title: Ion chromatographic determination of trace level phosphorus in purified quartz.
abstract: Trace levels of phosphorus in purified quartz are determined by ion chromatography. In situ reagent purification, matrix digestion and oxidation of phosphorus to orthophosphate ion are carried out simultaneously in a vapour phase digestion (VPD) assembly using a mixture of HF, HNO3 and H2O2. A drastic reduction (475 times) in phosphate blank from reagents (HF/H2O2) was achieved in the VPD through in situ purification of the reagent. The residues remaining after volatilisation (solvent/matrix), mostly consisting of insoluble phosphate/fluoride salts of divalent and trivalent cations, were solubilised by ion-exchange dissolution. Phosphate was analysed on the IonPac AS17 column with suppressed conductivity detection. The results of the ion chromatography (IC) method were compared with a spectrophotometric method. Accuracy was evaluated by analysing a certified reference material (silicon, NIST 57a). The method detection limit was 0.05 microg g(-1).
authors.affiliation: National Centre for Compositional Characterization of Materials, Bhabha Atomic Research Centre, ECIL (P.O.), Hyderabad City, Andhra Pradesh 500062, India.
authors.forename: K
authors.initials: K
authors.lastname: Dash
authors.forename: S
authors.initials: S
authors.lastname: Thangavel
authors.forename: S V
authors.initials: SV
authors.lastname: Rao
authors.forename: K
authors.initials: K
authors.lastname: Chandrasekaran
authors.forename: S C
authors.initials: SC
authors.lastname: Chaurasia
authors.forename: J
authors.initials: J
authors.lastname: Arunachalam
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D007202:Indicators and Reagents; D010758:Phosphorus / Q000032:analysis*; D011791:Quartz / Q000737:chemistry*; D012015:Reference Standards
chemical_list: D007202:Indicators and Reagents; D011791:Quartz; D010758:Phosphorus