流动注射化学发光法测定盐酸曲普利啶

在碱性溶液中,N-氯代丁二酰亚胺可以氧化二氯荧光素产生化学发光。盐酸曲普利啶的存在可以显著地增强这一反应的化学发光信号。基于此,结合流动注射技术,优化了实验条件,建立了测定盐酸曲普利啶的流动注射化学发光新方法。该方法测定盐酸曲普利啶的线性范围1.0×10^-9—1.0×10^-7g/mL,检出限为5.0×10^-10g/mL。对浓度为7.0×10^-9g/mL盐酸曲普利啶溶液进行11次平行测定的相对标准偏差为4.1%。该方法已用于药物制剂中盐酸曲普利啶的含量测定,结果令人满意。     

盐酸川芎嗪的荧光光谱研究及应用

在 p H6— 10的水溶液中 ,盐酸川芎嗪产生稳定的荧光。最佳激发波长与发射波长分别为 2 95nm和335nm,当盐酸川芎嗪浓度为 5.0× 10 -6— 5.0× 10 -5mol/ L时 ,荧光强度与浓度有良好的线性关系。据此建立了荧光光度法直接测定盐酸川芎嗪注射液中盐酸川芎嗪含量的方法 ,该方法的相对标准偏差为3.51% ,检出下限为 1.0× 10 -6mol/ L。     

Nickel oxide nanotubes-carbon microparticles/Nafion nanocomposite for the electrooxidation and sensitive detection of metformin

The electrocatalytic oxidation of metformin was studied on a nickel oxide nanotubes-carbon microparticles/Nafion nanocomposite, using cyclic voltammetry and chronoamperometry. In the presence of metformin, the anodic peak current of the Ni(II)/Ni(III) transition increased, followed by a decrease in the corresponding cathodic currents. Based on the results, the drug was oxidized on nickel oxide nanotubes via an electrocatalytic mechanism. The catalytic rate constant, the electron transfer coefficient and the diffusion coefficient involved in the electrocatalytic oxidation of the drug were reported. A sensitive and efficient amperometric method was presented for the analysis of the drug, and the corresponding analytical parameters were reported. For metformin, a detection limit of 0.45 μmol L⁻¹ was obtained. The proposed amperometric method was also applied to the analysis of commercial tablets and the results were in good agreement with the declared values. Also, the applicability of the method to the direct assays of the drug in human serum and urine and breast milk was described.     

CPA矩阵法测定肺保三效片中六组分含量

本文采用ＣＰＡ矩阵法测定肺保三效片中六种组分的含量．计算程序采用ＢＡＳＩＣ语言编制．扑热息痛、苯妥英钠、咖啡因、茶碱、扑尔敏和盐酸麻黄碱的平均回收率和相对标准偏差分别为９６．１５％，０．７７％；９６．１５％，０．７２％；９６．４１％，０．６１％；９６．２２％，０．７１％；９６．１３％，０．７４％；９６．１６％，０．７７％．结果较满意．     

基于分子印迹聚合物的化学发光传感器测定尿样中的甲福明

合成了甲福明的分子印迹聚合物,以此聚合物为识别物质,在线分离富集甲福明,建立了一种测定甲福明的流动式化学发光但感器。N-溴代丁二酰亚胺(NBS)和荧光素与甲福明发生化学反应,产生强的化学发光。甲福明质量浓度在2×10-8~8×10-6g/mL范围内同发光强度成良好线性关系,方法的检出限为6×10-9g/mL,相对标准偏差小于5%(n=9)。选择性实验表明将分子印迹聚合物作为识别物质应用于化学发光分析中,能大大提高化学发光分析方法的选择性。该传感器可逆性强、稳定性好,可重复使用100次以上,已用于人体尿样中甲福明的测定。     

Simultaneous Determination of Metformin Hydrochloride, Cyanoguanidine and Melamine in Tablets by Mixed-Mode HILIC

A simple and specific hydrophilic interaction liquid chromatography (HILIC) procedure for the quantification of metformin hydrochloride (MFH) and its impurities in bulk pharmaceuticals and finished dosage forms has been developed. The method is based on hydrophilic interaction of the analytes with silica. The influence of the weaker solvent, acetonitrile, pH and the nature and ionic strength of the buffer was studied. Linearity range and percent recoveries for MFH were 100–400 μg mL⁻¹ and 100.62%, respectively. Good validation data were obtained for all compounds. The method separates impurities cyanoguanidine (CGD), melamine (MLN) and other degradation products with a run time of less than 13 min. Degradation studies involved thermal stress, hydrolysis at various pHs and chemical and photolytic oxidation.     

高效液相色谱法测定盐酸倍他司汀片的有关物质

采用Kromasil C18分析柱,水-乙腈(体积比为68：32)混合液为流动相,流速为1．0ml/min,检测波长为261nm,用高效液相色谱法测定盐酸倍他司汀片的有关物质。盐酸倍他司汀样品溶液中有关物质的色谱峰面积之和及2％盐酸倍他司汀线性对照溶液中主成分的色谱峰面积均与盐酸倍他司汀的浓度线性相关,相关系数分别为0．9991、0.9997。     

Determination of Metformin in Human Plasma by Liquid Chromatography-tandem Mass Spectrometric Assay

Introduction Metformin (1,1-dimethylbiguanide) (Fig. 1) is an oral anti-hyperglycemic agent used in the treatment of non-insulin-dependent diabetes mellitus (type Ⅱ). Owing to its weight-decreasing and serum lipid-normalizing effects, it is especially recommended for obese patients[1,2] Various analytical methods have been described for the measurement of metformin in biological fluids, including gas chromatography(GC)[3-5], capillary electrophoresis (CE)[6] and HPLC[7～16]with UV detection[7-12,17] HPLC-Mass spectrometry (LC/APCIMS/MS ) offers an attractive alternative to HPLC[18].     

Simultaneous analysis of metformin and cyanoguanidine by capillary zone electrophoresis and its application in a stability study

A capillary zone electrophoresis method was established for stability study of metformin (MET). MET and cyanoguanidine (CGN; a major degradation product) were well separated (with a resolution of 38.9) in 40 mM citrate buffer (pH 6.7) using a fused‐silica capillary with an effective length of 60 cm and an inner diameter of 50 μm, injection at 50 mbar for 5 s at 30°C with an applied voltage of 15 kV and diode array detection at 214 nm. Method validation showed good linearity (r² > 0.99), precision (%RSDs < 1.98%), and accuracy (%recovery between 98.3 and 100.9%). Limits of detection and quantification were <30 and 100 μg/mL, respectively. The method was robust upon alteration of pH and voltage (%RSDs < 1.99%). Stability profiles of metformin from 11 stress conditions and the degradation kinetics could be established, using the simple capillary zone electrophoresis system. A mechanism for the degradation of MET was also proposed. MET was stable in neutral hydrolysis, but degraded under alkaline hydrolysis and oxidation. Under both conditions, CGN was quantified as the degradation product. An assay of MET in raw material and tablets showed that content of the drugs in all samples met the requirements of pharmacopeias and CGN was not detected.     

曙红Y探针共振瑞利散射法测定盐酸二甲双胍

在pH=3.0的B-R缓冲介质中,盐酸二甲双胍(MFH)与曙红Y(EY)形成离子缔合物,引起共振瑞利散射光谱显著增强,其最大特征散射波长位于292nm处。MFH的浓度在0.05~2.5μg/mL范围内与散射信号的增强(△I_(RRS))呈线性关系。MFH的检出限(3σ)为0.02μg/mL。讨论了适宜的反应条件和共存物质的影响。据此,提出了测定痕量MFH的光散射新方法,并应用于实际样品中MFH的测定,结果满意。