流动注射在线过滤稀释原子吸收测定药物制剂中安乃近的方法研究

提出了测定安乃近的FI-AAS分析新方法。此法基于在适当酸度条件下安乃近将Cu^2 还原为Cu^ ，新生成的Cu^ 与SCN^-生成沉淀，经流动注射在线过滤稀释，以AAS法测定反应剩余Cu^2 的量来间接测定安乃近的含量。安乃近的浓度在2-100mg/L范围内吸收值呈良好的线性关系。回收率为97.0%-102.5%，采样频率为100次/h。     

流动注射梯度稀释-原子吸收光谱法间接测定异烟肼

本法基于在中性条件下，异烟肼与Cu^2 定量形成难溶于水的配合物，经流动注射梯度稀释-AAS测定上清液中剩余的Cu^2 的量间接测定异烟肼的含量。异烟肼在50-600mg/L范围内与吸光度呈良好的线性关系，R^2=0．9998；采样频率120次／h，回收率为98．3％-103．2％。     

间接原子吸收法测定药物制剂中布洛芬的含量

鉴于布洛芬(简称BLF)在医药上的应用价值，其含量的测定一直为人们所关注。目前该药的测定方法有酸碱滴定法、色谱法、紫外分光光度法及差示扫描量热法等，而用原子吸收法测定，尚未见报道。本实验基于BLF在适当的酸性条件下与Cu^2 形成络合物，通过CHCl3萃取，测定水相中剩余Cu^2 的含量来利用络合反应-原子吸收分光光度法测定药物制剂中BLF的含量。用于实际样品的测定，获得满意结果。     

离子色谱法测定复方卡托普利片中卡托普利和氢氯噻嗪的含量

建立离子色谱法测定复方卡托普利片中卡托普利和氢氯噻嗪含量的方法。在色谱柱为IonPacSCS1(4mm×250mm),保护柱为IonPacSCG1(4mm×50mm),淋洗液为甲烷磺酸(4mmol/L)+乙腈(26%),流速1.0mL/min,柱温35℃,进样量7μL,紫外检测波长215nm的条件下,测定结果表明,卡托普利和氢氯噻嗪在0.5～25μg/mL范围内线性关系良好,相关系数r分别为0.9997、0.9999,回收率分别为98.11%、94.24%。方法操作简单,灵敏度高、准确、重现性好,可用于复方卡托普利片的质量控制。     

基于含氟表面活性剂修饰的金纳米粒子测定卡托普利

在较高离子强度和一定温度下,卡托普利能引起非离子表面活性剂FSN-100修饰的14nm金纳米粒子胶体溶液快速聚集,引起金纳米粒子在519nm处的吸光度降低,而在640nm处的相对吸光度成线性增加.据此,建立了一种光度测定卡托普利的新方法.卡托普利药片制剂中常见赋形剂,如淀粉、糊精、葡萄糖、果糖、麦芽糖、蔗糖、明胶、山梨醇、乳糖等对本实验没有干扰.本方法具有快速、简便、选择性高等优点,线性范围为2.0～12.5μg/mL,卡托普利检出限(S/N=3)为1.25μg/mL.该方法成功用于药片制剂中卡托普利的测定,回收率在99%到103%之间.     

低压离子色谱-化学发光联用在线检测水中痕量铜

低压离子色谱化学发光方法在线检测Cu^2 ，利用草酸作为色谱柱的洗脱液，研究了分离条件、发光条件及二者的匹配方式等因素对分离检测的影响，测定Cu^2 的线性范围为0．4－6mg／L；检测限为0．1mg/L，方法用自来水及地表水中Cu^2 的分析测定。     

原子吸收光度法间接测定甲基托布津的含量

用标准Cu^2 溶液和样品中的甲基托布津在氨碱性环境下作用，产生定量沉淀，离心分离未反应的Cu^2 ，用原子吸收分光光度计测定Cu^2 浓度可间接求得样品中的甲基托布津的含量。本法的检出限10mg/L；测定范围为10-120mg/L；RSD小于3．2％。本方法的测定结果与络合滴定法与分光光度法的结果能很好地符合。     

新荧光试剂5-(4-氟苯偶氮)-8-水杨醛缩氨基喹啉荧光法测定痕量铜

合成了新荧光试剂5-(4-)氟苯偶氮)-8-水杨醛缩氨基喹啉(p-FPSAQ)，探讨了与Cu^2 反应的荧光性质。在pH8．5的缓冲体系中，p-FPSAQ与Cu^2 形成2：1络合物；线性范围5．0～90．0ng／L，检出限为2．43ng／L，可用于自来水中铜的测定。     

一种新型三角架罗丹明B荧光探针对Cu～（2＋）识别性能研究

设计、合成了一种新颖的三角架结构罗丹明B衍生物（2）.在乙醇-水（8/1,V/V）介质中,用Tris-HCl控制体系pH为6.8,观察到Cu^2＋对化合物2的荧光及紫外-可见吸收增强性能,同时化合物2对Cu^2＋具有较高的选择性响应.选择最大激发和发射波长为557/577nm,测定了探针2（1.00×10^-5mol·L^-1）对Cu^2＋响应的校准曲线,线性范围为0.10～10.00×10^-5mol·L^-1,相关系数R^2=0.9964（n=15）,检出限为1.129×10^-7mol·L^-1,平行测定5次的相对标准偏差（R.S.D.）为2.2%;以557nm为最大吸收波长测定紫外吸收,Cu^2＋响应的浓度线性范围为0.50～25.00×10^-5mol·L^-1,相关系数R^2=0.9948（n=13）,检出限为3.338×10^-7mol·L^-1.     

线性扫描伏安法同时测定铬、镉、铜

在苯胲类试剂-乙醇-醋酸铵体系中，Cr(Ⅵ)、Cd^2 、Cu^2 都能产生灵敏的阴极络合吸附波。Cr(Ⅵ)的二次导数峰电位在-0．92V(vs．SCE)处，在0．0017～0．67μg／mL范围内与峰电流成正比；Cu^2 的峰电位在-0．21V(vs．SCE)处，在0．0083～5．8μg／mL范围内与峰电流成正比；Cd^2 的峰电位在-0．70V(vs．SCE)处，线性范围为0．0017～0．117μg／mL。这一方法为工业废水中重金属的同时测定提供了可靠、灵敏的检测方法。     

Indirect Determination of Captopril with Sodium Nitrate and Thiocyanate by Floatation Separation of Copper

A new method for indirect determination of captopril (CPT) with NaNO₃ and NH₄SCN by floatation and separation of copper has been studied. In the weak acid, a small amount of Cu(II) can be reduced to Cu(I) by CPT, then Cu(I) reacted with the SCN, which can float on the surface of the liquid phase with NaNO₃. A good linear relationship is observed between the floatation yield (E%) of Cu(II) and the amount of captopril. The linear range is 2?32 mg/L. On the ground, captopril can be indirectly determined by determining E(%) of Cu(II). The method is simple, rapid, reliable and has good selectivity. The developed method can be applied to indirect determination of captopril with satisfactory results.     

Determination of captopril and its mixed disulphides in plasma and urine by high-performance liquid chromatography

A high-performance liquid chromatographic method has been developed which enables sensitive determination of captopril and its mixed disulphides in plasma and urine after oral administration of a new antihypertensive agent, 1-(D-3-acetylthio-2-methylpropanoyl)-L-prolyl-L-phenylalanine (DU-1219, I). Captopril is derivatized with a new reagent, N-(4-benzoylphenyl)maleimide and the derivative is extracted with chloroform and assayed using a liquid chromatograph equipped with an ultraviolet detector at 254 nm. Mixed disulphides of captopril with thiol compounds such as cysteine, glutathione and plasma proteins are reduced with tributylphosphine to form captopril, followed by derivatization with N-(4-benzoylphenyl)maleimide. Accurate determinations are possible over a concentration range of 10-500 ng/ml captopril in plasma, and 100-2500 ng/ml captopril in urine. The coefficients of variation of captopril in plasma (200 ng/ml) and urine (500 ng/ml) are 3.7% and 2.6%, respectively, and those of mixed disulphides of captopril are similar to those of captopril. Plasma levels and urinary excretion of captopril and its mixed disulphides in healthy volunteers following single oral administration of I (50 mg) have also been determined.     

间接原子吸收法测定药物制剂中利血生的含量

提出了利血生的间接原子吸收法，该法基于利血生在碱性介质中的分离－产物半胱氨酸在适当的PH条件下与铜离子生成灰色沉淀，通过测定上清液中铜的含量来间接测定利血生的含量，在法在10－100mg/L范围内呈良好的线性关系（r=0.9992),回收率为98．5％－101．6％。该法可成功地用于药物制剂中利血生的测定。     

表面活性剂形成的微环境对SOD和水杨酸铜配合物 SOD样活性的影响

合成水杨酸铜配合物,用X射线衍射测定了它的结构,并用改进的NBT法研究了它和SOD在pH=7.8磷酸缓冲液、表面活性剂CTAB、TX-100形成效团、层状液晶中的SOD样活性。结果表明,在不同微环境中SOD和水杨酸铜配合物的SOD样活性顺序是：在pH=7.8磷酸缓冲液中＞在CTAB胶团中＞在CTAB层状液晶中;在TX-100有序组合体中＞在CTAB有序组合体中。加入少量三氯化镨(PrCl3)也能抑制NBT的还原。而且,PrCr3对NBT的抑制作用与Cu(Ⅱ)配合物的抑制作用是叠加的。     

铜合金中铜的示波滴定—四苯硼钠法

本文报道了铜合金中铜的示波滴定方法。样品酸溶后，用抗坏血酸还的Ｃｕ＾２＋为Ｃｕ＾＋，加入过量的四苯硼钠，在ＰＨ５－６的ＨＡｃ－ＮａＡｃ缓冲溶液中，定量形成Ｃｕ－ＴＰＢ沉淀，过量的ＴＰＢ＾－，以Ｔｌ＾＋标准溶液进行示波滴定，铜合金中共存元素不干扰测定。铜的测定回收率９９．８％－１００．１％。进行了多种铜合金中铜含量的测定，结果令人满意。     

Parafac and PLS applied to determination of captopril in pharmaceutical preparation and biological fluids by ultraviolet spectrophotometry

A new ultraviolet spectrophotometric method has been developed for the direct qualitative determination of captopril in pharmaceutical preparation and biological fluids such as human plasma and urine samples. The method was accomplished based on parallel factor analysis (PARAFAC) and partial least squares (PLS). The study was carried out in the pH range from 2.0 to 12.8 and with a concentration from 0.70 to 61.50 microg ml(-1) of captopril. Multivariate calibration models PLS at various pH and PARAFAC were elaborated from ultraviolet spectra deconvolution and captopril determination. The best models for this system were obtained with PARAFAC and PLS at pH = 2.04 (PLS-PH2). The applications of the method for the determination of real samples were evaluated by analysis of captopril in pharmaceutical preparations and biological (human plasma and urine) fluids with satisfactory results. The accuracy of the method, evaluated through the root mean square error of prediction (RMSEP), was 0.58 for captopril with PARAFAC and 0.67 for captopril with PLS-PH2 model. Acidity constant of captopril at 25 degrees C and ionic strength of 0.1 M have also been determined spectrophotometrically. The obtained pKa values of captopril are 3.90 +/- 0.05 and 10.03 +/- 0.08 for pKa. and pKa2, respectively.     

Kinetic Monte Carlo study of submonolayer heteroepitaxial growth comparing Cu/Ni and Pt/Ni on Ni(100)

The surface patterns formed during submonolayer Cu/Ni and Pt/Ni heteroepitaxy upon a Ni(100) substrate have been investigated by kinetic Monte Carlo (KMC) simulations. The two-dimensional (2D) KMC simulations are based upon rate constants for a complete nearest-neighbor set of 729 uncorrelated Cu or Pt atoms and/or Ni site-to-site hopping mobilities. The rate constant activation energies are determined by classical-potential total-energy calculations using an embedded-atom method potential function from the literature. We find that diffusion of Cu atoms occurs at a faster rate and Pt atoms at a slower rate than that of Ni atoms on the flat Ni(100) surface, and the initial nucleation and growth patterns of 2D islands and the kinetic versus thermodynamic control of the growth vary as a consequence. In the temperature and deposition time regime in which we work, the Cu/Ni systems show less than random mixing, while the Pt/Ni systems show more than random mixing. The Cu/Ni system has bonding energies that result in a tendency to segregate toward subdomains of pure Ni and Cu, though kinetic effects in the epitaxy trap the development of the system at small subdomain sizes. The Pt/Ni system has bonding energies giving a tendency to intermix completely, while epitaxial kinetic effects modestly interfere with the complete mixing. The kinetically determined island morphologies under various Cu/Ni and Pt/Ni compositions and deposition rates differ substantially over time periods that are long on the deposition time scale, and therefore the island patterns can become frozen in place.     

Sensitive method for determination of captopril in biological fluids by gas chromatography-mass spectrometry

A sensitive method for the determination of captopril in blood and urine by gas chromatography-mass spectrometry is described. In order to prevent oxidative degradation of captopril, its sulph-hydryl group was immediately protected by treatment with N-ethylmaleimide (NEM), and the resulting NEM adduct was then converted into the bis(pentafluorobenzyl) derivative. Derivatized captopril was separated on a 2% OV-1 column, exhibiting a single peak of the correct theoretical shape. The detection limit was estimated to be 100 pg by using S-benzylcaptopril as an internal standard. The blood level and urinary excretion of unchanged captopril orally administered to dogs were determined by the proposed method. In addition, epimerization of the proline moiety and formation of the sulphoxide or sulphone through the esterification step are also described.     

Stereoisomeric purity determination of captopril by capillary gas chromatography.

The GC method developed for the stereoisomeric purity determination of captopril is based on the combined information derived from the analyses of the captopril sample on two GC systems, one with a chiral and the other with an achiral column. The limit of detection has been determined to be 0.02% (w/w) for (R,S) or (S,R) and 0.03% for (R,R), with corresponding minimum quantifiable levels of 0.08% and 0.09%.