Cloud-Point Extraction for Preconcentration and Platinum Determination Using Spectrophotometry in Environmental Samples

Rapid spectrophotometric determination and extraction of platinum(IV) from pharmaceuticals assisted by 2-(2-(1-(thiophene-2-yl) ethylidene) hydrazinyl) benzoic acid (TEHBA)

It has been suggested that the chelating agent 2-(2-(1-thiophene-2-yl) ethylidene) hydrazinyl) benzoic acid (TEHBA) be utilized to extract, separate and measure platinum(IV) by UV-visible spectrophotometry at the microgram level. Following 5 min of heating the reaction mixture in a water bath, Pt(IV)-TEHBA complex formed. This complex was formed in the presence of potassium iodide solution with a molar absorption coefficient 1.9 × 103 dm3 mol-1 cm-1. At 420 nm, the substance exhibited the greatest absorption. As Beer's law described, the Pt(IV)-TEHBA complex for platinum(IV) has a beer's range of 10-50 μg cm-3. It was determined that the proportion ratio of the Pt(IV)-TEHBA complex was 1:1 after its extraction. Despite the investigation of interference from various ions, it was ascertained that the method exhibited selectivity exclusively towards platinum(IV). The trace amounts of platinum(IV) were extracted and quantified from synthetic mixtures representing alloys, binaries and ternary synthetic mixtures. The process of extracting platinum(IV) from pharmaceutical samples involves the implementation of a specific method. Moreover, the procedure exhibits a progressive segregation of palladium(II), platinum(IV) and nickel(II) while also boasting its ease of operation.

Utility of 5-(2',4'-dimethylphenylazo)-6-hydroxy-pyrimidine-2,4-dione in PVC membrane for a novel green optical chemical sensor to detect zinc ion in environmental samples

In plasticized (2-nitro-phenyloctyl ether (o-NPOE)) and polyvinyl chloride (PVC) membrane incorporating (N,N-diethyl-5-(octadecanoylimino)-5H-benzo[a] phenolxazine-9-amine (ETH 5294) and sodium tetraphenyl borate (NaTPB), an ionophore 5-(2',4'-dimethylphenylazo)-6-hydroxy-pyrimidine-2,4-dione (DMPAHPD) form an optical chemical sensor for zinc determination is ascribed. The sensor response is based on selective complexation of Zn²⁺ with DMPAHPD in the designed membrane phase, resulting in an ion exchange process between H⁺ in the membrane and Zn²⁺ in the sample solution. The influences of several experimental parameters, as membrane composition, pH, and type and concentration of the regenerating reagent, were demonstrated. The sensor has a response range of 5.0 × 10^-9 to 2.5 × 10^-5 M Zn²⁺ with detection and quantification limits of 1.6 × 10^-9 and 4.9 × 10^-9 M, respectively. The response time of 1 min at 0.1 M phosphate buffer solution of pH 5.0 with recording repeatability and sensor-to sensor reproducibility is reported. The proposed sensor signifies high selectivity for Zn²⁺ over various transition metal ions, alkali, and alkaline earth ions. The sensor membrane can be simply regenerated with 0.5 M HNO₃. The sensor has been used to assess Zn²⁺ in river, waste, tap, sea, well, and spring waters samples, serum of diabetic patients, powdered milk, hair, red meat, pharmaceutical formulations, and talc powder samples.

n-Capric acid-anchored silanized silica gel: its application to sample clean-up of Th(iv) sorbed as a dinuclear species in quantified H-bonded dimeric metal-trapping cores

nCA anchored to SSG surface generates 121 μM g⁻¹ H-bonded metal-trapping cores with 10-fold increase in surface area for selective uptake of {Th₂(OH)₂(H₂O)₂}⁶⁺.