Study On The Application Of HPCE Technique In The Separation And Determination Of Cinchona Alkaloids

Objective:Cinchona alkaloids(Cinchona ledgeriana(Howard) Moens ex Trim.) belongs to quinoline derivative, mainly in cinchona bark, bark and root bark. Cinchona tree bark contains over thirty alkaloids. The most abundant is quinine which together with quinidine,cinchonine, and cinchonidine, which can constitute up to 16% by mass of the cinchona tree bark. Quinine was used to treat malaria, and has antipyretic analgesic and local anesthetic effect. Furthermore, quinine was used to enhance uterine contractions so commonly used to induction. Quinidine which extract from the bark and root bark can be used for the treatment of atrial fibrillation, atrial flutter, paroxysmal tachycardia and other illnesses. In recent years, cinchonidine, cinchonine and its derivatives as chiral phase transfer catalyst were applied to the large field of medicine. So, it is necessary to study the technique in separation and determination of cinchona alkaloids.The structure of quinine, quinidine, cinchonidine and cinchonine are very similar,only two C chiral contrary, in which quinine, quinidine and cinchonidine, cinchonine are stereoisomers. Thus, it is difficult to separate. In this paper, two categories of chiral selectors were used to separation of two diastereomeric pairs of cinchona alkaloids(quinine/quinidine and cinchonine/cinchonidine) by capillary electrophoresis.Methods:In this paper, separation and determination of cinchona alkaloids parameters(such as chiral selector of the type and concentration of the buffer, p H and separation voltage) were investigated in order to achieve the optimum conditions.Results:Conditions of novel complex formation cinchona alkaloids were 18 mmol·L-1 tris(hydroxymethyl) aminomethane, 3.0 mmol·L-1 Cu(II) and 20 mmol·L-1 hydroxypr-opyl-β-cyclodextrin at p H5.7, and an applied voltage of 20 k V, of which four cinchona alkaloids migration order were cinchonidine, quinine, cinchonine, quinidine and the resolution were 5.66, 3.94 and 9.08 respectively.This article also applied ligand exchange capillary electrophoresis separated four cinchona alkaloids successfully. Optical resolutions of a single of cinchona alkaloids and of mixed cinchona alkaloids were obtained with 4.0 mmol·L-1 L-lys, 2.0 mmol·L-1 Cu(II)and 30 mmol·L-1 NH4 AC at p H8.9, and an applied voltage of 15 k V performed, of which four cinchona alkaloids migration order were cinchonine, quinidine, cinchonidine, quinine,and the resolution were 1.49, 0.54 and 1.69 respectively. Quinidine and cinchonidine could not be accurately to area of integral directly due to the resolution was less than 1.2.Therefore, the first derivative spectra were used to integrate the area.Conclusion:Both methods have been successfully applied to separation and determination of some real samples, such as cinchona bark quinine injection, quinine tonic water and shampoo.