title: Sequential extraction of platinum, cisplatin and carboplatin from environmental samples and pre-concentration/separation using vesicular coacervative extraction and determination by continuum source ETAAS.
abstract: A sequential extraction procedure is developed for the separation of trace levels of hexachloroplatinate, cisplatin and carboplatin from soil, which are then, pre-concentrated using a vesicular coacervative cloud point extraction method prior to their determination as platinum by continuum source ETAAS. Sequential extraction of carboplatin, cisplatin and hexachloroplatinate from a specific red soil is achieved by using the 20% HCl, aqua regia at room temperature and by combination of aqua regia and HF with microwave digestion, respectively. The pre-concentration of these species from the extracted solutions is based on the formation of extractable hydrophobic complexes of PtCl₆(2-) anionic species with free cationic head groups solubilizing sites of the Triton X-114 co-surfactant stabilized TOMAC (tri-octyl methyl ammonium chloride) vesicles through electrostatic attraction. This process separates the platinum from bulk aqueous solution into a small vesicular rich phase. The parameters affecting the extraction procedures are optimized. Under the optimized conditions, the achieved pre-concentration factor is 20 and detection limit is 0.5 ng g(-1) for soil and 0.02 ng mL(-1) for water samples. The spiked recoveries of hexachloroplatinate, cisplatin and carboplatin in water and soil extracts in the vesicular coacervative extraction are in the range of 96-102% at 0.5-1 ng mL(-1) with relative standard deviation of 1-3%. The accuracy of the method for platinum determination is evaluated by analyzing CCRMP PTC-1a copper-nickel sulfide concentrate and BCR 723 road dust certified reference materials and the obtained results agreed with the certified values with 95% confidence level of student t-test. The results were also compared to mixed-micelle (MM)-CPE method reported in the literature.
authors.affiliation: National Center for Compositional Characterization of Materials, Bhabha Atomic Research Centre, ECIL Post, Hyderabad 500 062, India.
authors.forename: Noorbasha N
authors.initials: NN
authors.lastname: Meeravali
authors.forename: K
authors.initials: K
authors.lastname: Madhavi
authors.forename: R
authors.initials: R
authors.lastname: Manjusha
authors.forename: Sunil Jai
authors.initials: SJ
authors.lastname: Kumar
mesh_terms: D016190:Carboplatin / Q000032:analysis* / Q000302:isolation & purification*; D005591:Chemical Fractionation / Q000379:methods*; D002945:Cisplatin / Q000032:analysis* / Q000302:isolation & purification*; D004784:Environmental Monitoring / Q000379:methods*; D006851:Hydrochloric Acid / Q000737:chemistry; D015394:Molecular Structure; D017942:Nitric Acid / Q000737:chemistry; D010984:Platinum / Q000032:analysis* / Q000302:isolation & purification*; D012987:Soil / Q000737:chemistry; D013054:Spectrophotometry, Atomic / Q000379:methods*; D013501:Surface-Active Agents; D014867:Water / Q000032:analysis
chemical_list: D012987:Soil; D013501:Surface-Active Agents; D014867:Water; D017942:Nitric Acid; D010984:Platinum; D016190:Carboplatin; D002945:Cisplatin; D006851:Hydrochloric Acid; C022102:aqua regia
keywords: Carboplatin; Cisplatin; Continuum source ETAAS; Inorganic platinum; Vesicular coacervative cloud point extraction