[Remediation Effect of Two Iron-modified Biochars on Slightly Alkaline Arsenic and Cadmium Contaminated Soil].

As a good passivation agent for heavy metals, modified biochar has been widely used in environmental remediation. In order to explore the effects of different modification methods on arsenic (As) and cadmium (Cd) passivation in soil by biochar, this study used co-precipitation and impregnation pyrolysis to prepare iron-modified biochar. Through adsorption experiments and soil culture experiments, the properties of biochar, adsorption capacity, and the As and Cd passivation ability in soil were analyzed. The results showed that both modification methods could increase the iron (Fe) content and zero charge point of biochar, and the Fe minerals supported by Fe-modified biochar (FeBC-1) prepared by co-precipitation were mainly Fe3O4, FeO(OH), and γ-Fe2O3. The Fe-modified biochar (FeBC-2) prepared by impregnation pyrolysis mainly consisted of α-Fe2O3 and γ-Fe2O3. FeBC-1 showed strong adsorption and removal ability for As and Cd, with a removal rate of 21.40%-34.14%, which could significantly promote the conversion of non-obligate adsorbed As to residual As in soil, whereas FeBC-2 only had a good adsorption effect on As. The adsorption capacity of BC, FeBC-1, and FeBC-2 for Cd were proportional to their CEC. The adsorption and removal effect of BC on Cd was better than that of FeBC-1 and FeBC-2, which could significantly promote the conversion of soil acid-soluble Cd to stable residue Cd.

[Enantioseparation of amlodipine maleate by capillary electrophoresis using colominic acid as a chiral selector and the mechanism of chiral recognition].

AIM: Colominic acid, a novel chiral selector, was applied to enantioseparation of dihydropyridine derivative by capillary electrophoresis. A new method was developed for enantioseparation of amlodipine maleate, a novel calcium channel blocking therapeutic agent. The chiral recognition mechanism of colominic acid to amlodipine maleate was studied. METHODS: Capillary electrophoresis was performed, and the effects of separation conditions on chiral separation were examined, including concentration of chiral selector, buffer pH, capillary temperature, applied voltage and molecular mass of colominic acid. RESULTS: The optimum conditions were additive concentration of 8.0%, buffer pH at 3.00, capillary temperature at 15 degrees C, 12 kV for applied voltage and 3 x 10(4) for molecular mass of colominic acid. Under optimum conditions complete separation was achieved between the enantiomers of amlodipine maleate with resolution as high as 2.20. CONCLUSION: The cliral separation was based on the multipoint recognition between colominic acid and amlodipine maleate. It is recommended that this simple, rapid and selective method be used for enantioseparation of amlodipine maleate. As far as polysaccharides were concerned, colominic acid was first used for enantioseparation of amlodipine maleate.

Bioequivalence evaluation of two rabeprazole enteric coated formulations in healthy Chinese volunteers.

A bioequivalence study of two rabeprazole enteric-coated formulations was carried out in 20 healthy Chinese volunteers according to a single dose, two-sequence, crossover randomized design. The two formulations were administered in two treatment days, separated by a washout period of 7 days. Blood samples were collected at specified time intervals over 10 hours post-dosing. Plasma samples were separated and assayed for rabeprazole using a selective and sensitive HPLC method with UV detection. The pharmacokinetic parameters AUC(0-T), AUCmax, Cmax, tmax, t(1/2) and MRT were determined from plasma concentration-time profile of both formulations. ANOVA and two one-sided t test procedures showed no significant difference in log-transformed Cmax, AUC(0-T) AUC(0-infinity) while the 90% confidence interval (CI) of the ratio of the geometric means of their values were also used to assess bioequivalence between the two formulations. The results of this study indicated that the two rabeprazole formulations can be considered to be bioequivalent.