维生素B的同时测定——神经网络与紫外光谱法

研究了反向传播神经网络（ＢＰＮＮ）及改进算法，经比较发现ＢＰＮＮ在某些方面优于滤波分辨及多元校正，将其应用于多元分析及光谱定量，可不经分离同时测定Ｂ族维生素，操作简便，结果良好，从而开发一种多组分同时光谱测定新方法。     

多元校正紫外光度法同时测定甲硝唑与维生素B6

本文报道多元校正紫外光度法同时测定甲硝唑和维生素B6。首先在0．1mol／LHCl溶液中对甲硝唑和维生素B6两组分混合溶液进行分光光度法测定,然后将所得的重叠光谱数据经计算机采集后,分别用化学计量学方法中的偏最小二乘法（PLS）和主成分回归法（PCR）进行处理,并用于药物样品的测定,获得了较好的定量分析结果。该法甲硝唑和维生素B6的线性范围分别为1．0～28．0mg／L和1．0～28．0mg／L,检出限分别为0．568mg／L和0．364mg／L。     

主成分回归-紫外光度法同时测定食用香料麦芽酚和乙基麦芽酚

报道了一种快速、简便的同时测定食用香料麦芽酚、乙基麦芽酚光度法,方法基于在pH2.87的B R缓冲溶液中对麦芽酚和乙基麦芽酚两组分混合溶液进行光度测定,所得的重叠波谱数据用主成分回归法(PCR)、经典最小二乘法(CLS)和偏最小二乘法(PLS)等化学计量学方法进行处理,结果表明主成分回归法(PCR)的预报误差最小。对样品进行测定,获得了较好的定量分析结果。麦芽酚和乙基麦芽酚的线性范围均为1.0～20.0mg·L-1;检出限分别为0.4347和0 5589mg·L-1。     

维生素B的同时测定─—神经网络与紫外光谱法

研究了反向传播神经网络（ＢＰＮＮ）及改进算法，经比较发现ＢＰＮＮ在某些方面优于滤波分辨及多元校正。将其应用于多元分析及光谱定量，可不经分离同时测定Ｂ族维生素，操作简便，结果良好。从而开发了一种多组分同时光谱测定新方法。     

紫外光谱法同时测定水中苯酚、邻苯二酚和间苯二酚

苯酚、邻苯二酚和间苯二酚的紫外光谱重叠严重,难以对它们进行单个分析,因此采用紫外光谱法测定水中苯酚、邻苯二酚和间苯二酚的吸光度,并以蚂蚁算法(ACA)处理测定后的数据,得到苯酚、邻苯二酚和间苯二酚的含量.苯酚、邻苯二酚、间苯二酚的回收率分别在98.33%～101.11%、96.25%～100.56%,98.13%～102.86%之间.     

主成分回归一紫外光度法同时测定盐酸西替利嗪和苯甲酸钠

提出了一种用紫外光度法同时测定盐酸西替利嗪和苯甲酸钠的方法.在pH 4.56的B-R缓冲溶液中对盐酸西替利嗪和苯甲酸钠两组分混合溶液进行吸光度测定,所得的重叠光谱数据用主成分回归法(PCR)和偏最小二乘法(PLS)等化学计量学方法进行处理,结果表明主成分回归(PCR)的预报误差最小.对实际样品进行测定,回收率为88.8...     

单扫描示波极谱—目标因子分析法同时测定三种维生素

利用单扫示波极谱技术与目标因子分析方法在ｐＨ１０的０．１ｍｏｌ／ＬＮＨ３Ｃｌ－ＮＨ３．Ｈ２Ｏ缓冲液中，于－１．４Ｖ～－１．９Ｖ进行阴极扫描，测定了维生素混合液中的维生素ＰＰ（烟酰胺），维生素Ｂ１３（乳清酸）和维生素Ｂ１（硫胺素）。     

主成分分析同时测定多组分金属离子

将主成分分析用于同时单点pH络合滴定,可同时测定多组分金属离子。讨论了方法原理、pH值的选择,建立了主成分分析常数矩阵。对四元金属离子混合样进行了多次测定,均获得满意结果。     

pH滴定-主成分回归法同时测定酚类同系物

本文利用pH滴定－主成分回归法同时测定了苯酚、邻苯二酚、邻苯三酚的混合物，结果良好。通过交差验证法，本文还对采样区间和采样间隔作了详细讨论。     

Simultaneous Quantitation of Minoxidil and Tretinoin in Magistral and Pharmaceutical Preparations by First Derivative Spectrophotometry

Abstract

A first derivative spectrophotometry method has been developed for the simultaneous quantitation of minoxidil and tretinoin. The method is based on measuring the first derivative signals (D₁) of minoxidil and tretinoin at 290 and 351 nm, respectively, without any interference from each other, or any other coexisting materials. Beer's law was valid over the concentration range 2–10 μg/ml of minoxidil and 0.25–1.25 μg/ml of tretinoin. The proposed method has been applied successfully to the determination of some magistral and pharmaceutical preparations. Relative standard deviations for the assay of both drugs were less than 0.95%.     

Determination of Ranitidine Hydrochloride in Pharmaceutical Preparations by Ultraviolet and Visible Spectrophotometry

Abstract

Ranitidine hydrochloride in tablets (T) and injections (I) was determined by ultraviolet spectrophotometry (UVS) at 313 nm and visible spectrophotometry (VISS) at 615 nm, after reaction with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) and ferric chloride. For UVS, Beer's law was obeyed in the range 5.0 – 18.0 μg/mL. The coefficients of variation (CV) for the samples T were 0.36% and 0.71% and for the samples I were 0.51% and 0.24%. The recovery average (RA) was 99.88%. For UVS, Beer's law was observed in the range 1.44 – 5.76 μg/mL. The CV for T were 0.72% and 0.59%, and for I were 0.53% and 0.61%. The RA was 99.39%. The precision and accuracy of the two methods were compared.     

Simultaneous Determination of Atenolol and Chlorthalidone in Pharmaceutical Preparations by Capillary-Zone Electrophoresis

Abstract

A capillary zone electrophoresis (CZE) method for the simultaneous determination of the β-blocker drugs atenolol and chlorthalidone in pharmaceutical formulations has been developed. The CZE separation was performed under the following conditions: capillary temperature, 25°C; applied voltage, 25 kV; 20 mM H₃PO₄–NaOH running buffer (pH 9.0); and detection wavelength, 198 nm. Phenobarbital was used as internal standard. The method was validated and showed not only good precision and accuracy but also good robustness. The method has been successfully applied to the simultaneous determination of both atenolol and chlorthalidone in pharmaceutical tablets.     

Solid Phase Spectrophotometry for the Determination of Cobalt in Pharmaceutical Preparations

 A new sensitive method exploiting solid-phase spectrophotometry is proposed for the determination of cobalt in pharmaceutical preparations. The chromogenic reagent 1-(2-thiazolylazo)-2-naphthol (TAN) was immobilized on C18 bonded silica loaded into a home-made cell with 1.5 mm of optical path for cobalt determination. Cobalt(II) reacts with TAN on C18 material, at pH 6.0–7.5, to give a coloured complex which has maximum absorption at 572 nm. In this way, the sample was passed through the cell and Co(II) ions were quantitatively retained on the solid-phase. After the direct measurement of light-absorption in the solid phase, only the cobalt was eluted with 0.1 mol L⁻¹ hydrochloric acid. The cell was washed with water and then another sample solution could be passed through the cell. The procedure allowed the determination of cobalt in the range of 10–160 μg L⁻¹ with coefficient of variation of 4.7% (n=10) and apparent molar absorptivity of 2.62 × 10⁶ L mol⁻¹ cm⁻¹ using sample volume of 3-mL. Received May 15, 2000. Revision August 28, 2000.     

卡尔曼滤波-分光光度法用于复方雷琐辛涂剂中苯酚与间苯二酚的测定

本文研究了卡尔曼滤波-分光光度法及其在多组分混合物同时光度测定中的应用。测定复方雷琐辛涂剂中苯酚与间苯二酚,平均回收率分别为100.86%与98.76%。     

Simultaneous Determination of Adrenaline and Noradrenaline by First Derivative Spectrophotometry in a Fia Assembly

Abstract

This article deals with the design of an unsegmented-flow injection manifold for the simultaneous determination of adrenaline and noradrenaline two structurally related compounds with overlapping spectra. An FIA manifold is proposed for the simultaneous determination in which the sample solution is directly injected into a carrier-reagent stream of aqueous NaOH. The selected wavelengths (first derivative) were 394 and 342 nm, for noradrenaline and adrenaline, respectively with an integration time of 0.4 s. The calibration graphs are linear over the range 2.0–30 ppm for both drugs. The method is applied to different synthetic mixtures of both drugs.     

Determination of Steroid Hormones in Pharmaceutical Preparations by High Performance Liquid Chromatography

Abstract

The aim of this research was to standardize an high performance liquid chromatographic method for the determination of steroid hormones contained in commercially available pharmaceutical preparations. A Merck LiChrospher^® 100 RP–18 (5 μm) in LiChroCART^® (125-4) column, a rotative valve injector (20 μL loop), ambient temperature, a mobile phase consisting of water-methanol and UV detection at 254nm and 212nm make possible the quantitative determination of dexamethasone acetate, prednisone, ethynylestradiol and norgestrel contained in pharmaceutical preparations.     

Spectrophotometric Determination of Ceftazidime in Pharmaceutical Preparations Using Neocuproin as a Complexing Agent

Abstract

A simple and reproducible spectrophotometric method for the assay of ceftazidime with neocuproin-copper(II) reagent has been developed. The procedure is based on the drug in an acidic medium, subsequent formation of yellow ternary complex in citrate buffer solution (pH 4.2), and measurement at 454 nm. Beer's law is obeyed in the range 15.0–40.0 µg mL^?1 with correlation coefficient r ² = 0.9995. The procedure holds good accuracy and precision when applied to the analysis of ceftazidime in powder for injection with good recovery percent ranging from 100.17±1.0 without interference from additives.