计算机辅助一清片径向展开薄层色谱定性与定量方法初探

径向薄层色谱法（RTLC）是一种将样品呈圆形或环状点样,然后将展开剂从中心向外沿径向输送的薄层色谱方法。在一定的展开距离内,RTLC是一种分离快速、扩散小、不拖尾的高效分离和半制备方法。目前关于RTLC分离的报道较多,但对RTLC定性和定量的报道较少。该文采用自编程方式结合图像处理软件,实现RTLC图像数字化处理,形成RTLC数字化图谱,并对RTLC进行定性与定量方法学验证,建立了一清片RTLC定性与定量方法。辅助计算机技术,对一清片径向展开薄层色谱定性与定量方法进行初探。结果表明,该方法用于RTLC定性的可靠度较好,但用于RTLC的定量,仍有不足之处,这可能与实验环境条件等有关。通过搭载更好的分离和数据采集设备,RTLC会有适合的用武之地。计算机图像处理和自编程方法的结合给了RTLC和其他一些分析相关的技术广阔的发展前景。相信未来在计算机技术的辅助下,薄层色谱技术会迈上一个新的台阶。     

Analysis of domperidone in pharmaceutical formulations and wastewater by differential pulse voltammetry at a glassy-carbon electrode

The redox characteristics of the drug domperidone at a glassy-carbon electrode (GCE) in aqueous media were critically investigated by differential-pulse voltammetry (DPV) and cyclic voltammetry (CV). In Britton–Robinson (BR) buffer of pH 2.6–10.3, an irreversible and diffusion-controlled oxidation wave was developed. The dependence of the CV response of the developed anodic peak on the sweep rate (ν) and on depolizer concentration was typical of an electrode-coupled chemical reaction mechanism (EC) in which an irreversible first-order reaction is interposed between the charges. The values of the electron-transfer coefficient (α) involved in the rate-determining step calculated from the linear plots of E _p,a against ln (ν) in the pH range investigated were in the range 0.64 ± 0.05 confirming the irreversible nature of the oxidation peak. In BR buffer of pH 7.6–8.4, a well defined oxidation wave was developed and the plot of peak current height of the DPV against domperidone concentration at this peak potential was linear in the range 5.20 × 10⁻⁶ to 2.40 × 10⁻⁵ mol L⁻¹ with lower limits of detection (LOD) and quantitation (LOQ) of 6.1 × 10⁻⁷ and 9.1 × 10⁻⁷ mol L⁻¹, respectively. A relative standard deviation of 2.39% (n = 5) was obtained for 8.5 × 10⁻⁶ mol L⁻¹ of the drug. These DPV procedures were successfully used for analysis of domperidone in the pure form (98.2 ± 3.1%), dosage form (98.35 ± 2.9%), and in tap (97.0 ± 3.6%) and wastewater (95.0 ± 2.9%) samples. The method was validated by comparison with standard titrimetric and HPLC methods. Acceptable error of less than 3.3 % was also achieved. Figure In aqueous media at pH 7.6- 8.4, the DPV and cyclic voltammetry of the drug domperidone (I) at GCE showed an irreversible and diffusion controlled oxidation wave. The values of the electron transfer coefficient (α) involved in the rate determining step were found in the range 0.64± 0.05 confirming the irreversible nature of the peak. The analysis of the drug in pure form and in wastewater samples was successfully achieved     

离子色谱法测定复方卡托普利片中卡托普利和氢氯噻嗪的含量

建立离子色谱法测定复方卡托普利片中卡托普利和氢氯噻嗪含量的方法。在色谱柱为IonPacSCS1(4mm×250mm),保护柱为IonPacSCG1(4mm×50mm),淋洗液为甲烷磺酸(4mmol/L)+乙腈(26%),流速1.0mL/min,柱温35℃,进样量7μL,紫外检测波长215nm的条件下,测定结果表明,卡托普利和氢氯噻嗪在0.5～25μg/mL范围内线性关系良好,相关系数r分别为0.9997、0.9999,回收率分别为98.11%、94.24%。方法操作简单,灵敏度高、准确、重现性好,可用于复方卡托普利片的质量控制。     

电感耦合等离子体原子发射光谱(ICP-AES)法测定四种奶片中的钙和镁

采用HNO3-HClO4混酸体系溶解奶片,电感耦合等离子体原子发射光谱法测定试样中的钙和镁含量,结果表明非糖果型奶片中钙和镁的含量较高。通过加标回收实验,钙和镁的加标回收率为96.7%～101%,相对标准偏差均小于3%,方法准确、快捷,为研究奶片在儿童成长发育中的作用提供了相关的依据。     

Nir-chemical imaging study of acetylsalicylic acid in commercial tablets

Near Infrared Chemical Imaging (NIR-CI) is demonstrating an increasing interest in pharmaceutical research since it meets the challenging analytical needs of pharmaceutical quality and may serve as a versatile adjunct to conventional NIR spectroscopy in many fields.The direct analysis of samples by using hyperspectral imaging techniques, which provide a NIR spectrum in each pixel of the image, generates a big amount of information from one sample. Focusing the interest in pharmaceutical research, several chemometric algorithms are demonstrating their usefulness extracting the relevant information (i.e. quantitative determination of the component in one sample) in tablets with only one sample and without damaging it.In this work, a quantitative method to analyze different commercial Acetylsalicylic acid tablets is proposed by using Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) method to the hyperspectral image and without any previous calibration model. For this purpose, a large concentration range of active pharmaceutical ingredient (ASA, Acetylsalicylic acid in this work), between 82% and 12%, was covered depending on the manufacturer. MCR-ALS allowed obtaining a concentration maps for acetylsalicylic acid and therefore, consequent analysis of the ASA distribution in the tablet was developed by using the histograms of the distribution of concentration.Results certified the good distribution of ASA despite the different origins of the tablets. Moreover, the obtained values of concentration showed a very good concordance with the nominal value of ASA. As a matter of fact, the quality of the results demonstrated the useful of encompassing NIR-CI techniques with MCR-ALS and, consequently, the well development on the production of Acetylsalicylic acid tablets.     

Determination and quantification of astragalosides in Radix Astragali and its medicinal products using LC–MS

In the present study, a liquid chromatography–tandem mass spectrometry method was developed for the separation and simultaneous quantification of astragalosides I–IV in samples of Radix Astragali and a medicinal product thereof (Jinqi Jiangtang tablets). Chromatographic separation was achieved on an Agilent Eclipse XDB (ODS)‐C18 column with a mobile phase consisting of acetonitrile and 0.05% formic acid aqueous solution by use of an efficient 17‐min program. A triple quadrupole mass spectrometer was operated in positive ionization mode with multiple reaction monitoring for the detection of four astragalosides. The saponin ginsenoside Rg1 (similar structure to astralagosides) was used as an internal standard. All calibration curves showed excellent linear regressions (r² ? 0.9912) within the range of tested concentrations. The intra‐ and inter‐day variations were below 4.57% in terms of RSD. The recoveries were 94.38–103.53% with RSD of 1.39–3.58% for spiked Radix Astragali samples. The method was successfully used for the analysis of samples of Radix Astragali and Jinqi Jiangtang tablets. In conclusion, we have developed a rapid, efficient, and accurate LC–MS/MS method for the detection of astragalosides, which can be applied for quality control of Radix Astragali and related medicinal products.     

基于线性方程组数学分离模型建立光纤传感过程检测复方缬沙坦氢氯噻嗪片溶出度

基于线性方程组数学分离模型建立在线过程检测复方缬沙坦氢氯噻嗪片溶出度方法。分别扫描缬沙坦和氢氯噻嗪的紫外吸收光谱,两组分在最大吸收波长处完全重叠。根据朗伯比尔定律吸光度加和性原理,分别测定两组分在最大吸收波长处的吸光系数,建立线性方程组数学分离模型,采用光纤传感过程分析技术(FODT)检测缬沙坦氢氯噻嗪片的溶出度,并与HPLC法相比较。在规定的溶出介质中,两种成分同时实时测定,并且FODT累积溶出度与HPLC法相比较结果无显著性差异(p>0.05)。不同批次药物的溶出行为一致,说明制剂工艺稳定,均匀度好。溶出曲线显示缬沙坦溶出快于并高于氢氯噻嗪,且30 min时两组分的溶出度均大于80%符合美国药典规定。结果表明,应用线性方程组数学分离模型结合FODT法可实现复方缬沙坦氢氯噻嗪片中双组分溶出度的同时检测,并可提供双组分的溶出过程曲线和全部溶出数据,直观反映各组分在各溶出时段的快慢,为此药建立标准提供依据。与HPLC法单点数据相比优势明显,更有利于药品评价和抽验质量分析。     

基于拉曼光谱法的降糖类药物的判别方法比较

采用了四种聚类方法对降糖类药物拉曼光谱进行了快速、无损判别。采集九种降糖类药品共48个样品的拉曼光谱,经截波、基线校正、平滑、矢量归一化等预处理后,分别采用K-均值、系统聚类法、自组织图(SOM)及PCA-SOM四种不同聚类方法做聚类判别。结果表明,自组织图与K-均值、系统聚类法相比,聚类结果较好,并且SOM结合PCA后的PCA-SOM结果最优。为降糖类药品的快速判别从聚类的角度提供了一种新的方法。     

近红外光谱法分析格列齐特片

应用化学计量法处理光谱数据,用偏最小二乘法建立格列齐特片的近红外分析模型。通过光谱预处理和模型的逐步优化最终确定定量分析模型的相关系数为0.991,交叉验证均方差(RMSECV)为0.641,预测均方根误差(RMSEP)为0.980,主因子数为4。选取15个验证样品对模型进行检验,检测结果相对误差在-2.04%～3.52%之间。     

Conductimetric,Potentiometric and Visual Titrimetric Methods for Analysis of Nadolol

Abstract

Nadolol, a beta-blocking agent, has been assayed in pure form and in pharmaceutical formulation by acidimetric titrations using visual, potentiometric and conductimetric methods for detecting the end point in aqueous as well as in non-aqueous media. The method of assay involves the determination of the amount of nadolol in a given weight of sample. Six samples were run for each method and the percentages of recovery of nadolol from its tablets were calculated. For aqueous titrations, the average percentages of recovery for the visual, potentiometric and conductimetric methods are 100.6 ± 1.0, 99.3 ± 1.9 and 100.1 ± 2.0 respectively. For the non-aqueous titrations, the average percentages of recovery are 98.6 ± 0.8, 99.5 ± 0.5 and 98.4 ± 1.3 for the visual, potentiometric and conductimetric methods respectively.