system with...
Multicriteria optimization, widely used in engineering, does not much used in the optimization of analytical signals. The aim of this paper is to show the usefulness of the desirability function to optimize instrumental responses obtained in instrumental analysis. The simultaneous optimization of a signal and of its variability is a generic question of interest to any chemical analyst. It is clear...
The simple, reliable and reproducible HPLC and extraction methods were developed for the analysis of tadalafil in pharmaceutical preparation. The column used was monolithic silica column, Chromolith Performance RP-18e (100mm × 4.6mm, i.d.). The mobile phase used was phosphate buffer (100mM, pH 3.0)-acetonitrile (80:20, v/v) at the flow rate of 5mLmin −1 with UV detection at 230nm at ambient...
A simple, rapid and sensitive procedure using nonaqueous capillary electrophoresis (NACE) to measure fluoxetine and its main metabolite norfluoxetine has been developed and validated. Optimum separation of fluoxetine and norfluoxetine, by measuring at 230nm, was obtained on a 60cm × 75μm capillary using a nonaqueous solution system of 7:3 methanol-acetonitrile containing 15mM ammonium acetate, capillary...
A selective test strip based on an ion-exchange mechanism to determine magnesium is described. This optical and reversible test strip, made on a transparent polyester sheet, has a circular polymeric film of plasticised PVC that contains all of the reagents necessary to produce a response to magnesium, namely, a cation-selective neutral ionophore, 2-amino-N,N′-diheptyl-N,N′-dimethyl-butanediamide,...
Packed in a high-pressure vessel and under calculated conditions, dry ice can be used as a source of carbon dioxide for supercritical CO 2 extraction or liquid CO 2 of organic compounds from environmental samples. Coupled with a fluid modifier such as toluene, dry ice-originated supercritical CO 2 (Sc CO 2 ) achieves quantitative extraction of many volatile organic...
Uranium (VI) (U(VI)) forms a complex with dipicolinic acid (2, 6-pyridinedicarboxylic acid).This complex can be used for a highly sensitive and selective determination of uranium by adsorptive cathodic stripping voltammetry (ACSV) using a hanging mercury drop electrode (HMDE) as working electrode. Influence of effective parameters such as pH, concentration of ligand, accumulation potential and accumulation...
Solid support assisted derivatization coupled to diffuse reflectance spectroscopy (DRS) was proposed and proved useful for the detection and quantification of aliphatic amines in water as an example. Dabsyl chloride (DBS), ninhydrin and sodium 1,2-naphtoquinone 4-sulphonate (NQS) were assayed as derivatization reagents. C 18 and SDB-XC disks and C 18 cartridges were tested for amine...
The reactions of 4-chloro-7-nitrobenzofurazan (NBD-Cl) with glyphosate (GLY) and with its main metabolite, aminomethylphosphonic acid (AMPA), have been studied. The resolution of binary mixtures of glyphosate and aminomethylphosphonic acid has been accomplished by partial least squares (PLS) multivariate calibration. The method of determination is based on the fluorescence emission of the derivatives...
An approach for automated fast extraction of the fat content in bakery products based on focused microwave-assisted Soxhlet extraction (FMASE) and gravimetric determination is proposed. The main factors affecting the extraction efficiency-namely, power of irradiation, number of cycles and irradiation time-were optimized using experimental design methodology. The proposed method was applied to six...
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