奥硝唑在多壁碳纳米管碳糊电极上的电化学行为及其测定

基于对奥硝唑在多壁碳纳米管碳糊电极上的电化学行为及反应机理的研究,提出了测定奥硝唑的电化学分析法,优化了测定奥硝唑的各试验参数.在pH 2.21的B-R缓冲溶液中,奥硝唑浓度在1.0×10-4～5.0×10-4mol·L-1之间与其还原峰电流呈线性关系,检出限为5.0×10-7mol·L-1.用此法测定了片剂中奥硝唑的含量,加标回收率在95%～105%之间,测定值的相对标准偏差(n=7)在5.10%～5.23%之间.试验证实,奥硝唑在电极上的还原反应为主要受扩散控制的不可逆过程.     

奥硝唑与氯醌酸的荷移反应研究

研究了奥硝唑与氯醌酸在正丙醇介质的荷移反应,建立了一种快速简便测定奥硝唑的荷移分光光度法.在室温下,荷移反应生成2∶1的荷移络合物,最大吸收波长为534nm,表观摩尔吸光系数为ε=1.08×104 L·mol-1·cm-1.奥硝唑的浓度在5.0~83mg/L范围内服从比尔定律,相关系数r=0.999 3,相对标准偏差为1.3%~2.1%,回收率为99.1%~101.7%.     

基于甲基丙烯酰胺基芘荧光载体光聚合膜的奥硝唑传感器

合成了一种端基烯键的芘衍生物荧光载体-甲基丙烯酰胺基芘(MAAP)。基于光聚合反应将该荧光载体共聚固定于玻片表面,利用奥硝唑对共价固定膜甲基丙烯酰胺基芘的熄灭作用,研制了一种测定奥硝唑的荧光传感器。传感器避免了荧光载体的泄漏,具有较好的稳定性、重现性和选择性,使用寿命长。奥硝唑测定的线性范围为1.0×10-6~1.0×10-3mol/L;检出限为4.0×10-7mol/L;将传感器用于水样中奥硝唑的直接测定,回收率在93.8%~110.5%。     

用光谱法研究奥硝唑与人血清白蛋白的相互作用

采用荧光光谱法和紫外可见吸收光谱法研究了奥硝唑与人血清白蛋白之间的相互作用;求得了二者在不同温度下的结合常数KA和结合位点数n,以及对应温度下结合反应的热力学参数,同时采用同步荧光分析技术探讨了蛋白质与药物结合时构象的变化.结果表明,在生理条件下奥硝唑对人血清白蛋白的荧光猝灭主要为静态猝灭;奥硝唑与人血清白蛋白主要靠静电作用力结合.     

甲基红共振瑞利散射法测定多肽药物奥曲肽

采用共振瑞利散射(RRS)法测定奥曲肽,建立了测定痕量奥曲肽的方法。在pH=3.78的B-R缓冲溶液中,奥曲肽与甲基红相互作用后,共振瑞利散射显著增强,在280～370nm范围内呈现高的散射强度,且以310nm处的ΔIRRS最强。在优化的测试条件下,奥曲肽浓度在0～0.54mg/L范围内与散射强度有良好的线性关系,对奥曲肽的检出限(3σ)达3.6μg/L。该方法用于合成样品中奥曲肽的测定,回收率为98.3%～100.7%;用于奥曲肽注射液中奥曲肽含量的测定,结果与HPLC法测得的结果相近。     

顶空进样GC-SIM-MS测定硝唑尼特中溶剂残留甲醇含量

利用气相色谱-选择离子监测质谱联用仪(GC-SIM-MS)测定硝唑尼特样品中溶剂残留甲醇的含量,顶空进样,温度为70℃,时间为20 min.SIM定量离子m/z 32,参考离子m/z 31,30和29.甲醇质量浓度在0.5~100μg/m L内呈良好的线性(R~2=0.999 92).方法相对标准偏差为2.49%~4.85%,样品加标回收在94.5%~102.8%之间,检测限为0.5μg/m L,符合定量分析的要求.     

高灵敏共振瑞利散射法对痕量药物奥曲肽的测定

采用共振瑞利散射法测定多肽药物奥曲肽.在pH 4.1的B-R缓冲溶液中,奥曲肽和石蕊相互作用后,共振瑞利散射显著增强,在285 ～367 nm范围内呈现高的散射强度,且以310 nm处的ΔIRRS最强.奥曲肽的质量浓度在0.007 3 ～0.45 mg/L范围内与ΔIRRS成正比,检出限(3σ)为2.2 μg/L.该法用于奥曲肽合成样品和注射液中奥曲肽含量的测定,结果满意,实现了以廉价试剂、简便方法快速测定痕量贵重药品的目的.     

双功能单体法制备磁性奥硝唑分子印迹聚合物及应用

采用悬浮聚合法,以奥硝唑(ONZ)为模板分子、甲基丙烯酸(MAA)和丙烯酰胺(AA)为双功能单体、二甲基丙烯酸乙二醇酯(EDMA)为交联剂,利用Fe_3O_4磁性纳米粒子制备了奥硝唑磁性分子印迹聚合物(MMIPs)。通过扫描电子显微镜(SEM)、红外光谱(FT-IR)、磁化强度分析(VSM)、紫外-可见吸收光谱(UV-Vis)及热重分析(TGA)等对合成的聚合物进行了表征。结果表明,双功能单体MMIPs对奥硝唑的吸附量高于相应的单功能单体MMIPs;对类似物质也有一定的吸附能力。利用等温吸附数据进行Scatchard分析,从而推断出MMIPs对于模板分子的作用存在两种不同的结合位点,最大吸附量Q_(max1)为48.96μmol/g,Q_(max2)为10.60μmol/g。结合高效液相色谱分析技术,将所制备的MMIPs应用于河水样品中硝基咪唑类抗生素的提取富集,加标回收率为85.4%~104.3%,方法简便易行、准确可靠。     

气相色谱-电子捕获检测器同时测定硝基咪唑类药物

建立了气相色谱-电子捕获检测器同时测定硝基咪唑类药物含量的方法.样品用磷酸盐调节pH约为8.8,乙酸乙酯提取,无水硫酸钠脱水.采用CBP-1毛细管柱分离,电子捕获检测器检测.甲硝唑、替硝唑、奥硝唑分别在0.2～15 μg/mL、5.3～53μg/mL、4.0～40μg/mL范围内与峰面积呈良好线性关系,相关系数r分别为0.9993、0.9996、0.9995.样品加标回收率在95.8%～101%之间,相对标准偏差在1.8%～3.4%之间.本法简便、快速,可用于片剂和注射液中硝基咪唑类药物含量的测定.     

高效液相色谱法定量分析奥曲肽

建立奥曲肽的高效液相色谱定量分析方法。色谱柱为Eclipse plus C18柱(4.6 mm×250 mm,5 μm),流动相为乙腈-0.25%高氯酸水溶液(体积比为30∶70),流量为1.0 mL/min,检测波长为210 nm,柱温为25℃。奥曲肽的质量浓度在4.38~219 μg/mL范围内与色谱峰面积成良好的线性关系,相关系数为0.9999,检出限为1.1 ng,定量限为2.19 ng。测定结果的相对标准偏差为0.26%~0.46% (n=5),加标回收率为97.41%~100.26%。该方法简便、快速、准确,适用于奥曲肽原料药与制剂的定量分析。     

Lipase－Catalyzed Resolutions of both Enantiomers of Ornidazole and Secnidazole

The resolutions of both enantiomers of the ornidazole and sec-nidazole were achieved with high enantiomeric excesses (ee>99%) by acylation of the corresponding racemates with vinylac-etate in the presence of lipase Amano AK (from Pseudomonassp.). The assignments of the absolute configurations of (+) or(-)-ornidazole and secnidazole are described.     

Stereoselective Determination of Ornidazole Enantiomers in Human Plasma and Urine Samples by Chiral LC: Application to Pharmacokinetic Study

A stereoselective liquid chromatographic method to determine the enantiomers of ornidazole in human plasma and urine has been developed and validated. After addition of the internal standard (naproxen), samples were acidified and extracted with diethyl ether. The separation was performed on a Chiralcel OB-H column, using hexane-ethanol- glacial acetic acid (94:6:0.08, v/v) as the mobile phase. The method was validated for specificity, linearity, sensitivity, precision, accuracy and stability. For each enantiomer of ornidazole, linear calibration curves were obtained over the concentration range of 0.16–20 μg mL^?1 in plasma and 0.32–20 μg mL^?1 in urine. For both enantiomers of ornidazole in plasma and urine, the coefficient of variation for precision were consistently less than 12% and accuracy were within ±14% in terms of relative error. Application of the method to a preliminary pharmacokinetic study showed that this validated method was qualified for the direct determination of ornidazole enantiomers in human plasma and urine.     

Stereoselective Determination of Ornidazole Enantiomers in Human Plasma and Urine Samples by Chiral LC: Application to Pharmacokinetic Study

A stereoselective liquid chromatographic method to determine the enantiomers of ornidazole in human plasma and urine has been developed and validated. After addition of the internal standard (naproxen), samples were acidified and extracted with diethyl ether. The separation was performed on a Chiralcel OB-H column, using hexane-ethanol- glacial acetic acid (94:6:0.08, v/v) as the mobile phase. The method was validated for specificity, linearity, sensitivity, precision, accuracy and stability. For each enantiomer of ornidazole, linear calibration curves were obtained over the concentration range of 0.16–20 μg mL⁻¹ in plasma and 0.32–20 μg mL⁻¹ in urine. For both enantiomers of ornidazole in plasma and urine, the coefficient of variation for precision were consistently less than 12% and accuracy were within ±14% in terms of relative error. Application of the method to a preliminary pharmacokinetic study showed that this validated method was qualified for the direct determination of ornidazole enantiomers in human plasma and urine.

     

一种高灵敏、多响应的Zn-MOF荧光传感器对Fe3+、2，4，6-三硝基苯酚和奥硝唑的检测

在水热条件下基于H₄bta(1,2,3,5-苯四酸)和bpy(4,4''-联吡啶)配体设计、合成了一个锌的金属有机骨架(Zn-MOF){[Zn₂(bta)(bpy)(H₂O)₂]·H₂O}_n(1),并用元素分析、红外光谱、X射线单晶衍射等对其进行了结构表征。MOF 1为三维网状结构。完全去质子化的(bta)^4-配体采用了μ₆-η¹-η²-η²-η¹螯合桥联配位方式。有意思的是,MOF 1是一种高灵敏度、选择性好、多响应的荧光传感器,可用于Fe³⁺、2,4,6-三硝基苯酚和奥硝唑的快速检测。此外还研究了1的热稳定性。