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Chinese Chemical Letters 2006年第10期17卷 1347-1350页

作者： Ali NIAZI zadeh YAZDANIPOUR ohammad GOODARZI amidreza KAMKAR Ali RAFINEJAD Department of Chemistry Faculty of Sciences Azad University of Arak Arak Iran Department of Pharmacy Faculty of Pharmacy Azad University Tehran Iran

This work reports the spectrophotometric simultaneous determination of zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ） in pharmaceutical preparation, using orthogonal signal correctionpartial least squares （OSC-PLS）. All the factors affecting on the sensitivity were optimized and the linear dynamic range for determination of these metals was found. The PLS modeling was used for the multivariate calibration of the spectrophotometric data. The OSC was used for preprocessing of data matrices and the prediction results of model. The experimental calibration matrix was designed by measuring the absorbance over the range 450-570 nm for 21 samples of 0.05-1.05, 0.10-1.10 and 0.05-1.05μg·mL^-1 of zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ）, respectively. The RMSEP for zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ） using OSC-PLS were 0.0164, 0.0132, 0.0146, respectively. The proposed method was successfully applied the determination of zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ） in pharmaceutical preparations.

关键词： Zinc（Ⅱ） manganese（Ⅱ） iron（Ⅱ） spectrophotometric OSC-PLS pharmaceutical

spectrophotometric Determination of Trace Chromium(VI) in Mass Chromium(III)

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Chinese Chemical Letters 2001年第7期12卷 635-636页

作者： Zi Gang XU Xian Hong WEN Qing Zhou WU Center of Analysis&Testing Zhejiang UniversityHangzhou 310027

The method for the sepration and determination of trace Cr(VI) exiting in mass Cr(III) has been researched. The method is highly sensitive and less interference, but is simple and useful for analysis trace Cr(VI).

关键词： spectrophotometric Cr(VI) Cr(III) diphenyl carbazide(DPC) 4-methyl-benzene sulfonic acid

Azeotropic mixture used for development and validation of Lornoxicam in bulk and its tablet dosage form by spectrophotometric method

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Journal of Pharmaceutical Analysis 2012年第4期2卷 306-309页

作者： Prajesh Prajapati Vipul Vaghela Deepak Rawtani Harshad Patel Jasmin Kubavat Dharmendra Baraiya Department of Pharmaceutical Analysis Institute of Research and DevelopmentGujarat Forensic Sciences UniversitySector-18ANr.Police bhavan A.R.College of Pharmacy and G.H.Patel Institute of Pharmacy

A novel,safe,economic and sensitive method of spectrophotometric estimation has been developed using Azeoptropic mixture (water∶methanol:60∶40,v/v) for the quantitative determination of Lornoxicam,a practically water-insoluble drug.Hence,Lornoxicam stock solution was prepared in Azeoptropic mixture.Lornoxicam showed maximum absorbance at 383 nm.Beer's law was obeyed in the concentration range 4-24 μg/mL with regression coefficient of 0.999.The method was validated in terms of linearity (R2=0.999),precision (CV for intra-day and inter-day was 0.28 0.68 and 0.12-0.92,respectively),accuracy (98.03-100.59％ w/w) and specificity.This method is simple,precise,accurate,sensitive and reproducible and can be used for the routine quality control testing of the marketed formulations.

关键词： Analgesic Chlortenoxicam Lornoxicam Oxicam spectrophotometric Azeotropic mixture

spectrophotometric Determination of the pKa, Isosbestic Point and Equation of Absorbance vs. pH for a Universal pH Indicator

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American Journal of Analytical Chemistry 2014年第17期5卷 1290-1301页

作者： L. E. Vidal Salgado C. Vargas-Hernández Laboratory of Optical Properties of Materials (POM) National University of Colombia Manizales Colombia

The pKa and the isosbestic point of the universal pH indicator Carlo Ebra 1-11 (catalog number 45712) were determined using UV-Vis spectrophotometry. Aqueous buffer solutions with pHs ranging from 3.83 to 10.85 were mixed. Four methods—two graphical and two mathematical— were used to estimate the acid dissociation constant (pKa) and isosbestic point using absorbance measurements. The equation for the dependence of the absorbance on pH at λ = 600 nm was obtained using calibration curves. The resulting average pKa of the four methods was 8.277 with a standard deviation of 0.1728. The results obtained using the mathematical methods were very similar, with a deviation of 0.0014;the average pKa determined using these methods was 8.263 ± 0.001. The literature contains no previous reports of the pKa of this indicator. The isosbestic point occurs at a wavelength of 494 nm, with an absorbance of 0.46.

关键词： Design of Buffers spectrophotometric Titration Determination of pKa Isosbestic Point Universal pH Indicator

spectrophotometric Characterization of the Complex Generated in Solution for the Reaction of H[Ru(III)Cl<sub>2</sub>(H<sub>2</sub>EDTA)] Complex with AETS Modifier Agent

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Open Journal of Synthesis Theory and Applications 2014年第4期3卷 37-43页

作者： Angélica M. Lazarin Rosana Lázara Sernaglia Departamento de Química Universidade Estadual de Maringá Maringá Brazil

spectrophotometric method was used to evaluate the kinetic of the complex formation from the reaction between H[Ru(III)Cl2(H2EDTA)] and the modifier agent [3-(2-aminoethyl)aminopropyl] trimethoxysilane (AEATS) (μ = 0.50 mol.dm-3 with NaCF3COO, 298.15 K), in pseudo-first order conditions. These studies showed that the reactions are successives producing several species influenced by the concentrations ratio. The electronics spectrum of all solutions showed a band in 457 nm with variable molar absorptivity (ε).

关键词： [3-(2-Aminoethyl)aminopropyl]trimethoxysilane H[Ru(III)Cl2(H2EDTA)] Complex spectrophotometric Method Molar Absorptivity

spectrophotometric Determination of Lamivudine Using Chloranilic Acid and 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)

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American Journal of Analytical Chemistry 2011年第7期2卷 849-856页

作者： Kenneth C. Madu P. O. Ukoha A. A. Attama 不详

A spectrophotometric method for the assay of lamivudine in pure form and in dosage form was developed in this study. The method was based on charge-transfer complex formation between the drug, which acted as n-donor while chloranilic acid and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) acted as a p-acceptor in a non-aqueous solvent in each case. Chloranilic acid was found to form a charge-transfer complex in a 1:1 stoichiometry with lamuvudine (lamivudine-chloranilic acid) with a maximium absorption band at 521 nm. Also, DDQ was found to form a charge-transfer complex in a 1:1 stoichiometry with lamivudine (lamivudine-DDQ) with a maximium absorption band at 530 nm. The pH was obeyed at acid range. The complexes obeyed Beer’s law at a concentration range of 0.04 - 0.28 mg/ml. The thermodynamic parameters calculated at different temperatures included the molar absorptivity, association constant, free energy change, enthalpy and entropy. The proposed method has been conveniently applied in the analysis of commercially available lamivudine tablet with good accuracy and precision.

关键词： Charge-Transfer Complexation Chloranilic Acid DDQ Lamivudine spectrophotometric Determination Thermodynamic Studies pH Pharmaceutical Formulation

spectrophotometric Determination of Fluoride in Groundwater Using Resorcin Blue Complexes

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American Journal of Analytical Chemistry 2012年第9期3卷 651-655页

作者： Zaher Barghouthi Sameer Amereih National Agricultural Research Center (NARC) Jenin Palestine Palestine Technical University-Kadoori Tullkarm Palestine

New simple and sensitive spectrophotometric determination of fluoride in drinking groundwater has been developed using aluminium-resorcin blue complex. The method is based on the reaction of fluoride with the coloured complex to produce colourless aluminium fluoride complex and releasing of the free ligand. The relationship of the reaction of flu-oride with the complex is sixth-order polynomial function. The reaction reaches equilibrium at fluoride concentration of 0.054 mM. The equilibrium constant (Keq) was calculated as 1.12 × 1014. Beer-Lambert law is obeyed in the range 0.0 - 0.024 mM of fluoride (0.0 - 1.0 mg·L-1). The molar absorptivity at 502 nm is 6.45 × 103 L·mol-1·cm-1. Fluoride concentration higher than 1.0 mg·L-1 can be measured after proper dilution. The sensitivity, detection limit, quantitation limit, and the percentage recovery of 0.75 mg·L-1 fluoride for the method were found to be 0.357 μg·ml-1., 0.07 mg·L-1, 0.2 mg·L-1, and 101.1 respectively.

关键词： Fluoride Groundwater spectrophotometric Method Aluminium Resorcin Blue Complex

β－CORRECTION　spectrophotometric　DETERMINATION　OF　ALUMINIUM，　USING　THE　AL（Ⅲ）－PF－OP　REACTION

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Chinese Chemical Letters 1994年第8期5卷 679-680页

作者： Hong Wen GAO Feng ZOU and Peng Fei ZHANG(Huaibei Environmental Monitoring Centre, Huaibei, Anhui Province, 235000Huaibei Beer-Manusfacturing Plant, Anhui Province,235000 Department of Chemistry,Huaibei Coal Teachers College, Anhui Province, 235000)

Aluminium has been determined by β-correction spectrophotometer with phenylfluorone (PF)and a non-ionic surfactant, emulsifying OP in PH 8 ammoniacal buffer solution. β-correction spectrophotometric method can eliminate completely the effect of excess PF to increase the analytical sensitivity and decrease error. The results have Shown that Beer's law was obeyed over the concentration range 0-15μg Al (Ⅲ)/25ml and the relative standard deviation was less than 3.3%.

关键词： OP spectrophotometric DETERMINATION OF THE USING CORRECTION ALUMINIUM PF

Application of Total Error Strategy in Validation of Affordable and Accessible UV-Visible spectrophotometric Methods for Quality Control of Poor Medicines

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American Journal of Analytical Chemistry 2015年第2期6卷 106-117页

作者： Jérémie Kindenge Mbinze Jean Nsangu Mpasi Elza Maghe Sébastien Kobo Rodrigue Mwanda Guy Mulumba Jacquie Bolavie Bolande Trésor Menanzambi Bayebila Maguy Borive Amani Philippe Hubert Roland Djang’eing’a Marini University of Liege (ULg) Department of Pharmacy CIRM Laboratory of Analytical Chemistry Li&egrave ge Belgium Laboratory of Drug Analysis Faculty of Pharmaceutical Sciences University of Kinshasa Kinshasa Democratic Republic of Congo Laboratory Service Institute of Research in Science of Health Kinshasa Democratic Republic of Congo Faculty of Medicine and Pharmacy University of Kisangani Kisangani Democratic Republic of Congo

In the framework of fighting against the poor quality medicines sold in developing countries using classical analytical methods easily accessible in those countries, four UV-Visible spectrophotometric methods for one antimalarial (quinine) and two antibiotics (amoxicillin and metronidazole) have been developed and validated according to the total error strategy using the accuracy profiles as a decision tool. The dosing range was 2 - 10 μg/mL (for quinine sulfate in tablet), 4 - 12 μg/mL (for quinine bichlorhydrate in oral drop-metronidazole benzaote in oral suspension) and 15 - 35 μg/mL (for amoxicillin trihydrate in capsule). The validated methods were then applied in determining the content of some analogous medicines sold in the Democratic Republic of Congo. Thus, the proposed UV-Visible spectrophotometric methods are simple and suitable to quantify quinine, amoxicillin and metronidazole in different pharmaceutical forms.

关键词： Poor Quality Medicines UV-Visible spectrophotometric Methods Quinine Amoxicillin Metronidazole Validation Total Error Accuracy Profiles

A Novel spectrophotometric Method for Determination of Five 1,4-Dihydropyridine Drugs in Their Tablets and Capsules Using Vanillin Reagent

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American Journal of Analytical Chemistry 2013年第3期4卷 148-157页

作者： Mohamed A. El Hamd Sayed M. Derayea Osama Hassan Abdelmageed Hassan F. Askal Department of Pharmaceutical Analytical Chemistry Faculty of Pharmacy Al-Azhar University Assiut Egypt Department of Pharmaceutical Analytical Chemistry Faculty of Pharmacy Assiut University Assiut Egypt Department of Pharmaceutical Analytical Chemistry Faculty of Pharmacy Minia University Minia Egypt Pharmaceutical Chemistry Department Faculty of Pharmacy King Abdulaziz University Jeddah KSA

A selective and new spectrophotometric method is described for determination of five 1,4 dihydropyridine drugs (1,4- DHP);namely nifedipine (NIF), nicardipine (NIC), nimodipine (NIM), felodipine (FEL) and amlodipine (AML). The method is based on a coupling reaction between the cited drugs and vanillin reagent in acidic condition. Under optimized conditions, the red coloured products were measured at 500 nm for NIF, NIC, NIM and FEL or at 479 nm for AML. Molar absorptivities were ranged from 0.575 × 104 - 1.065 × 104 l·mol-1·cm-1, Beer’s law was obeyed at 5 - 70 μg/mL concentration range and the limit of detection was ranged from 0.150 - 1.500 μg/mL. The proposed method was successfully extended to pharmaceutical preparations tablets and capsules and comparison by Student’s t-test and variance ratio F-test showed no significant difference.

关键词： spectrophotometric Method 1 4-DHP Validated Selective Vanillin Reagent