Highly Selective Procedure for Trace Analysis of Platinum(IV) in Its Allied Materials

Abstract

Egypt 4-Phenylthiosemicarbazide (HPTS) was investigated as a new collector for the flotation of platinum(IV). The metal ion forms a (1: 2) pale green complex with HPTS in the aqueous solution. An intense clear green layer was formed, after flotation, by adding oleic acid (HOL) surfactant. The composition of the float is 1: 2 (Pt : HPTS). A highly selective and sensitive spectrophotometric procedure was proposed for the determination of microamounts of Pt(IV) as its floated complex. The flotation-determination method was achieved in the pH range 3 -7. Beer's law was obeyed up to 6X 10-5 mol 1-1(11.7 ppm). The interferences from various foreign ions were avoided by adding excess HPTS. The molar absorptivities of Pt-HPTS and Pt-HPTS-HOL systems are 2X103 and 4.7X1031 moL1 cm-1 at 660 and 690 nm, respectively. The formation constants of the species formed in the presence and absence of HOL are calculated. The method was successfully applied to the determination of Pt(IV) in its allied materials. A mechanism of flotation is suggested.

A New Selective Chromogenic Reagent for the Spectrophotometric Determination of Thallium(I) and (III) and Its Separation Using Flotation and the Solid-Phase Extraction on Polyurethane Foam

“…17 A flotation technique is recommended as an effective and less-expensive separation and preconcentration tool with most of the advancing factors. [18][19][20][21][22] It involves the removal of surface inactive ions from an aqueous solution with the aid of air bubbles using three modes: adsorptive flotation, precipitation flotation or adsorbing-particle flotation. 22 A process based on solid-phase extraction (SPE) has received more acceptance due to a number of possible advantages, including the availability and easy recovery of the solid phase, the attainability of a large preconcentration factor and a facility for separation.…”

Separation via Flotation, Spectrophotometric Speciation, and Determination of Vanadium(IV) in Wastes of Power Stations

“…[9][10][11][12][13][14][15][16][17][18] Consequently, such a process enabled and facilitated the spectrophotometric determination of the analyte.…”

“…On the other hand, methods for the separation and preconcentration of metals by flotation, followed by their spectrophotometric determination, have increased in popularity in recent years. [9][10][11][12][13][14][15][16][17][18] A literature survey showed that ion-flotation followed by spectrophotometric determination of V(IV) is rarely reported. 19 Also, no attempt has been found for using 1-(2-hydroxy-4-methoxybenzophenone)-4-phenylthiosemicarbazone (HMBPT) in this concern.…”

Spectrophotometric Determination of Traces of Platinum with 5-Chloro-2-hydroxythiobenzhydrazide after Extraction into Molten Naphthalene

“…6 The use of thiohydrazides such as o-hydroxythiobenzhydrazide, 7 thiobenzhydrazide, 8 α-naphthalenethiocarboxhydrazide, 2-pyrrolthiocarboxhydrazide, furanthiocarboxhydrazide, thiophenethiocarboxhydrazide, 9 dibenzylidenethiocarbohydrazide, 10 and 2-furancarbothioic acid hydrazide 11 in the spectrophotometric determination of rhenium and platinum group metals has been described in a number of papers. Other reagents such as dithizone, 12 anisaldehyde-4-phenyl-3-thiosemicarbazone, 13 dithizone-polyurathane, 14 4-phenylthiosemicarbazide, 15 3-(2′-thiazolylazo)-2,6-diaminopyridine, 16 N-(m-methylphenyl)-N′-(sodium p-aminobenzenesulfonate)-thiourea, 17 piperonal thiosemicarbazone, 18 and leuco xylene cyanol FF, 19 have been reported for spectrophotometric determination of platinum after liquid-liquid extraction. The reagents phenanthrenequinone monoximes 20,21 and 1-(2-pyridylazo)-2-naphthol 22 have been used for spectrophotometric determination of platinum after solid-liquid extraction.…”

“…These methods suffer from some drawbacks, such as a longer waiting period for color development, 7,9 a need for multiple extractions for quantitative recovery of the metal, 8 presence of stannous chloride, 12,14 narrow pH range, 10,13,19 high molarity of aqueous phase, 14,16 low absorptivity, 15 low sensitivity 13,20 and low stability of the reagents, [7][8][9] as shown in Table 1. None of these methods allow the separation and separate determination of platinum and rhenium.…”