恒电流库仑分析法测定硫酸亚铁铵等基准试剂的纯度

在1．8mol／L硫酸介质中,以恒电流通过含有Mn^2＋的电解质溶液,使工作电极铂阳极上电生出Mn^3＋,Mn^3＋与溶液中待测基准试剂硫酸亚铁铵、草酸钠或草酸定量反应,以永停终点法确定库仑滴定终点,通过测量电解电流及电解时间,利用法拉弟电解定律计算基准试剂的纯度。该方法的相对误差为0．32％～0．36％,测量结果的相对标准偏差为0．045％-0．050％（n=11）。     

固载硫杂杯芳烃树脂分离富集-火焰原子吸收法测定痕置银

报道了色谱301固载硫杂杯芳烃树脂分离预富集-火焰原子吸收光谱法测定痕量银的新方法。探讨了固载硫杂杯芳烃树脂对银的吸附原理与最佳条件。将含Ag^＋试液在pH=10、温度为23±2℃的条件下恒温震荡10min，静置10min，Ag^＋可被树脂定量富集被吸附的Ag^＋可用5mL酸性硫脲（0．15mol／L HCl＋0．15mol／L硫脲）完全洗脱，洗脱液中的银用火焰原子吸收光谱法测定。该法对银的检出限为0．17μg／L（3σ，n=11）；线性范围为0．006—3mg／L。对0．18mg／L的Ag^＋标液进行7次测定，RSD=1．53％。回收率在99．9％-105．0％之间。用于“二次资源”锌矿渣和环境水样中痕量银的测定，结果满意。     

CMC-Na/TETA-B62型蛇笼树脂对Ag+、Cr3+和Hg2+的吸附性能

研究了自合成的蛇笼型螯合树脂三乙烯四胺交联甘油环氧树脂／羧甲基纤维素体系对Ag^ 、Cr^3 、Hg^2＋的吸附量，吸附动力学，等温吸附过程等静态吸附性能，同时研究了PH值等因素对吸附性能的影响。实验结果表明，该树脂对Ag^ 、Cr^3 具有较强的吸附选择性，在Ag^ 、Cr^3 、Hg^2＋3种离子共存时能选择吸附Ag^ ，其选择性系数分别为KAg/Hg^2 ＝10．31、KAg^ /Cr^3 =1.77,KCr^3 /Hg^2 =5.83。该树脂对上述3种离子的吸附量分别达2.99mmol/g、1．69mmol/g、0．29mmol/g，该类树树可用于含重金属离子污水的处理和金属离子的分离等方面。     

基于双发射免标记核酸探针的比率型荧光传感器用于银的检测

构建了一种新型免标记的双发射荧光比率核酸探针(GelRed/[G40]/Tb^3+)并用于Ag+的检测。对于GelRed/[G40]/Tb^3+探针,GelRed作为一种核酸染料嵌入到单链DNA-[G40]中,形成的GelRed/[G40]作为稳定的内置参照标准,在激发波长290 nm处,发射荧光强度固定不变的红色荧光(发射波长为635 nm),而[G40]/Tb^3+作为敏感的响应信号,随着Ag^+浓度的增加,产生的绿色荧光逐渐增强(发射波长为545 nm),[G40]/Tb3+与GelRed/[G40]发射的荧光强度比值也发生相应的改变,从而实现对Ag^+的定量检测。在优化的实验条件下,[G40]/Tb^3+与GelRed/[G40]荧光强度比值和Ag^+浓度在0~7.5μmol/L的范围内具有较好的线性关系,Ag^+检出限为0.156μmol/L。本传感器在10 min内就可完成对Ag^+的分析。方法已用于自来水样中Ag^+的检测,与ICP-MS法检测结果一致。     

青霉素裂解液的高效液相色谱分析

 利用高效液相色谱法分析测定青霉素裂解液中的主要成分 6 氨基青霉烷酸 (6 APA)、青霉素G钾和苯乙酸 ,并对副产物青霉噻唑酸进行了液相色谱的定性检测。结果表明 ,实验方法简便、快速 ,结果准确 ,可以用于 6 APA生产的质量控制。     

硫羟乳酸作为络合滴定掩蔽剂的研究

本文系统地研究了硫羟乳酸在络合滴定中的掩蔽性能。发现在ｐＨ３．０用ＥＤＴＡ滴定了Ｔｈ＾４＋时，可用它掩蔽Ｓｎ＾４＋，Ｔｌ＾３＋，Ｓｂ＾３＋，Ｂｉ＾３＋，Ｂｈ＾２＋和Ｃｕ＾２＋。在ｐＨ５．５滴定Ｙｂ＾３＋，Ｌａ＾３＋或Ｃｅ＾３＋时，可用它掩蔽Ｓｎ＾４＋，Ｔｌ＾３＋，Ｓｂ＾３＋，Ｂｉ＾３＋，Ｈｇ＾２＋，Ｃｕ＾２＋和Ｃｒ＾３＋，在ｐＨ１０．０滴定Ｍｇ＾２＋时，可用它掩蔽Ｓｎ＾４＋，Ｔｌ＾３＋，Ｓｂ＾３＋     

库仑滴定法测定烟叶提取物中茄尼醇

本文提出用库仑滴定法测定茄尼醇。以含有1mol·L－1KBr的78％（V／V）醋酸溶液为介质，以5mA恒电流为电解电流，对布尼醇进行库仑滴定，用双铂电极电流法指示滴定终点，得到满意结果．方法简便、准确，不需要标准溶液，不需要昂贵仪器。     

Zn-Al类水滑石结构正电荷对内禀电离平衡常数的影响

采用电势滴定(potentiometric titration,PT)法测定了Zn-Al类水滑石(HTlc)的零净电荷点(pHPZNC);利用电势滴定数据直接计算得到Zn-Al HTlc的内禀电离平衡常数(pKa2int)和质子吸附自由能(G0ads,2);研究了结构电荷密度(σp)对pKa2int 和G0ads,2的影响.结果表明,随σp增加, pKa2int 和G0ads,2数值均降低,说明σp越大,带正电荷的HTlc与H＋结合力越低,HTlc去质子能力越强,H＋游离出HTlc表面的趋势越大.研究发现，HTlc的pKa2int与pHPZNC之间符合关系式: pKa2int =1.372pHPZNC－3.328.     

苯甲酰化展青霉素和青霉酸的高效液相色谱紫外吸收测定法

建立了一种快速、灵敏检测痕量展青霉素（ｐａｔｕｌｉｎ）和青霉酸（ｐｅｎｉｃｉｌｌｉｃａｃｉｄ）的新方法。对酞内酰胺苯甲酰氯（４（２－ｐｈｔｈａｌｉｎｕｄｙｌ）ｂｅｎｚｏｙｌｃｈｌｏｒｉｄｅ,简称ＰＩＢ－Ｃｌ］为柱前衍生试剂同展青霉素和青霉酸衍生反应,衍生物用ＯＤＳ柱分离,乙腈－水（４７：５３,Ｖ／Ｖ）作流动相,紫外检测器检测（λ＝３００ｎｍ）。以２倍信噪比计算最低检出限,展青霉素２．０ｐｍｏｌ,青霉酸１０ｐｍｏｌ。     

超高效液相色谱-串联质谱法同时测定全血中青霉素G及其主要代谢产物

建立了同时检测全血中青霉素G及其2种主要代谢产物青霉噻唑酸和脱羧青霉噻唑酸的超高效液相色谱-电喷雾串联质谱分析方法。血样经简单的蛋白沉淀提取后,目标化合物经BEH C18色谱柱(50 mm×2.1 mm, 1.7 μm),以含0.1%甲酸溶液-乙腈为流动相,梯度洗脱分离后,选用正离子电喷雾多反应监测(MRM)模式检测。方法检出限(信噪比(S/N)为3计)为0.1～2.0 ng/mL,定量限(S/N=10)为0.5～5.0 ng/mL。各被测物的线性相关系数均大于0.9974,准确度为92.3%～105.5%,日内精密度小于10%。考察了不同储存温度(18、4、-18、-80 ℃)下全血中青霉素G及其代谢物的稳定性,结果表明随着储存温度升高和时间的延长,青霉素G的质量浓度下降明显。应用建立的方法检测了给予20 mg/kg青霉素G后的大鼠血液样本,血液中青霉素G原形药物在给药后0.5 h即消除完全(低于检出限),而其代谢物的体内消除时限可延长至36 h。所建方法对司法鉴定的适用性得到了进一步扩大,同时对食品残留检测也具有一定的参考价值。     

Determination of Procaine Penicillin G and Penicillin G by Second Derivative Spectrophotometry in Pharmaceutical Products

Abstract

“Zero-crossing” derivative spectrophotometry has been used for determining binary mixtures of penicillin G and procaine penicillin G.

The procedure is rapid, simple, nondestructive, and does not require resolutions of equations.

Calibration graphs are linear between 2.0 and 50.0 μg mL^?1 of the penicillin G at 226.0 nm, and between 2.0 and 100.0 μg mL^?1 of procaine penicillin G at 319.0 nm, in the presence of each other. A complete and exhausive statistical analysis of the experimental data was realized to demonstrate the validity of method. The method was successfully applied to assay commercial injections of these drugs.     

青霉素G亚砜对-甲氧基苄基酯的制备

青霉素亚砜;合成;青霉素G亚砜对-甲氧基苄基酯的制备     

青霉素结构的探究

青霉素是人类抗菌历史上最伟大的产物。在极其简陋的实验条件下,正是由于科学家不懈地探索,青霉素神秘的结构才逐渐展现在人类面前。现在广泛用于临床上的β-内酰胺抗生素,大都是在青霉素原有结构基础上修饰改造而来。     

氧化苏木精复合电极测定牛奶中残留青霉素

氧化苏木精复合电极测定牛奶中残留青霉素;电流型电化学生物传感器;氧化苏木精;青霉素     

高分子载体材料对青霉素酰化酶的固定化作用

介绍了天然高分子材料和合成高分子材料对青霉素酰化酶的固定化作用,着重讨论了高分子材料的制备、性质及其表面修饰对固定化酶活性和使用稳定性的影响。     

Simultaneous Determination of Procaine Penicillin G and Benzathine Penicillin G by Second Derivative Spectrophotometry

Abstract

A new method for determining the binary mixtures of procaine penicillin G and benzathine penicillin G using “zero-crossing” second derivative spectrophotometry is described. Calibration graphs were linear up to 8.80 10^?5 M for procaine penicillin G and 4.40 10^?5 M for benzathine penicillin G. The method was realized in ethanol/water medium (30 % v/v). A complete and exhaustive statistical analysis of the experimental data was realized to demonstrate the validity of method. The method was applied for determining procaine penicillin G and benzathine penicillin G synthetic mixtures with good results. The procedure does not require any separation step.     

Novel approaches to the purification of penicillin acylase

Penicillin acylase ofE. coli NCIM 2400 has been purified to homogeneity using a combination of hydrophobic interaction chromatography and DEAE-cellulose treatment. A variety of substituted matrices were synthesized using D- or DL-phenylglycine, norleucine, ampicillin, or amoxycillin as ligands, all of which retained penicillin acylase at high concentrations of ammonium sulfate or sodium sulfate. The enzyme could be eluted nonbiospecifically by buffer of lower ionic strength with over 95% recovery of the activity. Ammonium chloride, ammonium nitrate, sodium chloride, sodium nitrate, and potassium chloride were ineffective in either adsorption or elution of the enzyme on these columns. Further purification of this partially pure enzyme with DEAE-cellulose at pH 7.0–7.2 yielded an enzyme preparation of very high purity according to electrophoretic and ultracentrifugal analyses, its specific activity being as high as 37 U/mg protein. The purifiedf enzyme has a molecular weight of 67,000 a sedimentation coefficient of 4.0S, and resolves into two forms upon isoelectric focusing. Overall recoveries ranged between 75 and 85%. Ease of operation, high recoveries, high purity of the enzyme and prolonged reuse of the conjugates make the process economically feasible and possibly of great commercial importance.     

A simple colorimetric method for the assay of penicillin G salt and penicillamine by oxidation with iodate

A simple colorimetric procedure is described for determination of penicillin G salt and penicillamine. It is based on oxidation with potassium iodate at room temperature and measurement of the liberated iodine at 520 nm after extraction with carbon tetrachloride. Compared with other procedures, this method proved to be more rapid, highly reproducible and reasonably accurate. The relative standard deviation did not exceed 0.9% and 0.4% for penicillin and penicillamine, respectively. The procedure has been successfully applied to pharmaceutical preparations containing either of the two compounds.     

青霉素类药物的共振光散射光谱分析

本文研究了青霉素钠-碱性品红缔合物的共振散射光谱,建立了pH =7.5的C-L缓冲溶液中,共振光散射法测定青霉素钠的新方法.线性回归方程△IRu=1.74+5.17C,相关系数R=0.9981,检测限3.16×10-7mol/L.该方法简单快速,灵敏度高,对实际样品进行了测定,得到了令人满意的结果.