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A sequential injection analysis (SIA) assembly for the atomic absorption determination of Fe(III) in natural waters is proposed. Iron is preconcentrated on a microcolumn packed with a chelating resin (Chelex 100) that is inserted in the manifold. The sample is passed through the column and the iron retained by the resin is subsequently eluted with 2 M HNO 3 . The proposed SIA system affords...
Sequential injection analysis (SIA) technique has been applied to anodic stripping voltammetry (ASV). The sample and reagent volumes can easily be controlled by SIA. The technique also allows plating of the mercury film on-line and therefore substantially reduces generation of mercury containing waste. Repeated sample passage through the detector was used during the deposition step to enhance the...
For the first time, the robust sequential injection (SI) technique has been employed for full kinetic investigation of the oxidation reaction of vitamin C. Iron(III) in sulphuric acid media was used as an oxidant and 1,10-phenanthroline as an indicator and the resulting solution of tris 1,10-phenanthroline-iron(II) complex was monitored spectrophotometrically at 510 nm. The reaction orders with respect...
A sequential injection system, based on the reaction of Cu(II) with diethyldithiocarbamate (DDTC), was developed for the determination of Cu(II) in plant food and water samples. The extraction procedure, generally used to extract the Cu(II)-DDTC complex for subsequent analysis was eliminated in this procedure. The complex was detected spectrophotometrically in aqueous solutions at 460 nm. The physical...
A sequential injection spectrophotmetric method for the assay of bromazepam anxiolytic drug has been reported. The method is based on the complexation reaction of bromazepam with iron(II) in hydrochloric acid media and spectrophotometrically measuring the product at λ max =585 nm. A comprehensive chemometrical optimization treatment was successfully utilized for determining the proper optimum...
A simultaneous detection sequential injection analysis (SIA) system is proposed for the determination of S and R captopril using a potentiometric, enantioselective membrane electrode based on maltodextrin (DE=14-17) for the assay of S-captopril and an amperometric biosensor for the assay of R-captopril. The proposed SIA system can be utilized reliably for the on-line simultaneous detection of the...
Local anaesthetics procaine hydrochloride (I), benzocaine (II), and tetracaine hydrochloride (III) were determined by the technique of sequential injection analysis (SIA) with chemiluminescence (CL) detection. The CL was emitted during the oxidation of the analytes by permanganate in aqueous sulphuric acid in the presence of various CL enhancers (4-hydroxybiphenyl, Rhodamine B, glycolaldehyde, glutaraldehyde...
A sequential injection analysis (SIA) titration method has been developed for acid-base titrations. Strong and weak acids in different concentration ranges have been titrated with a strong base. The method is based on sequential aspiration of an acidic sample zone and only one zone of the base into a carrier stream of distilled water. On their way to the detector, the sample and the reagent zones...
A fluorimetric sequential injection method for the determination of magnesium is proposed. The system is based on the complex formation between Mg(II) and 8-hydroxyquinoline-5-sulfonic acid (HQS). The reaction was carried out in the presence of ethylene glycol-bis(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) as a masking agent. Cetyltrimethylammonium chloride (HTAC) was employed as a fluorescence...
A new procedure has been developed for chromium speciation in water by sequential injection analysis and flame atomic absorption spectrometry. The method involves the online retention of Cr(VI) anionic species and Cr(III) cationic species on alumina microcolumns, prepared by packing activated alumina in polytetrafluoroethylene tubes, followed by selective elution of Cr(VI) with 2 mol l -1...
Two sequential injection systems have been developed for adsorptive stripping voltammetric measurement. One is for substances adsorbing at mercury, e.g. riboflavin. In this case, a simple arrangement with only sample aspiration is needed. Reproducibility was 3% and detection limit 0.07 μM. The measuring system was applied to determination of riboflavin in vitamin pills and to study the photodegradation...
A new sequential injection analysis (SIA) method of an electrokinetic flow analysis (EKFA) system for the determination of nitrite-nitrogen is presented in this paper. The proposed system mainly consisted of an electroosmotic pump, two solenoid valves and a spectrophotometer etc. All the pump and valves were controlled by a personal computer automatically. The determination method of nitrite-nitrogen...
A simple method for the rapid determination of paracetamol in pharmaceutical formulations is described. The method involves oxidation of paracetamol by potassium hexacyanoferrate(III) and a subsequent reaction with phenol in the presence of ammonia. The blue complex formed is measured at 630 nm. The system has a sample frequency of 27 samples per h with a detection limit of 0.2 mg l -1 ...
A dialyser unit, equipped with a passive neutral membrane, was incorporated into the conduits of a sequential injection (SI) system for the on-line removal of suspended solids and simultaneous dilution of the analyte before reaction and detection of the analyte. The system was applied to the determination of zinc(II) in fertilisers. The fully automated system is able to analyse zinc at a sampling...
Antibacterial drug trimethoprim [2,4-diamino-5-(3,4,5-trimethoxybenzyl)-pyrimidine] (I) was determined in pharmaceutical formulations by using a lab-made PC-controlled SIA analyser linked to conventional HPLC fluorimetric detector equipped with a chemiluminescence module. The chemical principle is the oxidation of I by KMnO 4 in acid medium; the reaction is accompanied by the emission of chemiluminescence,...
A procedure for determination of concentrations of iron(III) and total iron by sequential injection analysis is described. The method is based on the strong blue-colored complexes formed between iron(III) and tiron. The absorbance of the complexes is measured spectrophotometrically at 635 nm. Oxidation of iron(II) and masking of interfering fluoride is simultaneously done by injecting one zone of...
A simple and reliable sequential injection analysis (SIA) system is described for the determination of boron as boric acid in eye lotions. This method is based on the complexation reaction between d-sorbitol and boric acid followed by the acid-base reaction with methyl orange (MO). The colour change reaction is monitored at 520 nm. The system is able to monitor boron at a frequency of 30 samples per...
An automatic method for the determination of total nitrogen in wastewater by sequential injection analysis and mineralization with UV radiation has been developed. The method is based on the mineralization of the samples with sodium persulphate in basic medium under UV radiation. Small volumes of sample and reagents are firstly aspirated into a single channel and then propelled by flow reversal to...
An amperometric immunosensor based on graphite paste (graphite powder and paraffin oil) has been constructed for the assay of azidothymidine (AZT). The graphite paste is impregnated with anti-AZT. The immunosensor can be reliably used for the assay of AZT in its pharmaceutical formulation. The potential used for AZT assay was 435 mV vs Ag/AgCl electrode. The surface of the immunosensor can be regenerated...
A sequential injection analysis (SIA) system is coupled with dynamic surface tension detection (DSTD) for the purpose of studying the interfacial properties of surface-active samples. DSTD is a novel analyzer based upon a growing drop method, utilizing a pressure sensor measurement of drop pressure. The pressure signal depends on the surface tension properties of sample solution drops that grow and...
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