A rapid and sensitive extractive spectrophotometric determination of copper(II) in pharmaceutical and environmental samples using benzildithiosemicarbazone.

Benzildithiosemicarbazone (BDTSC) is proposed as a sensitive and selective analytical reagent for the extractive spectrophotometric determination of copper(II). BDTSC reacts with copper(II) in the pH range 1.0-7.0 to form a yellowish complex. Beer's law is obeyed in the concentration range 0.5-0.4 microg cm(-3). The yellowish Cu(II)-BDTSC complex in chloroform shows a maximum absorbance at 380 nm, with molar absorptivity and Sandell's sensitivity values of 1.63 x 10(4) dm3 mol(-1) cm(-1) and 0.00389 microg cm(-2), respectively. A repetition of the method is checked by finding the relative standard deviation (RSD) (n = 10), which is 0.6%. The composition of the Cu(II)-BDTSC complex is established as 1:1 by slope analysis, molar ratio and Asmus' methods. An excellent linearity with a correlation coefficient value of 0.98 is obtained for the Cu(II)-BDTSC complex. The instability constant of the complex calculated from Edmond and Birnbaum's method is 7.70 x 10(-4) and that of Asmus' method is 7.66 x 10(-4), at room temperature. The method is successfully employed for the determination copper(II) in pharmaceutical and environmental samples. The reliability of the method is assured by analyzing the standard alloys (BCS 5g, 10g, 19e, 78, 32a, 207 and 179) and by inter-comparison of experimental values, using an atomic absorption spectrometer.

A rapid and sensitive extractive spectrophotometric determination of palladium(II) in synthetic mixtures and hydrogenation catalysts using pyridoxal-4-phenyl-3-thiosemicarbazone.

A rapid and sensitive extractive spectrophotometric method has been developed for the determination of palladium(II) in synthetic mixtures and hydrogenation catalysts using pyridoxal-4-phenyl-3-thiosemicarbazone (PPT) as an analytical reagent. The reagent forms a red-color complex with the metal at pH 3.0, which is extracted into benzene. The absorbance is measured at 460 nm. The method adheres to Beer's law up to a concentration range of 0.4-6.4 microg cm(-3). The molar absorptivity and Sandell's sensitivity are 2.20 x 10(4) dm3 mol(-1) cm(-1) and 4.85 x 10(-3) microg cm(-2), respectively. The correlation coefficient of the Pd(II)-PPT complex is 0.99, which indicates an excellent linearity between two variables. The detection limit of this method is 0.05 microg cm(-3). The instability constant of the Pd(II)-PPT complex calculated from Edmond and Birnbaum's method is 2.90 x 10(-5) and that of Asmus' method is 2.80 x 10(-5) at room temperature. The concurrent repetition of the method is checked and the relative standard deviation (RSD) (n = 5) was derived as 1.84 percent. The present method was applied to the determination of palladium(II) in synthetic mixtures and hydrogenation catalysts. The results were compared by employing an atomic-absorption spectrometer.