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A B S T R A C TThe impact of common cations and anions on the adsorption of uranium on rice straw activated carbon has been examined. The presence of these ions in solution was found to inhibit the uptake of cadmium by chitin to different degrees. Presence of Fe ions depressed the uranium removal to 77 and 20% at 20 and 100 mg/l, respectively. Coexistence of some anions induced small positive effect on uranium adsorption percent like Cl -; 91.0%, CO 2À 3 ; 89.3%, HCO À 3 ; 88.8%, S 2 O 2À 3 ; 93.8%, and OH -; 91.6% compared to 84.2% uranium removal. Simultaneous presence of both uranium and thorium reduced uranium sorption from 100 to 35.9 mg/g. Data were good fitted by the Langmuir isotherm with correlation coefficient higher than 0.998. This means, the adsorption is monolayer chemical in nature on homogenous surface.

A derivative UV-spectrophotometric analytical procedure was developed for determination of three 4-quinolone antibacterials: norfloxacin (NFX), ciprofloxacin (CFX), and sparfloxacin (SFX). The method depends on the complexation of Cu(II) with the studied compounds in aqueous medium. A third order, measurement was applied for their quantification. A linear correlation was established between the amplitude of the peak and concentration for all the studied drugs in the range of 15–80, 35–120, and 200–700 ng/mL, with minimum detectability (S/N = 2) of 1.0, 1.3, and 5.1 ng/mL for NFX, CFX, and SFX, respectively. The method was successfully applied for accurate, sensitive, and selective determination of the studied drugs in bulk and tablets formulation with average percentage recoveries of 99.22 ± 0.55 to 100.33 ± 1.60. The results obtained were favorably compared with those of the reference method. The method was also used to determine sparfloxacin in spiked human plasma and urine. The results obtained were satisfactory, accurate, and precise.