Rat'ko Alexander A, Stefan Raluca-Ioana, van Staden Jacobus Koos F, Aboul-Enein Hassan Y
Department of Chemistry, University of Pretoria, Pretoria 0002, South Africa.
Talanta. 2004 Jun 17;63(3):515-9. doi: 10.1016/j.talanta.2003.11.036.
In order to determine the enantiopurity of l-carnitine three enantioselective, potentiometric membrane electrodes were proposed for the assay of l-carnitine. The electrodes were designed using macrocyclic glycopeptide antibiotics-vancomycin and teicoplanin. Acetonitrile was added to the teicoplanine to design a modified teicoplanine based electrode. The linear concentration ranges for the proposed enantioselective membrane electrodes were 10(-4) to 10(-2)moll(-1) for electrodes based on vancomycin and teicoplanin and 10(-5) to 10(-2)moll(-1) for electrode based on teicoplanin modified with acetonitrile. The slopes of the electrodes were 56.5mV per pl-carnitine; 54.5mV per pl-carnitine and 58.3mV per pl-carnitine for vancomycin-, teicoplanin- and teicoplanin modified with acetonitrile-based electrodes, respectively. The enantioselectivity was determined over d-carnitine. The proposed electrodes could be employed reliably for the assay of l-carnitine raw material and its pharmaceutical formulation, Carnilean((R)) capsules. The surfaces of the electrodes are stable and easily renewable by polishing on alumina paper.
为了测定左旋肉碱的对映体纯度，提出了三种对映体选择性电位膜电极用于左旋肉碱的测定。这些电极是使用大环糖肽抗生素——万古霉素和替考拉宁设计的。向替考拉宁中加入乙腈以设计一种基于修饰替考拉宁的电极。所提出的对映体选择性膜电极的线性浓度范围，基于万古霉素和替考拉宁的电极是10(-4)至10(-2)mol l(-1)，基于用乙腈修饰的替考拉宁的电极是10(-5)至10(-2)mol l(-1)。对于基于万古霉素、替考拉宁和用乙腈修饰的替考拉宁的电极，其斜率分别为每p左旋肉碱56.5mV、54.5mV和58.3mV。对映体选择性是相对于右旋肉碱测定的。所提出的电极可可靠地用于左旋肉碱原料药及其药物制剂Carnilean((R))胶囊的测定。电极表面稳定，通过在氧化铝纸上抛光可轻松再生。
