Determination of antihypertensive mixtures by use of a chemometrics-assisted spectrophotometric method

A simple multivariate calibration method for analysis of two types of hypotensive mixture is described. The mixtures are composed of chlorthalidone with atenolol or chlorthalidone with both amiloride hydrochloride and atenolol. The components of the mixtures result in substantial spectral overlap—between 87.5 and 91.0%. Resolution of the mixtures under investigation has been accomplished mainly by using CLS and PCR methods. The components in each mixture have been simultaneously determined in three commercial dosage forms with high accuracy and without interference from commonly encountered excipients and additives. Good recoveries were obtained with both synthetic mixtures and commercial tablets. The results obtained were compared with those from pharmacopeial methods and found to be in good agreement. The results obtained from CLS and PCR were also compared with those obtained from a ¹D spectrophotometric method.     

Resolution of binary mixtures of cephalothin and clavulanic acid by using first derivative spectrophotometry

First-derivative spectrophotometric method with a “zero-crossing” technique of measurement has been used for the quantification of two-components mixtures of cephalothin and clavulanic acid. As the absorption bands of these drugs overlap, both direct and derivative spectrophotometric methods have been investigated and evaluated by a rigorous statistical analysis of the experimental data. The first-derivative spectrophotometric method was found to be more accurate, direct and reproducible. Beer's law was valid over the concentration range 2.0–28.0 mg/l for both compounds. The detection limits of cephalothin and clavulanic acid, at a 0.05 level of significance, were calculated to be 0.13 and 0.15 mg/l. The method was applied for determining these antibiotics in mixtures, some of them containing inject-able dosage forms of cephalothin, and so to determine both compounds in saline and glucosed physiological sera.     

Evaluation of computer-assisted second-derivative ultraviolet spectrophotometry for analysis of binary mixtures

Three second-derivative spectra identification (DESPI) programs have been developed. The DESPI-1 program is used for the computerized recognition of the spectral components in known binary mixtures. The DESPI-2 and DESPI-3 programs are applied to the automatic identification of unknown binary mixtures. The performances of these computer-assisted procedures are evaluated and compared for nineteen single compounds (purines and pyrimidines) and twelve binary mixtures.     

Determination of mixtures of ampicillin and cloxacillin in pharmaceuticals by second-derivative spectrophotometry

Mixtures of ampicillin-Na and cloxacillin-Na are assayed by peak-to-baseline and zero-crossing second-derivative spectrophotometry. The procedure does not require any separation step. Calibration plots are linear (r = 0.9999) up to 30 μg ml^?1 of ampicillin-Na at 216 nm and up to 40 μg ml^?1 ampicillin-Na or cloxacillin-Na at 228 nm or 248.8 nm, respectively, in the presence of one another. Detection limits at the p = 0.05 level of significance, range from 0.15 pg ml^?1 to 0.33 μg ml^?1. The method was successfully applied to commercial injections and capsules containing these penicillins.     

Determination of rhenium in the URe2 binary compound by differential spectrophotometry

A differential spectrophotometric determination of rhenium in its binary compound with uranium is described; the method is based on the action of tin(II) chloride on perrhenate in the presence of dimethylglyoxime with measurement at 445 nm. Uranium does not interfere. For solutions containing about 1 mg of rhenium, the coefficient of variation was 0.08%.     

Development and validation of chemometrics-assisted spectrophotometry and liquid chromatography methods for the simultaneous determination of the active ingredients in two multicomponent mixtures containing chlorpheniramine maleate and phenylpropanolamine hydrochloride

Multivariate spectrophotometric calibration and liquid chromatography (LC) methods were used for the simultaneous determination of the active ingredients in 2 multicomponent mixtures containing chlorpheniramine maleate and phenylpropanolamine hydrochloride with ibuprofen and caffeine (mixture 1) or with propyphenazone (mixture 2). For the multivariate spectrophotometric calibration methods, principal component regression (PCR) and partial least squares (PLS-1), a calibration set of the mixtures consisting of the components of each mixture was prepared in distilled water. A leave-1-out cross-validation procedure was used to find the optimum numbers of latent variables. Analytical parameters such as sensitivity, selectivity, analytical sensitivity, limit of quantitation, and limit of detection were determined for both PLS-1 and PCR. The LC method depends on the use of a cyanopropyl column with the mobile phase acetonitrile-12 mM ammonium acetate, pH 5.0 (25 + 75, v/v), for mixture 1 or acetonitrile-10 mM potassium dihydrogen phosphate, pH 4.7 (45 + 55, v/v), for mixture 2; the UV detector was set at 212 nm. In spite of the presence of a high degree of spectral overlap of these components, they were rapidly and simultaneously determined with high accuracy and precision, with no interference from the matrix excipients. The proposed methods were successfully applied to the analysis of pharmaceutical formulations and laboratory-prepared mixtures containing the 2 multicomponent combinations.     

Analysis of nitrate-perchlorate mixtures by difference spectrophotometry

Nitron and tetraphenylarsonium chloride react with a cobaltous salt in the presence of thiocyanate to form blue ion-association complexes, which can be extracted with organic solvents. This fact has been made the basis for the analysis of mixtures of nitrate and perchlorate by difference spectrophotometry. An aliquot of the sample solution is treated with a known excess of tetraphenylarsonium chloride to precipitate perchlorate only. After separating off the precipitate, the excess of reagent is determined in the supernatant liquid as tetraphenylarsonium cobaltothiocyanate and the perchlorate content can be found from a calibration curve. Another aliquot is treated with an excess of nitron to precipitate both anions; the excess of nitron is then determined as nitron

2. Analysis of Nitrate-Perchlorate Mixtures

     

8.

Determination of vitamins in mixtures of various composition by spectrophotometry with self-modeling curve resolution     

Yu. B. Monakhova  S. P. Mushtakova  S. S. Kolesnikova 《Journal of Analytical Chemistry》2010,65(6):588-595

A simple and reliable method for the analysis of mixtures of water- and fat-soluble vitamins in the UV spectral region has been developed using the chemometrical algorithm of self-modeling curve resolution for the decomposition of the spectra of mixtures. The influence of various factors on the result of spectra decomposition has been investigated. The proposed method has been applied to the analysis of model vitamin mixtures as well as multivitamin preparations and energetic drinks.     

9.

Rapid and accurate determination of chlorpheniramine maleate, noscapine hydrochloride and guaiphenesin in binary mixtures by derivative spectrophotometry     

Pappano NB  De Micalizzi YC  Debattista NB  Ferretti FH 《Talanta》1997,44(4):633-639

Rapid and accurate binary mixture resolution of chlorpheniramine maleate-noscapine hydrochloride and chlorpheniramine maleate-guaiphenesin, was performed. Derivative spectrophotometry, by the zero-crossing measurements, was used due to the drugs closely overlapping absorption spectra. Neither sample pretreatment nor separation were required. Linear calibration graphs of first derivative values at 268.0 and 261.0 nm for chlorpheniramine-maleate-noscapine hydrochloride and at 273.2 and 261.0 nm for chlorpheniramine-guaiphenesin were obtained vs. concentration with negligible intercept on the y-axis. Thus, the derivative spectrophotometry method was applied to the determination of these drugs in binary mixtures obtaining selectivity, accuracy and precision.     

10.

New validated liquid chromatographic and chemometrics-assisted UV spectroscopic methods for the determination of two multicomponent cough mixtures in syrup     

Hadad GM  El-Gindy A  Mahmoud WM 《Journal of AOAC International》2008,91(1):39-51

Multivariate spectrophotometric calibration and liquid chromatographic (LC) methods were applied to the determination of 2 multicomponent mixtures containing diprophylline, guaiphenesin, methylparaben, and propylparaben (Mixture 1), or clobutinol, orciprenaline, saccharin sodium, and sodium benzoate (Mixture 2). For the multivariate spectrophotometric calibration methods, principal component regression (PCR) and partial least-squares regression (PLS-1), a calibration set of the mixtures consisting of the components of each mixture was prepared in 0.1 M HCl. Analytical figures of merit such as sensitivity, selectivity, limit of quantitation, and limit of detection were determined for both PLS-1 and PCR. The LC separation was achieved on a reversed-phase C18 analytical column by using isocratic elution with 20 mM potassium dihydrogen phosphate, pH 3.3-acetonitrile (55 + 45, v/v) as the mobile phase and UV detection at 260 and 220 nm for Mixture 1 and Mixture 2, respectively. The proposed methods were validated and successfully applied to the analysis of pharmaceutical formulations and laboratory-prepared mixtures containing the 2 multicomponent combinations.     

11.

分光光度法测定薯蓣皂苷元   总被引：25，自引：0，他引：25  

王俊  杨克迪  陈钧 《分析试验室》2004,23(1):73-75

采用高氯酸反应使薯蓣皂苷元显色 ,对影响显色反应的主要因素进行了考察 ,于 41 0nm波长处对穿山龙中薯蓣皂苷元的含量进行测定 ,测定结果与高效液相色谱法相近。方法的线性范围为 3.1 2～2 1 .84μg mL ,适用于薯蓣皂苷元提取过程中的常规检测     

12.

Thermodynamic properties of binary mixtures combining two pyridinium-based ionic liquids and two alkanols     

《The Journal of chemical thermodynamics》2012

Densities and speeds of sound have been determined for the binary mixtures containing an ionic liquid (1-butyl-3-methylpyridinium tetrafluoroborate or 1-butyl-4-methylpyridinium tetrafluoroborate) and an alkanol (methanol or ethanol) over the temperature range (293.15 to 323.15) K. Excess volumes and excess isentropic compressibilities have been calculated from density and speed of sound data and correlated. All the mixtures show negative values for these excess properties. Furthermore, the isothermal (vapour + liquid) equilibrium has been measured at T = (303.15 and 323.15) K, and the corresponding activity coefficients and excess Gibbs functions have been obtained. In this case, positive excess Gibbs functions have been found. We have carried out an exhaustive interpretation of the experimental results in terms of structural and energetic effects taking also into account the thermodynamic information of pure compounds. Finally, in order to study the influence of both, the presence and the position of methyl group in the cation, we have compared the results of these systems with those obtained for the mixtures formed by 1-butylpyridinium tetrafluoroborate and methanol or ethanol.     

13.

Separation of organic binary mixtures by pervaporation     

R. Rautenbach  R. Albrecht 《Journal of membrane science》1980,7(2):203-223

Pervaporation is a membrane separation process which has the inherent advantage of excellent selectivity for a number of mixtures that are otherwise difficult to separate (e.g. azeotropic mixtures or mixtures of liquids with only small differences in vapor pressures). Important parameters for pervaporation are the operating pressure on the permeate side and the temperature drop at the membrane interface caused by the phase change from liquid to vapor. This paper presents a mathematical model for the mass transport of binary mixtures within the membrane. The calculations are based on the transport equations of Shelden and co-workers [1]. These equations were solved without any simplifying assumptions and tested experimentally with benzene—cyclohexane mixtures. The limitations of the mathematical model and possible methods of improving it are discussed. The temperature drop at the membrane interface and its influence on the rate of permeation are also examined.     

14.

荧光分光光度法对马波沙星含量的测定     

谢军 《分析试验室》2012,(7):94-96

在pH 5.0和CTMAB存在下,荧光分光光度法测定血液中的兽药马波沙星,CTMAB可增强马波沙星荧光强度1.5倍。检测线性范围为5.5×10-8～3.0×10-6mol/L,检测限为4.6×10-8mol/L,相对标准偏差为1.5%。该方法可用于血液中马波沙星测定。     

15.

Determination of mercury by atomic-absorption spectrophotometry     

Wittmann Z 《Talanta》1981,28(4):271-273

A flameless atomic-absorption system has been developed for the determination of low concentrations of mercury in gaseous, solid and liquid samples of organic and inorganic materials.     

16.

分光光度法测定高铁酸钠的浓度   总被引：3，自引：0，他引：3  

刘永春  胡弘鲲  骆明霞  谢家理 《化学研究与应用》2002,14(3):299-301

目前 ,测定高铁酸盐浓度的方法有铬酸盐法[1] 、溴酸盐法及铈酸盐法[2 ] 、量气法[3] 、直接分光光度法[4] 。铬酸盐法、溴酸盐法、铈酸盐法是基于高铁酸盐的强氧化性 ,在碱性条件下将Ｃｒ(Ⅲ )、Ａｓ(Ⅲ )、Ｃｅ(Ⅱ )等化合物氧化为对应的高价化合物 ,再用已知浓度的还原剂滴定而测定高铁酸盐的浓度。该类方法操作简单、准确度高 ,但样品用量大 ,方法的灵敏度较低 ,环境污染较严重。量气法是依据高铁酸盐与非还原性酸反应放出Ｏ2 ,通过测定放出Ｏ2 的体积 ,而测定高铁酸盐的浓度。该法简便可行 ,但装置较复杂 ,环境温度、气压对测定结果的…     

17.

Determination of molybdenum by atomic-absorption spectrophotometry     

Purushottam A  Naidu PP  Lal SS 《Talanta》1972,19(10):1193-1198

A new procedure is described for precise estimation of molybdenum by atomic-absorption spectrophotometry using an airacetylene flame. Phosphoric acid was found to be effective in suppressing interference by Fe(III), Al, Sb(III), Ca, Mg, Pb and Mn(II).     

18.

Determination of paraquat by flow-injection spectrophotometry     

E.Chico Guijarro  P. Yáñez-Sedeño  L.M.Polo Diéz 《Analytica chimica acta》1987

The flow-injection determination of Paraquat (1,1′-dimethyl-4,4′-bipyridinium) is based on its reduction with sodium dithionite in alkaline medium and detection at 605 nm. Linear calibration plots are obtained for 0.1–1.0, 1.0–10 and 5.0–30.0 mg l^?1 Paraquat, the lower limit being 40 times less than that of the usual spectrophotometric method. The method is applied to determine Paraquat in spiked potable water and potatoes after preconcentration by column ion-exchange. The determination of Paraquat in different herbicide samples yielded results in good agreement with those obtained by polarographic and manual spectrophotometric methods.     

19.

Determination of HOD by infrared spectrophotometry     

Al-Ali BI 《Talanta》1978,25(10):607-609

The concentration of HOD in biological fluids is measured by using vacuum distillation, followed by infrared spectrophotometry.     

20.

荧光分光光度法测定硫酸阿米卡星的含量     

李满秀  刘凯凯  石轶男 《分析试验室》2012,(5):44-46

阿米卡星本身在激发波长295nm,发射波长367nm处有微弱荧光。它在NaNO2存在下,氨基亚硝化为硝基,然后在弱酸条件下水解为还原糖后与乙二胺在磷酸盐缓冲液中反应会产生强荧光物质。据此建立了阿米卡星含量测定的新方法。阿米卡星在2.0×10-5～5.0×10-6 mol/L的范围内与其产物荧光强度呈现良好的线性关系,相关系数r=09952,检出限为4.2×10-7mol/L。该方法用于市售硫酸阿米卡星注射液含量的测定。     

Perchlorate			Nitrate
Taken (μg)	Found (μg)	Error (%)	Taken (μg)	Found (μg)	Error (%)
400	404	+ 1.00	248	250	+0.81
400	400	0.00	496	492	?0.81
400	400	0.00	992	992	0.00
800	796	?0.50	248	248	0.00
600	602	+0.33	248	245	?1.21
800	792	?1.25	496	498	+0.40

Determination of vitamins in mixtures of various composition by spectrophotometry with self-modeling curve resolution

A simple and reliable method for the analysis of mixtures of water- and fat-soluble vitamins in the UV spectral region has been developed using the chemometrical algorithm of self-modeling curve resolution for the decomposition of the spectra of mixtures. The influence of various factors on the result of spectra decomposition has been investigated. The proposed method has been applied to the analysis of model vitamin mixtures as well as multivitamin preparations and energetic drinks.     

Rapid and accurate determination of chlorpheniramine maleate, noscapine hydrochloride and guaiphenesin in binary mixtures by derivative spectrophotometry

Rapid and accurate binary mixture resolution of chlorpheniramine maleate-noscapine hydrochloride and chlorpheniramine maleate-guaiphenesin, was performed. Derivative spectrophotometry, by the zero-crossing measurements, was used due to the drugs closely overlapping absorption spectra. Neither sample pretreatment nor separation were required. Linear calibration graphs of first derivative values at 268.0 and 261.0 nm for chlorpheniramine-maleate-noscapine hydrochloride and at 273.2 and 261.0 nm for chlorpheniramine-guaiphenesin were obtained vs. concentration with negligible intercept on the y-axis. Thus, the derivative spectrophotometry method was applied to the determination of these drugs in binary mixtures obtaining selectivity, accuracy and precision.     

New validated liquid chromatographic and chemometrics-assisted UV spectroscopic methods for the determination of two multicomponent cough mixtures in syrup

Multivariate spectrophotometric calibration and liquid chromatographic (LC) methods were applied to the determination of 2 multicomponent mixtures containing diprophylline, guaiphenesin, methylparaben, and propylparaben (Mixture 1), or clobutinol, orciprenaline, saccharin sodium, and sodium benzoate (Mixture 2). For the multivariate spectrophotometric calibration methods, principal component regression (PCR) and partial least-squares regression (PLS-1), a calibration set of the mixtures consisting of the components of each mixture was prepared in 0.1 M HCl. Analytical figures of merit such as sensitivity, selectivity, limit of quantitation, and limit of detection were determined for both PLS-1 and PCR. The LC separation was achieved on a reversed-phase C18 analytical column by using isocratic elution with 20 mM potassium dihydrogen phosphate, pH 3.3-acetonitrile (55 + 45, v/v) as the mobile phase and UV detection at 260 and 220 nm for Mixture 1 and Mixture 2, respectively. The proposed methods were validated and successfully applied to the analysis of pharmaceutical formulations and laboratory-prepared mixtures containing the 2 multicomponent combinations.     

分光光度法测定薯蓣皂苷元

采用高氯酸反应使薯蓣皂苷元显色 ,对影响显色反应的主要因素进行了考察 ,于 41 0nm波长处对穿山龙中薯蓣皂苷元的含量进行测定 ,测定结果与高效液相色谱法相近。方法的线性范围为 3.1 2～2 1 .84μg mL ,适用于薯蓣皂苷元提取过程中的常规检测     

Thermodynamic properties of binary mixtures combining two pyridinium-based ionic liquids and two alkanols

Densities and speeds of sound have been determined for the binary mixtures containing an ionic liquid (1-butyl-3-methylpyridinium tetrafluoroborate or 1-butyl-4-methylpyridinium tetrafluoroborate) and an alkanol (methanol or ethanol) over the temperature range (293.15 to 323.15) K. Excess volumes and excess isentropic compressibilities have been calculated from density and speed of sound data and correlated. All the mixtures show negative values for these excess properties. Furthermore, the isothermal (vapour + liquid) equilibrium has been measured at T = (303.15 and 323.15) K, and the corresponding activity coefficients and excess Gibbs functions have been obtained. In this case, positive excess Gibbs functions have been found. We have carried out an exhaustive interpretation of the experimental results in terms of structural and energetic effects taking also into account the thermodynamic information of pure compounds. Finally, in order to study the influence of both, the presence and the position of methyl group in the cation, we have compared the results of these systems with those obtained for the mixtures formed by 1-butylpyridinium tetrafluoroborate and methanol or ethanol.     

Separation of organic binary mixtures by pervaporation

Pervaporation is a membrane separation process which has the inherent advantage of excellent selectivity for a number of mixtures that are otherwise difficult to separate (e.g. azeotropic mixtures or mixtures of liquids with only small differences in vapor pressures). Important parameters for pervaporation are the operating pressure on the permeate side and the temperature drop at the membrane interface caused by the phase change from liquid to vapor. This paper presents a mathematical model for the mass transport of binary mixtures within the membrane. The calculations are based on the transport equations of Shelden and co-workers [1]. These equations were solved without any simplifying assumptions and tested experimentally with benzene—cyclohexane mixtures. The limitations of the mathematical model and possible methods of improving it are discussed. The temperature drop at the membrane interface and its influence on the rate of permeation are also examined.     

荧光分光光度法对马波沙星含量的测定

在pH 5.0和CTMAB存在下,荧光分光光度法测定血液中的兽药马波沙星,CTMAB可增强马波沙星荧光强度1.5倍。检测线性范围为5.5×10-8～3.0×10-6mol/L,检测限为4.6×10-8mol/L,相对标准偏差为1.5%。该方法可用于血液中马波沙星测定。     

Determination of mercury by atomic-absorption spectrophotometry

A flameless atomic-absorption system has been developed for the determination of low concentrations of mercury in gaseous, solid and liquid samples of organic and inorganic materials.     

分光光度法测定高铁酸钠的浓度

目前 ,测定高铁酸盐浓度的方法有铬酸盐法[1] 、溴酸盐法及铈酸盐法[2 ] 、量气法[3] 、直接分光光度法[4] 。铬酸盐法、溴酸盐法、铈酸盐法是基于高铁酸盐的强氧化性 ,在碱性条件下将Ｃｒ(Ⅲ )、Ａｓ(Ⅲ )、Ｃｅ(Ⅱ )等化合物氧化为对应的高价化合物 ,再用已知浓度的还原剂滴定而测定高铁酸盐的浓度。该类方法操作简单、准确度高 ,但样品用量大 ,方法的灵敏度较低 ,环境污染较严重。量气法是依据高铁酸盐与非还原性酸反应放出Ｏ2 ,通过测定放出Ｏ2 的体积 ,而测定高铁酸盐的浓度。该法简便可行 ,但装置较复杂 ,环境温度、气压对测定结果的…     

Determination of molybdenum by atomic-absorption spectrophotometry

A new procedure is described for precise estimation of molybdenum by atomic-absorption spectrophotometry using an airacetylene flame. Phosphoric acid was found to be effective in suppressing interference by Fe(III), Al, Sb(III), Ca, Mg, Pb and Mn(II).     

Determination of paraquat by flow-injection spectrophotometry

The flow-injection determination of Paraquat (1,1′-dimethyl-4,4′-bipyridinium) is based on its reduction with sodium dithionite in alkaline medium and detection at 605 nm. Linear calibration plots are obtained for 0.1–1.0, 1.0–10 and 5.0–30.0 mg l^?1 Paraquat, the lower limit being 40 times less than that of the usual spectrophotometric method. The method is applied to determine Paraquat in spiked potable water and potatoes after preconcentration by column ion-exchange. The determination of Paraquat in different herbicide samples yielded results in good agreement with those obtained by polarographic and manual spectrophotometric methods.     

Determination of HOD by infrared spectrophotometry

The concentration of HOD in biological fluids is measured by using vacuum distillation, followed by infrared spectrophotometry.     

荧光分光光度法测定硫酸阿米卡星的含量

阿米卡星本身在激发波长295nm,发射波长367nm处有微弱荧光。它在NaNO2存在下,氨基亚硝化为硝基,然后在弱酸条件下水解为还原糖后与乙二胺在磷酸盐缓冲液中反应会产生强荧光物质。据此建立了阿米卡星含量测定的新方法。阿米卡星在2.0×10-5～5.0×10-6 mol/L的范围内与其产物荧光强度呈现良好的线性关系,相关系数r=09952,检出限为4.2×10-7mol/L。该方法用于市售硫酸阿米卡星注射液含量的测定。