The electrochemical behavior of the degradation product of cefdinir（CDR） was studied in a 0.05 mol/L NaOH solution by means of linear sweep voltammetry（LSV） and cyclic voltammetry（CV）. The results indicate that ...The electrochemical behavior of the degradation product of cefdinir（CDR） was studied in a 0.05 mol/L NaOH solution by means of linear sweep voltammetry（LSV） and cyclic voltammetry（CV）. The results indicate that the C=N bond in the oxime group was reduced. Moreover, a saturated adsorption amount of 1.32× 10^-10 mol/cm2 at Hg electrode was obtained. The adsorption coefficient β was 1.56× 10^5 L/mol. Gibbs standard energy of adsorption AGO at 25 ℃ was -29.63 kJ/mol and the number of electrons transferred n was 2. A method for the determination of CDR was proposed by differential pulse voltammetry（DPV）. The reduction peak currents of the CDR＇s degradation product were found to be linear in a concentration range of 4.0×10^-7--4.0×10^- 6 mol/L and that of 4.0× 10^-8-4.0× 10^-7 mol/L, respectively. The detection limit was found to be 3.0× 10^-8 mol/L under the optimized conditions. The applica- bility of this approach was illustrated by the determination of CDR in capsules. In addition, the mechanism about the degradation of CDR in 0.2 mol/L NaOH was discussed by UV spectrophotometry.展开更多
The following article has been retracted due to the investigation of complaints received against it. The Editorial Board found that there are conflicts of interests between the authors and their organization. The scie...The following article has been retracted due to the investigation of complaints received against it. The Editorial Board found that there are conflicts of interests between the authors and their organization. The scientific community takes a very strong view on this matter, and the American Journal of Analytical Chemistry treats all unethical behavior seriously. This paper published in Vol. 6 No. 3 239-254, 2015 has been removed from this site. Title: Determination of Antibiotic Drug Cefdinir in Human Plasma Using Liquid Chromatography Tandem Mass Spectroscopy Author: Mohammad A. Al Bayyari, Raed S. Abu展开更多
目的建立反相高效液相色谱法测定头孢地尼及制剂中的聚合物杂质。方法以CAPCELL PAK C_(18)MGⅡ为色谱柱(250 mm×4.6 mm,5μm),0.25%四甲基氢氧化铵溶液(p H 5.5)[每1000mL中加入0.1 mol/L乙二胺四乙酸二钠溶液0.4 mL]-甲醇-乙腈...目的建立反相高效液相色谱法测定头孢地尼及制剂中的聚合物杂质。方法以CAPCELL PAK C_(18)MGⅡ为色谱柱(250 mm×4.6 mm,5μm),0.25%四甲基氢氧化铵溶液(p H 5.5)[每1000mL中加入0.1 mol/L乙二胺四乙酸二钠溶液0.4 mL]-甲醇-乙腈为流动相系统,梯度洗脱,建立了头孢地尼聚合物类杂质的分析方法并进行了方法学验证。采用二维液质联用法对检出的聚合物类杂质进行定性分析。结果在该色谱条件下头孢地尼及已知杂质均与头孢地尼聚合物间分离良好,头孢地尼检测浓度的线性范围为0.30~30.1μg/mL(r=1.0000),方法的检测限与定量限分别为1.5 ng和4.5 ng。所建立的方法能够检出头孢地尼二聚体,头孢地尼二聚体的多个同分异构体及头孢地尼三聚体。结论本方法专属性好,灵敏度高,耐用性好,可用于头孢地尼及其制剂中聚合物杂质的控制。展开更多
基金Supported by the Natural Science Foundation of Shaanxi Province in China(No.2005B28)
文摘The electrochemical behavior of the degradation product of cefdinir（CDR） was studied in a 0.05 mol/L NaOH solution by means of linear sweep voltammetry（LSV） and cyclic voltammetry（CV）. The results indicate that the C=N bond in the oxime group was reduced. Moreover, a saturated adsorption amount of 1.32× 10^-10 mol/cm2 at Hg electrode was obtained. The adsorption coefficient β was 1.56× 10^5 L/mol. Gibbs standard energy of adsorption AGO at 25 ℃ was -29.63 kJ/mol and the number of electrons transferred n was 2. A method for the determination of CDR was proposed by differential pulse voltammetry（DPV）. The reduction peak currents of the CDR＇s degradation product were found to be linear in a concentration range of 4.0×10^-7--4.0×10^- 6 mol/L and that of 4.0× 10^-8-4.0× 10^-7 mol/L, respectively. The detection limit was found to be 3.0× 10^-8 mol/L under the optimized conditions. The applica- bility of this approach was illustrated by the determination of CDR in capsules. In addition, the mechanism about the degradation of CDR in 0.2 mol/L NaOH was discussed by UV spectrophotometry.
文摘The following article has been retracted due to the investigation of complaints received against it. The Editorial Board found that there are conflicts of interests between the authors and their organization. The scientific community takes a very strong view on this matter, and the American Journal of Analytical Chemistry treats all unethical behavior seriously. This paper published in Vol. 6 No. 3 239-254, 2015 has been removed from this site. Title: Determination of Antibiotic Drug Cefdinir in Human Plasma Using Liquid Chromatography Tandem Mass Spectroscopy Author: Mohammad A. Al Bayyari, Raed S. Abu
