碘离子选择性电极间接电位法测定鱼油的磺值

用碘离子选择性电极间妆电位法测定了鱼油及其它油脂的碘值。确立了电位法的最佳测定条件。在１０＾－５－１０＾１ｍｏｌ／Ｌ范围内，磺离子浓度与电位间有良好的线性关系。与测定油脂磺值的国家标准方法进行了比较，误差小于６％，该法具有并便、快速的优点。     

磷酸氢钙中氟化物检查方法改进

目的改进磷酸氢钙中氟化物的检查方法。方法采用银-氯化银电极为参比电极,氟离子选择电极法测定磷酸氢钙中氟化物的含量。结果氟离子浓度在10~1 000 ng.mL-1时,电位值差值(△mv)与氟离子浓度(ng.mL-1)的对数值呈良好线性关系。结论该法操作简便、结果准确可靠,重现性良好。     

利君沙有效成分琥乙红霉素的电位分析法测定

目的:研制一种琥乙红霉素(EES)的聚氯乙烯(PVC)膜选择性电极,以用于利君沙有效成分的快速测定。方法:以琥乙红霉素与四苯硼钠形成的缔合物为电活性物质研制了琥乙红霉素 PVC 膜离子选择性电极,用于琥乙红霉素制剂的测定。结果:该电极的 Nernst 线性响应范围为2.8×10~(-5)～3.0×10~(-4)mol·L~(-1);斜率为44mV/pc;检测下限为1.00×10~(-5)mol·L~(-1);平均回收率达96.5%。结论:该电极制作方法简单,响应迅速,重现性较好,用于利君沙中有效成分琥乙红霉素的测定,其结果与电位滴定法、抗生素微生物检定法基本吻合。     

氧瓶燃烧法-氟离子选择电极法测定司氟沙星片的含氟量

目的:用氟离子选择性电极测定经氧瓶燃烧破坏后的司氟沙星含量,建立一种利用氟离子选择性电极进行定量分析的新方法。方法:药物经氧瓶燃烧有机破坏,使氟离子游离于吸收液中,对吸收液进行适当处理后用氟离子选择电极测其电位值,根据标准曲线测定含量。结果:司氟沙星片中氟离子浓度在2.0×10~(-6)～2.0×10~(-2)mg·ml~(-1)范围标准曲线线性良好,r=0.999 8,方法回收率为99.48%。结论:该方法简单准确,可以用来进行司氟沙星的含量测定。     

涂丝型双嘧达莫选择电极的研制与应用

报道了一种以双嘧达莫与碘分子形成的缔合物为电活性物的PVC膜双嘧达莫涂丝选择电极,测定了双嘧达莫片的含量。电极的线性响应范围为1.0×10-2~4.0×10-5mol/L,级差电位为56mV/pC,检测限为2.6×10-5mol/L。该电极响应迅速,重现性好,结果与药典法相符。     

人血浆皮质醇放射免疫测定(摘要)

近十多年来,用同位素作为示踪剂的方法测定肾上腺皮质功能已显示出灵敏度高、特异性强的优点。目前采用的有~(125)碘-皮质醇放射免疫测定法和~3氢-皮质醇竞争性蛋白结合分析法。最近用酶标法和液体层析法测定血浆皮质醇,其灵敏度与同位素法相似,前者只需分光光度计在一般实验室即可进行。本文采用~(125)碘-皮质醇试剂箱对74名健康献血员分别于上午8、9、10时取血检查皮质醇,经     

雷尼替丁的单扫描示波极谱测定法

在 pH 5的 HOAc-NaOAc 缓冲溶液中,雷尼替丁呈现两个示波极谱峰,其峰电位分别为-0.98及-1.47 V。第一个峰的峰电流与雷尼替丁浓度在15×10~(?)～2.4×10~(-4)mol/L 的范围内呈线性关系。用于测定片剂中雷尼替丁的含量,结果与药典法一致。     

测定三碘(或四碘)甲状腺原氨酸钠中碘氨基酸杂质的反相高压液相层析法

美国药典规定用纸层析测定三碘甲腺氨酸钠(NaT_3)中二碘及四碘甲腺氨酸(T_2、T_3)杂质,但当杂质量很少时,该法不灵敏,不能准确测定;对四碘甲腺氨酸钠(MaT_4)尚无杂质检出方法。本文用反相高压液相层析法可在30分钟内准确、灵敏地测定标准品中小于75×10~(-12)克分子的杂质和分解产物。     

过硫酸钾存在下极谱催化波法测定氯胺酮

目的:建立一种简便、灵敏的测定氯胺酮(KET)新方法。方法:基于氧化剂存在时 KET 产生的极谱催化波,用线性扫描极谱法快速测定 KET。结果:在1.46×10~(-2)mol·L~(-1)Britton-Robinson(pH 2.09)支持电解质中,KET 于-1.44V(vs.SCE)处产生1个还原波。引入过硫酸钾后,该还原波峰电流增加约10倍,峰电位基本不变,产生一极谱平行催化波。其二阶导数峰峰电流与 KET 的浓度在1.0×10~(-9)～1.0×10~(-7)mol·L~(-1)范围内呈线性关系(r=0.9995,n=11),检出限为4.0×10~(-10)mol·L~(-1)。结论:该方法可用于药剂中 KET 含量的测定。     

用奴佛卡因阳离子选择膜电极测定药物制剂中的奴佛卡因

本文报道了用奴佛卡因与四苯硼酸盐或二苦胺的离子缔合络合物制成液膜离子选择电极,在室温下,以直接电位法或四苯硼酸钠的电位滴定法测定药物制剂中的盐酸奴佛卡因(对氨基苯甲酸-2-二乙胺基乙酯的盐酸盐),较之常用的紫外分光光度法或光密度法,     

碱性锌还原法测定3-乙酰氨基-2,4,6三碘苯甲酸(乌乐康)的碘含量

肾造影剂3-乙酰氨基-2,4,6三碘苯甲酸(鸟乐康),其碘含量测定的方法,美典XV版⑴及N.N.R.⑵都采用鹼性溶液中以高锰酸钾氧化法(该药品种较新尚未见诸其他药典),这个方法的缺点是分析週期太长(需在水浴上迥流18小时),有时尚有偏低的现象,由于存在上述缺点,故不能适应车间生产上的需要。     

Potentiometric and voltammetric determination of methimazole

The determination of methimazole was investigated by potentiometric titration in an alkaline medium involving its reaction with iodine and square wave voltammetry (SWV) in 0.1 mol/l Tris–HCl buffer at pH 7.2. In potentiometric titration, the range of determination was 10–500 μmol. A stoichiometric reaction was obtained within the concentration range 0.75–1.25 mol/l of sodium hydroxide by potentiometric titration. A linear calibration graph was obtained over the concentration range 1–700 μmol/l by SWV. The lowest concentration of methimazole detected was 0.5 μmol/l. The relative standard deviations (R.S.D.) were 0.81% in potentiometric titration and 2.89% in square wave voltammetric analysis of thyromazol tablets. The data showed that potentiometric titration using iodine in sodium hydroxide can be used for the determination of methimazole in drug samples without prior separation.     

Potentiometric Titration of 2-Thiouracils

A new method is presented for the determination of 100–500 μmol of 6-methyl-2-thiouracil and 6-benzyl-2-thiouracil which utilises their reaction with iodine in an alkaline medium with potentiometric end-point detection. Elaborated methods were applied to the determination of 2-thiouracils in drugs.     

聚维酮碘栓的稳定性

采用多元回归模型不同条件下的加速试验,考察聚维酮碘栓稳定性并预测有效期,室温储存期为２６个月。     

Potentiometric determination of famotidine in pharmaceutical formulations

Two new potentiometric methods for determination of famotidine in pure form and in its pharmaceutical tablet form are developed. In the first method, the construction of plasticised poly(vinyl chloride) (PVC) matrix-type famotidine ion-selective membrane electrode and its use in the potentiometric determination of famotidine in pharmaceutical preparations are described. It is based on the use of the ion-associate species, formed by famotidine cation and tetraphenyl borate (TPB) counterion. The electrode exhibited a linear response for 1 x 10(-3)-1 x 10(-5) M of famotidine solutions over the pH range 1-5 with an average recovery of 99.26% and mean standard deviation of 1.12%. Common organic and inorganic cations showed negligible interference. In the second method, the conditions for the oxidimetric titration of famotidine have been studied. The method depends on using lead(IV) acetate for oxidation of the thioether contained in famotidine. The titration takes place in presence of catalytic quantities of potassium bromide (KBr). Direct potentiometric determination of 1.75 x 10(-2) M famotidine solution showed an average recovery of 100.51% with a mean standard deviation of 1.26%. The two methods have been applied successfully to commercial tablet. The results obtained reveal good percentage recoveries, which are in good agreement with those obtained by the official methods.     

PVC membrane sensor for diclofenac: applications in pharmaceutical analysis and drug binding studies

A PVC membrane sensor for diclofenac based on its ion pair complex with silver is prepared. The influences of membrane composition (PVC, plasticizer, and ion pair complex), pH of test solution and presence of other anions on the performance of the electrode were investigated. The optimized membrane demonstrates Nernstian response (-58.9 +/- 0.2 mV/decade) for diclofenac anions over a wide linear range from 5.2 x 10(-5) to 1.1 x 10(-2) M at 25 +/- 1 degree C. The potentiometric response is independent from pH at the range of 6.0-9.5. The advantages of the proposed sensor are: easy preparation, good selectivity and fast response time. It was successfully used for determination of diclofenac in pharmaceuticals and also in potentiometric study of interaction of diclofenac with bovine serum albumin. The results of diclofenac assay with the proposed sensor were in good agreement with the official HPLC method.     

压电振荡频移法测定微量有机碘药物

研究了用镀金石英压电晶体测定微量有机碘药物与碘化物的条件与方法。在CCl₄中,晶体电极的振荡频率随吸附碘量的增加而降低。在被萃取水相碘化物浓度为1×10^-7～3×10^-6M范围内,振荡频移值与浓度成正比;AF(Hz)=22.2×10⁷C(M)。除溴以外,其它物质无显著干扰。振荡频率可用氨水回复。研究了影响因素与吸附机理。方法可用于有机碘化合物中含碘量,水溶液、尿液及血液中微量有机碘药物等的测定。     

电位滴定法测定西地碘含片中碘的含量

目的:建立测定西地碘含片中碘含量的方法。方法:用水与10%醋酸溶液溶解样品,预加一定体积的硫代硫酸钠滴定液(0.01 mol.L-1),用碘滴定液(0.005 mol.L-1)回滴体系中剩余的硫代硫酸钠,采用电位滴定法测定西地碘含片中碘的含量。结果:绘制出的滴定曲线,滴定突跃明显;重复测定同一批样品,其RSD=0.12%(n=6);平均回收率为99.91%、100.10%、100.05%。结论:该方法简便、灵敏度高、准确可靠,可用于西地碘含片的质量控制。     

异戊巴比妥选择电极的研制及初步应用

An amobarbital-selective electrode based on amobarbital-triheptyldodecylammonium ionpairs in nitrobenzene was prepared and studied. The electrode showed a linear response to amobarbital anion within 2 × 10^-2～5 × 10^-5M concentration range in 0.1M Na₂CO₃ medium. The slope of the electrode was 57 mV/ decade and the limit of detection was 2 × 10^-5M. The electrode can be used for the determination, of amobarbital in drug-substances by direct potentiometry or potentiometric titration with standard solution of sulfuric acid. Dissociation of electroactive material in liquid ion exchanger is also discussed in the paper.     

Chemically prepared silver electrode for determination of N-acetyl-L-cysteine by flow-injection potentiometry

This paper describes the use of the silver electrode by means of chemical pretreatment of the electrode surface with mercuric(II) chloride solution and potassium iodide solution in flow injection analysis (FIA). The electrode is used as a potentiometric sensor for the indirect determination of NAC in a carrier stream containing iodine. A one-channel flow system that consists of a peristaltic pump, injection valve, a silver wire electrode and a saturated calomel reference electrode (SCE) was used. Some typical FIA parameters such as flow rate, tube length and composition of the carrier stream were varied. The electrode is further characterised by a constant linear response within the concentration range for NAC between 4.0 x 10(-6) and 1.0 x 10(-3) M at the slope of 60.6 +/- 1.0 mV/p(NAC). Some pharmaceutical products containing NAC were also tested. These results can be compared to the results obtained by the direct potentiometric titrations with silver nitrate and are also in good agreement with values declared by pharmaceutical manufacturers.