NOPR Collection:

Spectrophotometric determination of mercury (II) with 5-(2'-carboxyphenyl) azo-8-quinolinol

Fri, 01 Jul 1994 00:00:00 GMT

Title: Spectrophotometric determination of mercury (II) with 5-(2'-carboxyphenyl) azo-8-quinolinol Authors: Saran, R; Sardana, A K; Ramanaiah, G V Abstract: 5-(2-Carboxyphenyl)azo-8-quinolinol forms a reddish violet complex with mercury(II) in aqueous medium at pH 4.4-6.5. The 2:1 (ligand to metal) complex is formed instantaneously, remains stable for at least 20 h and adheres to Beer's law in the range 0.03-0.18 ug of mercury(II) per mL. The molar absorptivity and Sandell's sensitivity of the method are 6.05 x 10⁴ L mol^-1 cm^-1 and 0.003 mg cm^-2, respectively, at 555 nm. Page(s): 258-259

Beryllium(II)-13X zeolite derivatives for the purpose of environmental control

Fri, 01 Jul 1994 00:00:00 GMT

Title: Beryllium(II)-13X zeolite derivatives for the purpose of environmental control Authors: Banerjee, Sari Prasad; Dyer, A; Enarny, H; Williams, C D Abstract: Highly toxic Be(II) ions have been exchanged for Na(I) ions in l3X synthetic zeolite. The phosphatic derivative of Be(II)-13X exhibits distinct characteristics of AlPO₄. The exchanged, ammoniated and phosphatic derivatives have been investigated by their thermal behaviour, FT-IR and X-ray diffraction. These studies confirm the utility of the zeolite in effectively removing Be (II) alongside pollution causing ammonia and P0₄(III) species. Page(s): 254-257

An equation for estimating coal conversions using super critical solventst

Fri, 01 Jul 1994 00:00:00 GMT

Title: An equation for estimating coal conversions using super critical solventst Authors: Kumari, B Krishna; Sivaji, K; Venugopal, D Abstract: Coal conversions (Y) achieved by means of solvents used under super critical conditions have been correlated to the extraction conditions, solvent properties and coal characteristics. Page(s): 251-253

Preconcentration by coflotation for the polarographic determination of traces of heavy metals in water

Fri, 01 Jul 1994 00:00:00 GMT

Title: Preconcentration by coflotation for the polarographic determination of traces of heavy metals in water Authors: Basu, Bharathibai J; Padma, D K; Rajagopalan, S R Abstract: Preconcentration by coflotation is employed to improve the detection limits for the determination of parts per billion levels of heavy metal ions such as copper(II), lead(II), cadmium(II), zinc(II), nickel(II) and cobalt(II) in natural and sea water by differential pulse polarography (OPP). Trace amounts of these ions in water are coprecipitated on colloidal aluminium hydroxide and the precipitate is floated with the aid of sodium oleate and a stream of nitrogen bubbles. Experimental conditions are optimized to obtain maximum recovery of these ions by coflotation. The effect of surfactant on the OPP peak currents of these ions in the supporting electrolyte used in this work is studied. Page(s): 248-250