Sobhana K. Menon

Ion Selective Electrodes in Pharmaceutical Analysis - A Review

The applications of Ion-Selective Electrodes (ICE) in pharmaceutical analysis have been described. A compilation for different types of drugs analysed by this method is given in tabular form. The review covers the literature of the last 6 years. INTRODUCTION Ion Selective Electrodes are widely used in analytical chemistry and in the fields of clinical, biochemical· and environmental analysis. Solid ISE have longer life time compared to liquid ion selective electrodes. Page Abstract Introduction Table References.. 333 333 342 352

Ion-exchange separation and spectrophotometric determination of vanadium in environmental samples

A selective and sensitive method for the extraction and spectrophotometric determination of vanadium(V) in microgram quantities is described. The molar absorptivity of the yellow vanadium(V)-caffeic acid-Aliquat 336 extract is 1.3 x 10(4) 1.mole(-1).cm(-1) at 370nm. The method is compared with the atomic-absorption spectrometric method and applied to the trace determination of vanadium in steel, alloys, a rock and environmental samples.

Extraction and micro-determination of manganese(II) with oxine and aliquat 336

A sensitive and selective method has been developed for the micro-determination of Mn(II) by the selective extraction of the yellow Mn(II)-8-hydroxyquinolinate complex with a liquid ion-exchanger, Aliquat 336, from basic medium. The molar absorptivity of the complex is 2.2 x 10(4)1.mole(-1).cm(-1) at 420 nm and the colour system obeys Beers law in the range 0.1-3.5 ppm Mn(II) in the final solution. The composition and stability of the complex are discussed. Potential interferents have been examined and the method is applied to analysis of standard steel and bronze samples.

Spectrophotometric determination of sulphathiazole

Abstract A new, rapid, simple, selective and sensitive method for the spectrophotometric determination of sulphathiazole is described. The drug forms a yellow coloured complex with Pd(II) in alkaline medium (1 M NaOH). The drug complex exhibits maximum absorbance at 410 nm, with a molar absorptivity of 1.9 × 103 1 mol−1 cm−1. Effects of molarity of NaOH, reagent concentration on the proper complex formation are discussed. The system obeys Beers law in the concentration range of 10-160 ppm of sulphathiazole.

Extraction, spectrophotometric and atomic absorption spectrophotometric determination of molybdenum with caffeic acid and application in high purity grade steel and environmental samples

Abstract A new selective and sensitive method for extraction of yellow Mo (VI)-caffeic acid complex with a liquid ion exchanger, Aliquat 336 from 4.0 pH, and spectrophotometric determination of molybdenum in trace amounts is described. the molar absorptivity of the complex is 1.1 × 105 1 mol−1 cm−1 at 340 nm and the colour system obeys Beers law in the range 0.04–0.99 ppm of Mo(VI). the molybdenum is also determined with AAS and the method is applied for its determination in steel and environmental samples.

Micro-determination and separation of manganese using a liquid ion exchanger

A sensitive and selective method for the micro-determination of manganese has been developed involving the extraction of the wine-red manganese-benzohydroxamic acid (BHA) complex with Aliquat 336 liquid ion exchanger, and the optimum conditions have been established. Kinetic and stability studies on the complex were carried out. The extracted metal can be quantitatively eluted with 0.25 M hydrochloric acid, thus rendering the method applicable for the concentration, separation and determination of manganese in samples containing very low levels of the metal.

Micro-determination and separation of molybdenum using a liquid ion exchanger

A sensitive and selective method for the micro-determination of Mo(VI) has been developed, involving selective extraction of the yellow Mo(VI)-N-phenylbenzohydroxamic acid-SCN– complex with a liquid ion exchanger, Aliquat 336, from a medium of 2–5 M hydrochloric acid. The molar absorptivity of the complex is 7.2 × 104 l mol–1 cm–1 at 350 nm and the colour system obeys Beers law in the range 0.34–10 p.p.m. of Mo(VI). The extracted metal can be quantitatively back-extracted with 0.3 M ammonia solution, thus rendering the method applicable for the concentration, determination and separation of Mo(VI) in samples containing very low levels of the metal. Molybdenum has been determined in standard steel samples and in a plant sample.

ANALYTICAL APPLICATIONS OF LIQUID ION EXCHANGERS

Various applications of liquid ion exchangers in inorganic analysis have been reviewed. A compilation of the data for the separation and determination of various elements using both liquid caion and anion exchangers is given in tabular form. The review covers the literature of the last 10 years.