Sequential injection spectrophotometric determination of trace amounts of iodide by its catalytic effect on the 4,4'-methylenebis(N,N-dimethylaniline)-chloramine-T reaction.

A simple and sensitive sequential injection spectrophotometric procedure is proposed for the determination of trace amounts of iodide in pharmaceutical preparations. The method is based on the catalytic effect of iodide on the (tetra base) 4,4'-methylenebis(N,N-dimethylaniline)-chloramine-T reaction in acidic solution. The method involves a sequential aspiration of 255mul sample/standard followed by 170mul tetra base and then 128mul chloramine-T solutions into a carrier stream to be stacked inside a holding coil and flow reversed through a reaction coil towards a detector.

Sequential injection spectrophotometric determination of iron as Fe(II) in multi-vitamin preparations using 1,10-phenanthroline as complexing agent.

A sequential injection analysis (SIA) system is proposed for the determination of iron (II). Fe(II) was determined by SIA based on the reaction between 1,10-phenanthroline and iron (II), yielding an orange-red colour complex with absorption maximum at 512nm. The method involved aspiration of 187mul sample/standard zone followed by a zone of a reagent solution containing 140mul of 7.

Spectrophotometric determination of magnesium in pharmaceutical preparations by cost-effective sequential injection analysis.

A simple and rapid, inexpensive spectrophotometric method was proposed for magnesium assay in pharmaceutical preparations by sequential injection analysis (SIA). The method is based on the reaction between o-cresolphthalein complexone (CPC) and Mg(II) in alkaline media, yielding a pink colored complex with absorption maximum at 570nm. Since the formation constant between Ca-CPC and Mg-CPC is similar, initially a sample/standard solution was aspirated into the holding coil followed by a mixture of masking-buffer solutions.

On-line dilution and determination of the amount of concentrated hydrochloric acid in the final products from a hydrochloric acid production plant using a sequential injection titration system.

An on-line sequential injection titration system for the determination of the concentration of concentrated hydrochloric acid as final product from a hydrochloric acid production plant is described. The system involves on-line dilution of the concentrated hydrochloric acid solution to an acceptable range for direct measurement by merging the sample stream with a de-ionized water diluent stream, followed by mixing in a dilution coil, before aspiration into the sequential injection system. Concentrated standard solutions were treated in exactly the same way as the samples.

Sequential injection spectrophotometric determination of etilefrine hydrochloride.

A simple, fast, economical and automated sequential injection spectrophotometric method for the determination of etilefrine hydrochloride is developed. The method is based on the condensation reaction of etilefrine hydrochloride with 4-aminoantipyrine in the presence of alkaline potassium hexacyanoferrate and the absorbance of the colored product measured at 503 nm. Aspiration order, flow rate, reaction coil diameter, reaction coil length, concentration of 4-aminoantipyrine and potassium ferricyanide, as well as aspiration volume of reagents and sample has been optimized.

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid.

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid is proposed. A solution of 0.1 mol L(-1) sodium chloride is used as carrier.

New horizons in sequential injection kinetic analysis.

The need to measure several quantities rapidly in the same sample has prompted the development of automated methods of analysis that in both the continuous and discontinuous modes offer the possibility of simultaneous determinations. The application of pH gradients and differential kinetic determinations dominate the simultaneous determination of two or more closely related species in mixtures without prior separation. Various options enable use of kinetic-based measurements for the simultaneous determination of different analytes in flow systems.