ABSTRACT
The formation of the complex between captopril and palladium(II) chloride in Britton-Robinson buffer solution was studied. It has been established that captopril reacts with palladium(II) chloride in the pH range 2.14-9.10 to form a yellow water--soluble 2:1 complex with maximum absorbance at 380 nm. By applying different spectrophotometric methods, the conditional stability constant of the complex at the optimum pH of 4.03 and ionic strength mu = 0.5 M was found to be 108.25). The molar absorptivity was 1.875 x 10(3) l mol-1 cm-1. Beer's law was obeyed in concentrations up to 5 x 10(-4) M captopril. The detection limit was 2.17 micrograms ml-1 and the relative standard deviation varied from 1.24 to 1.68%. The proposed method was found to be suitable for the accurate and reproducible analysis of captopril in water and in tablets.
Subject(s)
Captopril/chemistry , Palladium/chemistry , Captopril/analysis , Hydrogen-Ion Concentration , Palladium/analysis , Spectrophotometry, Ultraviolet , TabletsSubject(s)
Methimazole/analysis , Methimazole/chemistry , Solutions , Spectrophotometry, Ultraviolet , Tablets , WaterSubject(s)
Penicillamine/analysis , Copper , Electrochemistry , Electrodes , Indicators and Reagents , PotentiometryABSTRACT
The colour reaction of TMB-4 and palladium(II) chloride has been investigated. The optimum reaction conditions, spectral characteristics, stability constant and composition of the yellow water-soluble complex have been established. A new spectrophotometric method is proposed for microdetermination of TMB-4.
ABSTRACT
A simple and rapid method for determination of lead in blood by differential pulse stripping voltammetry (DPS) without preliminary mineralization of the sample, is described. Lead determination was performed in native samples of blood in the electrolyte of Britton-Robinson buffer (pH 5-5.5). The proposed method is shown to be reproducible and in good agreement with the reference technique AAS used on mineralized blood samples. Our results indicate that differential pulse stripping voltammetry is a reliable, rapid and highly sensitive method for blood lead analysis.
Subject(s)
Lead/blood , Electrochemistry/methods , Humans , Hydrogen-Ion ConcentrationABSTRACT
The effect of plastics as polyurethane foams and polyvinyl chloride on the metabolism of tryptophan was investigated by determining the concentration of 5-hydroxyindoleacetic acid (5-HIAA) as its metabolic end product excreted in the urine. Investigation of persons occupationally exposed to polyurethane and polyvinyl chloride showed that these plastics inhibit the metabolism of tryptophan, causing increased excretion of its easily measurable metabolite 5-HIAA. This fact points to the possibility of practical use of this laboratory test which, together with other biological parameters, could improve methods for early detection of occupational exposure to polyurethanes and polyvinyl chloride.
