Gran电位滴定法测定盐酸雷尼替丁的含量

因盐酸雷尼替丁和AgNO3发生沉淀反应,故本文采用Gran电位滴定法对盐酸雷尼替丁的含量进行了测定,方法的RSD为0．24%,平均回收率为99．78%,结果表明：该法简便、快速,结果令人满意。     

用 pAg 及 pX 电极作混合卤化物体系分析

用离子选择性电极测定各种试样中的卤化物已有不少介绍,但都因测定体系比较简单,且分析手续冗长,致使应用范围受到限制。本文根据具体试样的分析要求,利用pAg和pX(X为氯、溴、碘)电极,按Gran作图法、二次导数电位滴定法及     

乳酸环丙沙星的示波极谱滴定

１引言 乳酸环丙沙星（ＣＰＲＬ）为第三代氟喹诺四类抗生素,目前,其含量的测定主要有非水滴定法、紫外分光光度法、ＨＰＬＣ、极谱法等,但未见有示波极谱滴定法的报道。本法用四苯硼钠（Ｎａ－ＴＰＢ）作沉淀剂,在弱酸性（ｐＨ＝５．１）条件下与乳酸环丙沙星作用生成沉淀,过滤后,用硫酸亚铊标准溶液回滴滤液中过量的Ｎａ－ＴＰＢ,以ＴＰＢ在示波极谱图［ｄＥ／ｄｔ＝ｆ（Ｅ）］中的切口消失指示滴定终点。本法仪器简单,操作方便,取样量小,图形直观,终点敏锐,用于原料药样品的测定有良好的准确度和重现性,其结果与非水滴定法…     

离子选择电极法中两次加人标准法的计算图

在离子选择电极法中,采用加入标准法进行分析,常可减小试样组分变动的影响。目前应用较多的是一次加入标准法(借助于计算公式或Gran图)和连续加入标准法(借助于Gran图)。但是,无论是用计算公式或Gran图进行计算,均需事先测定电极的能斯特(Nernst)斜率。为了使Gran图适用于不同能斯特斜率的离子选择电极,我们曾提出用△E或ApX作图的改进的Gran图,但仍需事先测定电极的能斯特斜率。两次加入标准法是根据连续两次加入相同体积     

离子电极互为参比连续标准加入法的研究

离子选择电极分析中,为了消除液接电位导致的误差,可利用另一离子电极作为参比电极,只要在试液中保持该离子的活度恒定即可。采用同价态离子电极互作参比电极时,能以标准比较法测定试液中相应离子的活度或浓度比,还可用标准加入法或Gran作图法分别测定相应离子的浓度。标准加入法不必考虑加入的标准液的稀释影响,直接用下式计算。     

计算机辅助Gran图解法测定铝的方法研究

通过Visual Basic语言编制了Gran绘图程序。在pH4.4时,滴定体系中加入乙醇和KCl,利用氟铝滴定曲线的数据,经Gran作图确定滴定终点,求得配位反应和沉淀反应的平均配位数。讨论了pH和乙醇含量对测定的影响。本法用于水泥标样中铝的测定,结果较为满意。     

乳酸环丙沙星单扫描示波极谱法研究

研究了乳酸环丙沙星的极谱伏安行为，在ｐＨ＝８．３的０．０２ｍｏｌ／Ｌ，ＮＨ４Ｃｌ－ＮＨ３．Ｈ２Ｏ底液中，乳酸环丙沙星能产生１个灵敏的还原峰，峰电位为－１．６１Ｖ，其导数峰高与浓度在３．９×１０＾－８～１．８×１０＾－６ｍｏｌ／Ｌ和１．８×１０＾６～１．１×１０＾－５ｍｏｌ／Ｌ范围内呈现良好的线性关系，相关系数ｒ＝０．９９９７，检测下限为２．５×１０＾－８ｍｏｌ／Ｌ，用于乳酸环丙沙星注射液的测定，相     

同个线性电位滴定的计算机程序

本文拟介绍两个自Gran和Ingman公式引出的线性电位滴定的BASIC程序,可以通过CASIO PB—700机快速处理数据、打印计算结果和作出图形,以应用于分析化学沉淀、络合滴定等实验中。 1.Gran线性电位滴定在本法中常用到下述关系式:V=AX+B,式中V是加入滴定剂体积,X是V和原电池电动势E的函数,A是     

离子色谱柱后补液-积分脉冲安培法检测阿立哌唑中三乙胺残留

采用离子色谱柱后补液-积分脉冲安培法建立了测定阿立哌唑原料药中三乙胺残留量的新方法。色谱柱为Dionex IonPac CS17(4 mm×250 mm),保护柱为Dionex IonPac CG17(4 mm×50 mm)。对淋洗液的浓度、检测电位和柱后补液流速进行了优化选择,确定淋洗液为30 mmol/L甲烷磺酸,流速为1.0 mL/min;柱后补液为500 mmol/L NaOH溶液,流速为0.2 mL/min;检测电位为氨基酸电位。结果表明,三乙胺在0.1315~1.315 mg/L范围内线性关系良好(R2=0.9994),加标回收率在101.7%~105.9%之间,相对标准偏差(RSD)为1.9%,建立的方法适用于阿立哌唑原料药中三乙胺的残留量测定。     

直接进样-GFAAS法测定有机原料药中的钯

建立了直接进样-GFAAS法快速测定有机原料药中的残留Pd。考察了石墨炉干燥灰化程序及其对药物溶解溶剂的影响,并与微波消解法测定结果比较。采用适当溶剂溶解3种不同性质的药物后,在优化的石墨炉升温程序下,GFAAS法测定的检测限为0.71~1.49 ng/mL,定量限为2.35~4.95 ng/mL,RSD为0.8%~2.3%,平均回收率为99.5%~99.8%。方法可用于测定有机原料药中残留的Pd。     

环丙沙星在BTR缓冲液中的紫外光谱性质研究与应用

研究了不同缓冲溶液 ,不同pH介质中环丙沙星的紫外光谱性质 ,提出在BrittonRobinson(BTR)缓冲溶液中为紫外分光光度法测定环丙沙星的最佳条件 .在吸收波长 2 77nm处 ,测得其表观摩尔吸收系数为 2 .6 3× 10 4L/mol.cm ,浓度在 3.0～ 2 3.0mg/L范围内 ,吸收度与浓度符合比尔定律 ,该法成功用于药物制剂中环丙沙星含量的测定 ,结果满意     

Automatic flow system titration based on multicommutation for spectrophotometric determination of total acidity in silage extracts

A multicommutated flow titration procedure is proposed for the spectrophotometric determination of total acidity in silage extracts. The flow network comprises a set of 3-way solenoid valves, computer-controlled to provide facilities to handle the titrand, titrant, and carrier solutions by using a single pumping channel. The procedure is based on the volumetric fraction variation approach that maintains the same volume of titrand solution and varies the titrant solution step by step, to provide determination without the use of an analytical curve. The procedure is implemented by using phenolphthalein as an external indicator; the proposed algorithm was able to titrate silage extracts presenting different color intensities. Sample solutions with concentrations ranging from 10(-3) to 10(-1) mol/L total acidity could be analyzed by using 10(-2) mol/L sodium hydroxide as the titrant solution. Other advantages include a relative standard deviation of <1.0% (n = 4) for a typical silage extract solution containing 26 mmol/L total acidity; an analytical throughput of 16 determinations per hour was also achieved. Accuracy was assessed by processing a set of silage extract solutions and comparing the results with those obtained by using the conventional potentiometric titration procedure. No significant difference at the 95% confidence level was observed.     

Differential electrolytic potentiometric titration method for the determination of ciprofloxacin in drug formulations

A simple and rapid differential electrolytic potentiometric titration method for the determination of ciprofloxacin was developed. The work is based on the fast complexation reaction between iron(III) and ciprofloxacin in a ratio of 1:3, respectively, in sulfuric acid media of 0.09 mol dm⁻³. Among the electrodes tested silver amalgam electrodes were found to be a suitable indicating system. By applying a current density of 0.5 μA cm⁻² to these electrodes and using iron(III) solution of 0.097 mol dm⁻³ as a titrant, normal titration curves were obtained. The method was successfully applied for the determination of ciprofloxacin in drug formulations as low as 4.0 ppm.     

碳糊电极阳极吸附伏安法测定环丙沙星

报道了用碳糊电极阳极吸附伏安法测定环丙沙星的新方法.在 0. 40mol/L的NH4Ac HAc(pH4. 30)缓冲液中,使用JP 303极谱分析仪,环丙沙星在碳糊电极 (CPE)上有一灵敏的吸附伏安氧化峰,峰电位为1. 12V(vs.SCE).该氧化峰的二阶导数峰电流与环丙沙星的浓度在 8. 0×10-9 ~8. 0×10-7 mol/L(富集 90s)范围内成良好的线性关系,相关系数为 0. 998 8,检出限为 4. 0×10-9 mol/L(S/N=3,富集 110s).探讨了环丙沙星在碳糊电极上的伏安性质和电极反应机理,并且成功应用于人体尿样中环丙沙星含量的测定.加入回收实验,回收率在95. 5%至 103. 9%之间.     

极谱双点滴定法测定奎宁类药物

本文提出以0.1 mol/KI、0.025％聚乙烯醇为底液,以CdCl_2标准溶液为滴定剂,用极谱双点滴定法测定奎宁。该方法具有简便、快速等优点。     

Analysis of various very slightly water soluble drugs in micellar medium

A potentiometric and/or visual method for the determination of sulphamethoxazole (SULF) in pure form in the range of 5.3 x 10(-5) to 5.0 x 10(-4) mol/L is proposed. To enhance the solubility, the determination has been carried out in a micellar medium formed by an aqueous 5.0 x 10(-2) mol/L N-hexadecyl-N,N,N-trimethyl ammonium bromide (CTAB) solution which increases the dissociation constant K(alpha) of SULF about tenfold. The titration is performed with NaOH (2.5 x 10(-3) or 5.0 x 10(-2) mol/L) and the end-point is determined by the second derivative graph. The results agree with those obtained by the official method of the USP XXIII. The method is simple, accurate, economical and can successfully replace the more complicated, more expensive and time-consuming existent procedures which are carried out in a non-aqueous medium.     

2-羟基萘甲醛苯甲酰腙衍生物对Al~(3+)的裸眼识别和荧光传感

设计合成了化合物4-羟基苯甲酰-(2-羟基萘甲醛)腙(L)探针,经金属离子识别研究发现探针L对Al~(3+)具有良好的荧光增强识别效果且不受其它金属离子的干扰,且识别过程中溶液的颜色发生了明显变化,可以实现Al~(3+)的可视法检测,核磁滴定、job-plot、基质辅助激光解吸电离飞行时间质谱(MALDI-TOF)等实验结果显示,探针L与Al~(3+)以摩尔比2∶1的方式进行配位。通过对紫外滴定数据的非线性拟合分析,探针L与Al~(3+)的结合常数为1.3×10~4L/mol,最低检测限为3.71×10~(-6)L/mol。因此,该腙类衍生物作为Al~(3+)的荧光及比色探针,识别体系线性范围较宽,检测限低,在痕量Al~(3+)的检测方面具有潜在的应用价值。     

Simple and cost-effective determination of ciprofloxacin hydrochloride by electrical micro-titration

By employing an electrical micro-titration system, in which a capacitively coupled contactless conductivity detector(C4D) was used to monitor the reaction process in real time, herein a novel method for determining ciprofloxacin hydrochloride(CIPHCl) was developed for the first time. Mode 1: Standard CIPHCl solutions at different concentrations were loaded into reaction cells, respectively, and were titrated with standard Ag+. Upon the titration, the formation of a precipitate alters the number of ions in the solution, raising the change of conductivity, which was monitored by a special C~4 D to construct a titration curve. The endpoint of the titration was located from the peak of the curve. Between the elapsed time and the initial concentration of titrand, a linear relationship was established over the range of2.0–8.0 mmol/L. Mode 2: Standard Fe~(3+) took the place of Ag~+, and was used as titrant to recognize ciprofloxacin contributed to the formation of complexation, which also resulting a change of solution conductivity. Under optimized conditions, a working range of 1.0–5.0 mmol/L CIPHCl was found. Because the reaction solutions were isolated from the working electrodes, this pioneer work shows significant simplicity and cost-effectiveness, by eliminating the requirements for detector exchange/renewal between different measurements, and by involving no auxiliary chemicals. Both of the two approaches were applied successfully to determine CIPHCl in tablet samples. And the results were in good agreement with those obtained by reference method.     

修饰铂电极-示波双电位滴定法测定Zn(Ⅱ)

制备了锌修饰铂电极,建立了一种新的测定Zn(Ⅱ)的示波双电位滴定法。在六次甲基四胺溶液(1.0mol/L)中(pH=5.5),用制备的修饰铂电极作为双指示电极,以EDTA标准溶液滴定Zn(Ⅱ),利用示波器屏幕上荧光点的显著最大位移指示滴定终点。在3.0×10-4～2.0×10-3mol/L的浓度范围内,Zn(Ⅱ)的回收率为99.9%～100.2%。该修饰电极具有良好的稳定性和重现性,对Zn(Ⅱ,1.0×10-3mol/L)溶液连续11次测定,所得终点电位值均在10.1mV左右,其相对标准偏差(RSD)为0.5%。用来测定含锌的实际样品,其结果与指示剂法测定的值基本一致。