No abstract

A rapid, simple, reliable, sensitive, and selective extractive spectrophotometric method was developed for the determination of silver(I) using 1-(2′,4′-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydro pyrimidine-2-thiol, [2′,4′-dinitro APTPT] as a chromogenic reagent. The procedure is based on the synergistic extraction of silver(I) with 2′,4′-dinitro APTPT in presence of 0.5 mol L–1 pyridine. 2′,4′-Dinitro APTPT reacts with silver(I) to form an orange–red ternary complex (λmax 440 nm) in the presence of 0.5 mol L–1 pyridine having a molar ratio 1:1:1 (M:L:Py) in the pH range 2.7–4.3. The Beer’s law is obeyed in the concentration range of 1–11 μg mL–1 silver(I). The molar absorptivities and Sandell’s sensitivities of the complex in the chloroform are 1.131 × 104 L·mol–1·cm–1 and 0.010 μg cm–2 in the presence of pyridine, while they are 4.962 × 104 L·mol–1·cm–1 and 0.021 μg cm–2 in the absence of pyridine, respectively. A reproducibility of the method was checked by finding the relative standard deviation (RSD) (n = 5), which was 0.12%. The method is free from interferences due to the large number of cations and anions and has been successfully applied for the determination of silver in synthetic mixtures, ayurvedic samples, silver nano materials, photographic washing wastes (hypo solution), and waste effluent from silver refineries. It is also used for sequential separation of silver(I), copper(II), and gold(III) from their mixture. The accuracy was assessed using atomic absorption spectrometry (AAS), which tested the validity of the method.

No abstract

Liquid-liquid extraction of Au(III) from aqueous sodium malonate medium using 2-octylaminopyridine (2-OAP) as an extractant in xylene was achieved. The current work explored the influence of several experimental parameters such as pH, weak acid concentration, extractant concentration, equilibrium time, stripping agents, and aqueous:organic volume ratio on the extraction of Au(III). The experimental results showed that the Au(III) was quantitatively extracted to about 99.5% by 0.05 M 2-OAP in 0.05 M malonate at 5.0 pH. Ammonia solution was used to strip the gold-loaded organic phase and about 99.5% of Au(III) was reversibly extracted into the aqueous phase. Gold(III) was extracted into the organic phase via formation of ion-pair complex [2-OAPH + .Au (C 3 H 2 O 4) − 2 ]. The stoichiometry of the extracted species was 1:2:1 (metal: acid: extractant) determined by slope analysis. The method affords the binary, ternary mixture separation as well as separation of Au(III) from synthetic mixtures and alloys. The method is applicable for the determination and separation of gold from ayurvedic samples and recovery of gold from e-wastes. A reproduction of the method was checked by finding relative standard deviation for n = 5, which was 0.29%, and the limit of detection was 1.08 µ g/mL.

No abstract

No abstract

A simple and selective method was developed for the determination of platinum(IV) with n-octylaniline in toluene. In present study, the use of n-octylaniline in toluene for the extraction of platinum(IV) from ascorbate media was carried out. The effect of various parameters, such as pH, equilibrium time, extractant concentration, and organic solvent on the extraction has been discussed. The back extraction of platinum(IV) has been performed. On the basis of slope analysis, the composition of the extracted species was determined as [RR′NH2+Pt(Succinate)2−](org). The interfering effects of various cations and anions were also studied, and the selectivity of the method is enhanced by using suitable masking agents. The proposed method is rapid, reproducible and successfully applied for the determination of platinum(IV) in binary and synthetic mixtures. The separation of pt(IV) from other associated metals has been studied. Comparison of the results with those obtained using an atomic absorption spectrophotometer also tested the validity of the method.