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A gradient elution-based ion interaction chromatography (IIC) method was developed for the determination of trace terbium (Tb) in a gadolinium (Gd) matrix. A reverse-phase column dynamically coated with camphor sulfonic acid (CSA) and α-hydroxybutyric acid (α-HIBA) as the eluent was utilized. Through a comprehensive study, an optimized gradient profile was established, which improved the separation between Tb and Gd. The limit of detection (LOD) for Tb was 2 ng/mL, and the standard deviation was 2% (n = 3) for 0.1 µg/mL Tb in the presence of 1084 µg/mL Gd. With the developed method, trace Tb determination without prior matrix separation was possible. [ABSTRACT FROM AUTHOR]

A pyrohydrolysis method has been developed for separating percentile level boron in borated Zr-Nb alloy. The pyrohydrolytic behaviour of this alloy was studied and the optimum separation conditions required for achieving complete recovery of boron were identified. Zr-Nb alloy turnings (thickness < 0.1 mm) were subjected to pyrohydrolysis at 1,230°C for 120 min with moist oxygen carrier gas at a flow rate of 2 L/min. The pyrohydrolysis distillates were analysed by ion chromatography (5 mM NaOH and d-mannitol as eluent) for boron quantification. The method showed an external precision better than 2.5%. [ABSTRACT FROM AUTHOR]

Citric acid is one of the low molecular weight organic acids which are ubiquitous in nature. In this study the sorption of citric acid at titania (anatase)/water interface was investigated using batch adsorption experiment and attenuated total reflectance - Fourier transform infrared spectroscopy (ATR-FTIR) over wide experimental conditions of pH, surface loading and ionic strengths. The batch adsorption experiment showed typical anionic characteristics; higher sorption was observed at lower pH values and sorption decreases with increasing pH. Strong dependence of sorption on ionic strength shows formation of citrate surface species in outer-sphere binding mode. At lower pH, ATR-FTIR spectra of aqueous citrate differs from that of sorbed citrate ions indicating lowering of p Ka values of surface sorbed citrate compared to that present in solution. Detailed analysis of FTIR spectra of sorbed citrate in light of that of aqueous and Ca(II)/Eu(III) complexed citrate revealed formation of an inner sphere complex of citrate on anatase surface along with the outer sphere complex. Wavenumber difference between the asymmetric and symmetric COO - peaks ( Δυ = 159 cm -1) implies inner-sphere complex in bidentate bridging mode. These results help in explaining the sorption behaviour of Eu(III) on anatase in presence of citric acid. [ABSTRACT FROM AUTHOR]