The use of fluorescence in determining formation constants of complexes : Part II. Complexes which fluoresce

Four different methods for the calculation of the formation constants of fluorescing complexes are discussed. The methods were used to determine constants for the complexes of aluminum(III), gallium(III) and indium(III) with 8-quinolinol-5-sulfonate anion.     

Recovery of palladium using chemically modified cedar wood powder

Japanese cedar wood powder (CWP) was chemically modified to a tertiary-amine-type adsorbent and studied for the selective recovery of Pd(II) from various industrial waters. Batch adsorption tests performed from 0.1 M to 5 M HCl and HNO₃ systems reveal stable performance with better results in HNO₃ medium. The maximum loading capacity for Pd(II) was studied in HCl as well as in HNO₃. A continuous-flow experiment taking a real industrial solution revealed the feasibility of using modified CWP for the selective uptake and preconcentration of traces of palladium contained in acidic effluents. In addition, stable adsorption performance even on long exposure to γ-irradiation and selective recovery of palladium from simulated high-level liquid waste (HLW) are important outcomes of the study.     

Adsorption of Cu(II) from aqueous phase by Cedar bark

The capability of Cedar bark (Cedrus atlantica Manetti) (CB) for the adsorption of Cu(II) from aqueous solutions was examined. Adsorption isotherm and kinetics of Cu(II) by CB were investigated through a number of batch adsorption experiments. The effect of experimental parameters such as initial Cu(II) concentration, adsorbent mass, initial pH and ionic strength on the removal of metal ions was examined. Equilibrium data were fitted to the Langmuir, Freundlich and Harkins–Jura isotherm models. Experimental equilibrium data were best represented by the Langmuir and Harkins–Jura isotherms. The findings revealed that the CB has the potential to be used as an adsorbent for the removal of heavy-metal ions from aqueous solutions.     

GC–MS/MS method for the quantification of α‐cedrene in rat plasma and its pharmacokinetic application

α‐Cedrene is a pharmacologically active ingredient isolated from the essential oil of cedar. A selective and sensitive GC–MS/MS method was developed for the quantification of α‐cedrene in rat plasma for the first time. α‐Cedrene was extracted from rat plasma using ethyl acetate at neutral pH. The analytes were determined in selective reaction monitoring mode using MS/MS: m/z 204.3→119.0 for α‐cedrene and m/z 146.0→111.0 for 1,4‐dichlorobenzene (internal standard). The standard curve was linear (r² ≥ 0.995) over the concentration ranges of 5–800 ng/mL. The lower limit of quantification was 5 ng/mL using 50 μL of rat plasma. The coefficient of variation and relative error for intra‐ and interassays at four quality control levels were 3.1–13.9% and ?4.0–2.6%, respectively. The stability of processing (freeze–thaw, long‐term storage at ?80°C, and short‐term storage at room temperature) and chromatography (reinjection) was shown to be of insignificant effect. The present method was applied successfully to the pharmacokinetic study of α‐cedrene after its intravenous (10 mg/kg) and oral (25 mg/kg) administration in male Sprague‐Dawley rats.