0000000000024780

AUTHOR

C. Gómez Benito

Determination of promethazine hydrochloride with bromophenol blue by a turbidimetric method and flow injection analysis

Abstract A flow injection analysis procedure for the turbidimetric determination of promethazine is proposed. The sample solution is injected directly into the carrier reagent stream, which is composed of 1.16 × 10 −3 M bromophenol blue at pH 1.20. The calibration graph is linear over the range 25–197 ppm of promethazine. The influence of some foreign substances was also investigated. The method is applied to promethazine determination in a pharmaceutical formulation.

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Spectrophotometric and Fluorimetric Determination of 9-Amino Acridine by Flow Injection Analysis

Abstract The spectrophotometric and fluorimetric determination of 9-amino acridine is carried out by means of the FIA procedures and on the basis of its own color or fluorescence. The methanol used as a carrier stream resulted in a significative increase in sensitivity and sample throughput. The method is applied to the drug determination in pharmaceutical formulations.

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On-line photoreaction and fluorimetric determination of diazepam.

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Flow-injection spectrofluorimetric determination of paracetamol

Abstract A flow-injection spectrofluorimetric determination of paracetamol is reported, based on the oxidation of the analyte with potassium hexacyanoferrate(III) immobilized on an anion-exchange resin, the fluorescence being enhanced with N,N′-dimethylformamide. Concentrations of paracetamol in the range 0.04–17.60 mg l−1 are determined with a relative standard deviation of 1.5%. The injection rate is 25 samples h−1. The influence of foreign species and the determination of paracetamol in several pharamaceutical formulations are also reported.

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Photochemical Derivatization and Fluorimetric Determination of Promethazine in a FIA Assembly

Abstract The flow injection fluorimetric determination of promethazine is carried out by on-line photoderivatization. The PTFE tubing is helically coiled around the lamp. An analytical procedure is proposed by using aqueous solution as carrier stream: the calibration graph is linear over the range 0.05 - 20 ppm. The influence of foreign compounds is studied and the method is applied to promethazine determination in pharmaceutical formulations.

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Continuous-flow spectrophotometric determination of sulfadiazine by diazotisation with in situ preparation of nitrite

Abstract Nitrite is prepared in situ for the determination of sulfadiazine. The method is based on solid-phase reduction of copperized cadmium of nitrate; the nitrite reagent merges with the sample stream in hydrochloric acid medium and the resulting mixture is injected into the water carrier, pure distilled water, and then merges with the N-(1-naphthyl)ethylendiamine reagent and is measured spectrophotometrically at 542.0 nm. The calibration graph is linear over the range 0.5–50 μg ml−1 sulfadiazine, mid-range R.S.D. = 0.3% (n = 5) and sample throughput 72 h−1. The procedure is applied to sulfadiazine determination in a pharmaceutical formulation and to in vitro dissolution studies of two …

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Spectrofluorimetric determination of emetine by flow injection using barium peroxide and UV derivatization

Abstract The flow-injection spectrofluorimetric determination of emetine was carried out by photoderivatization in the presence of barium peroxide, in a flow-injection assembly in which the PTFE tubing in the injection valve is helically coiled around the lamp. The sample solution merges with a barium peroxidephosphoric acid solution and then the resulting mixture is irradiated; pure distilled water is used as a carrier stream. The calibration graph is linear over the range 0.05–50 μ g ml −1 of emetine dihydrochloride. The influence of foreign compounds was studied and the method was applied to the determination of emetine in injection and human urine samples.

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FIA-Chemiluminescence Determination of Acridine Yellow

Abstract The direct determination of yellow acridine is performed by a FIA assembly on the basis of the oxidation of the acridine. The acridine solution is injected into a pure water stream. This solution merges with the oxidant solution (KMnO4 in sulfuric acid medium) and the resulting chemiluminescence allows the method to be applied over the range 0.01–100 mg L−1 of acridine with a correlation coefficient of 0.9997. The relative standard deviation (%) is 1.6 and the sample throughput 60 h−1. The influence of foreign substances is also tested. The new method is applied to the determination of yellow acridine in waste waters.

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FIA-fluorimetric determination of thiamine.

A flow injection-fluorimetric determination of thiamine is reported. The procedure is based on the oxidation of the analyte with potassium hexacyanoferrate(III) immobilized on an anionic exchange resin; the fluorescence is monitored in aqueous basic solution. Concentrations of the vitamin of 0.1-4 ppm have been determined; the relative standard deviation was 1.8%. The injection rate was 28 samples/h. The influence of other substances and the determination of the drug in a pharmaceutical formulation are also reported.

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Photochemical derivatization and fluorimetric determination of reserpine in a flow-injection assembly

Abstract The fluorimetric flow-injection determination of reserpine was achieved with the drug being derivatized on-line by photoreaction. PTFE tubing was helically coiled around a germicide lamp located between the injection valve and detector. Two analytical procedures are proposed using either dilute acetic acid or pure methanol as the carrier stream. The influence of foreign compounds was studied and the method was applied to the determination of reserpine in pharmaceutical formulations.

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