以高度磺化的β－环糊精为手性选择剂的利伐斯狄明对映体毛细管电泳分离

利用高度磺化的β－环糊精为毛细管电泳手性选择剂，成功地分离了碱性药物利伐斯狄明，并且测定了其非消旋体样品的光学纯度。一般情况下碱性药物的分离是在酸性条件下进行的（pH＝2.5），目的是为了减小分析物在毛细管内壁的吸附。然而，对于利伐斯狄明，在pH 2.5时检测灵敏度较低，且不足以检测样品中低于1％的光学杂质；但实验发现提高缓冲液的pH值可以提高其检测灵敏度；而且，由于分析物在毛细管壁吸附造成的柱效降低可以通过线性聚丙烯酰胺动态涂层来抑制。本实验考察了环糊精的浓度，缓冲液的pH值和离子强度对分离度的影响，同时通过测定重现性，线性范围，最低检测限和最低检测量对方法进行了验证。最后在最佳条件下测定了非对映异构体样品的光学纯度。     

Sensitive Method for Enantioseparation of Rivastigmine with Highly Sulfated Cyclodextrin as Chiral Selector by Capillary Electrophoresis

A sensitive method for enantioseparation of a basic drug rivastigmine and determination of its optical impurityby capillary electrophoresis with highly sulfated β-cyclodextrin(HS-β-CD)as the chiral selector is described.Ingeneral,enantioseparation of basic chiral compounds is carried out in acidic condition(pH 2.5)to prevent analytesfrom adsorption on the capillary wall.However,in the case of rivastigmine,the detection sensitivity was too limitedto determine the optical impurity of S-rivastigmine lower than 1% when buffer pH was 2.5.It was found that thedetection sensitivity was improved 1.6 times just by raising the buffer pH value from 2.5 to 5.8.The poor columnefficiency due to the adsorption of the analytes on the capillary wall was resolved by using dynamical coating of thecapillary wall with the linear polyacrylamide solution.The experirnental parameters such as the concentration ofHS-β-CD,buffer pH and buffer ionic strength were optimized,respectively.The method was validated in terms ofrepeatability,linearity,limit of detection(LOD)and limit of quantitation(LOQ).Using the present method,the op-tical purity of nonracemic rivastigmine with the enantiomeric excess(ee)value of 99.14% was determined.     

乌头酸基多色荧光碳点的制备及其分析应用

以乌头酸为前驱体,组合掺杂试剂乙二胺和尿素,以水热法和微波法分别制得4种光学性质优良的荧光碳点。荧光光谱显示,所制得的碳点中3种发射蓝色荧光,1种发射黄色荧光。实验选定蓝色荧光碳点中量子产率最高的AAEDA-HT-CDs(绝对量子产率57%)和黄色荧光碳点AAUrea-MW-CDs(绝对量子产率44%)为研究对象,对其粒径分布、元素组成以及表面基团等进行了表征。进一步研究了AAEDAHT-CDs和AAUrea-MW-CDs对金属离子的响应特性和细胞毒性,并将其成功用于细胞成像。     

利用分叉微通道提高夹切进样微流控芯片电泳可靠性的探索

微流控芯片电泳在众多领域都有广阔的应用前景,但该技术的实际应用仍不多见,成功的微流控芯片电泳分析通常需要精确调控各储液池的液面高度、电极的位置等细节,对操作者的技术要求高。该研究在传统电泳芯片的进样通道和分离通道末端引入分叉结构,增加额外的储液池,利用液面差实现进样通道末端和分离通道末端溶液的持续更新,并以有机磷除草剂为模型分析物考察了设计的适用性。结果表明,在夹切进样条件下,利用该芯片可有效缩短连续多次进样分析时的进样时间,避免基线异常抬升,显著提高了分析结果的重现性。在选定的条件下,连续测定120次未发现分离性能的变化,峰高的相对标准偏差(RSD)可达0.56%。通过调整进样时间还可避免样品基体进入分离通道,简化分离谱图。