bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atomic Simulations of Aurivillius Oxides: Bi3TiNbO9, Bi4Ti3O12, BaBi4Ti4O15 and Ba2Bi4Ti5O18 Doped with Pb, Al, Ga, In, Ta
Authors: Rosyidah Afifah , Onggo Djulia , Khairurrijal  , Ismunandar  
Published: May 2015

AbstractThe Aurivillius oxides were originally of interest for their ferroelectric properties and have recently been explored in the field of oxide ion conductivity. Atomistic simulation methods have been carried out for Bi3TiNbO9, Bi4Ti3O12, BaBi4Ti4O15 and Ba2Bi4Ti5O18 doped with Pb, Al, Ga, In, Ta to determine defect energy in the materials by employing efficient energy minimization procedures. The calculations rest upon the specification of an interatomic potential model, which expresses the total energy of the system as a function of the nuclear coordinates. The Born model framework, which partitions the total energy into long‐range Coulombic interactions and a short‐range term to model the repulsions and van der Waals forces between electron charge clouds, is employed. This is embodied in the GULP simulation code. Dopant solution energy versus ion size trends are found for both isovalent and aliovalent dopant incorporation at Bi and Ta sites. Trivalent dopants (Al, Ga, In) and Pb are more favorable on the Bi site, whereas Ta dopants preferentially occupy the Ti site.
Kinetic Spectrophotometric Determination of Ascorbic Acid in Pharmaceutical Samples by Oxidation of Ponceau 4R by Hydrogen Peroxide
Authors: Grahovac Zora M. , Mitić Snežana S. , Pecev Todor G. , Pecev Emilija T. , Pavlović Aleksandra N. 
Published: May 2015

AbstractA new sensitive and simple kinetic method is developed for determination of traces of ascorbic acid based on its activated effect on oxidation of trisodium‐2‐hydroxy‐1‐(4‐sulphonato‐1‐naphthylazo)naphthalene‐6,8‐disulphonato (red artificial color Ponceau 4R) by hydrogen peroxide, in the presence of Cu(II) as catalyst, in borate buffer. The reaction is followed spectrophotometrically by tracing the oxidation product at 478.4 nm within 1 min after addition of H2O2. The optimum reaction conditions are: borate buffer (pH = 11.00), Ponceau 4R (9.6·10−6 mol/L), H2O2 (2·10−2 mol/L), Cu(II) (8·10−7 mol/L) at 22 °C. Following this procedure, ascorbic acid can be determined with a linear calibration graph up to 1.76 ng/mL and a detection limit of 0.28, based on 3S criterion. The relative error ranges between 6.77‐1.66% for the concentration interval of ascorbic acid 1.76‐17.61 ng/mL. The effects of certain foreign ions upon the reaction rate were determined for an assessment of the selectivity of the method. The method was applied for determination of ascorbic acid in pharmaceutical samples, and spectrophotometric method was used like an comparative method.
Polarographic (DCP & DPP) Determination of Ellagic Acid in Strawberries & Pharmaceutical Formulations
Authors: Thakur Kirti , Pitre K.S. 
Published: May 2015

AbstractDirect Current (DC) and Differential Pulse (DP) Polarographic methods have been developed for the qualitative as well as quantitative analysis of ellagic acid in plant products (i.e. strawberries) and pharmaceutical formulations (Ellagic insurance formula). Ellagic acid produces a well‐defined polarographic wave/peak in pyridine hydrochloride at pH 6.8 ± 0.1 with E1/2 /Ep = −1.298 V vs. SCE.The wave/peak height is found to be proportional to the concentration of ellagic acid. The developed procedure was used for the analysis of ellagic acid in an extract of strawberries (Fragaria × ananassa) and pharmaceutical formulations. Statistical treatment of the observed polarographic data revealed high accuracy and good precision of determination.The work has been supplemented by FTIR screening of the sample. The percentage of ellagic acid in pharmaceutical formulations was determined by the developed method, which is in close agreement with the labeled amount.
Genetic‐Algorithm‐Based Wavelength Selection in Multicomponent Spectrophotometric Determination by PLS: Application on Ascorbic Acid and Uric Acid Mixture
Authors: Khajehsharifi Habibllah , Pourbasheer Eslam 
Published: May 2015

AbstractGenetic algorithm (GA) is a suitable method for selecting wavelengths for partial least squares (PLS) calibration of mixtures with almost identical spectra without loss of prediction capacity using the spectrophotometric method. In this study, the concentration model is based on absorption spectra in the range of 200‐320 nm for 25 different mixtures of ascorbic acid (AA) and uric acid (UA). The calibration curve was linear over the concentration range of 1‐15 and 2‐16 μg mL−1 for ascorbic acid and uric acid, respectively. The root mean square deviation (RMSD) for ascorbic acid and uric acid with GA and without GA were 0.3071 and 0.3006, 0.3971 and 0.7063, respectively. The proposed method was successfully applied to the simultaneous determination of both analytes in human serum and urine samples.
Synthesis and Reactions of Some Novel Triazolo‐, Azolo‐, Tetrazolo‐Pyridopyrimidine and Their Nucleoside Derivatives
Authors: Abu‐Zied Kh. M. , El‐Gazzar A. B. A. , Hassan N. A. 
Published: May 2015

AbstractPyridopyrimidine reacted with aromatic aldehydes afforded the arylhydrazone 2a,b which could be cyclized into the pyrido[2,3‐d][1,2,4]triazolo[4,3‐a]pyrimidine 3a,b, with formic acid, and carbon disulphide to give pyrido[2,3‐d][1,2,4]traizolo[4,3‐a]pyrimidine 4, 5. Reaction of 1 with nitrous acid afforded tetrazolo[1,5‐a]pyrido[2,3‐d]pyrimidine 6, which was reduced by zinc dust to give 2‐amino‐pyrido‐[2,3‐d]pyrimidine 7. Finally the reaction of 2‐hydrazino 1 with D‐xylose or D‐glucose afforded the acyclic N‐nucleoside 8, 11 which were converted into tetra/penta O‐acetate acyclic C‐nucleoside 9, 12 in acetic anhydride/pyridine. De‐acetylation of compounds 9, 12 afforded C‐nucleosides 10, 13.
Oxidation of Organic Substrates Using Two Triethylammonium Halochromates(VI), (C2H5)3NH[CrO3X], (X=F, Cl) Supported on Silica Gel
Authors: Ghammamy Shahriare , Dastpeyman Samaneh 
Published: May 2015

AbstractTriethylammonium fluorochromate(VI), (C2H5)3NHCrO3F, TriEAFC and triethylammonium chlorochromate(VI), (C2H5)3NHCrO3Cl, TriEACC were prepared, supported on silica gel and used to quantitatively oxidize a number of organic substrates. These supported triethylammonium halochromates are versatile reagents ensuring effective oxidation of organic compounds, in particular of alcohols, under mild conditions. The durability, ease of work up and efficiency of TriEAFC and TriEACC are considerably increased upon their absorption on silica gel.
Adsorptive Voltammetric Behaviors of Resveratrol at Graphite Electrode and its Determination in Tablet Dosage Form
Authors: Liu Jin‐Xia , Wu Yan‐Ju , Wang Fei , Gao Lin , Ye Bao‐Xian 
Published: May 2015

AbstractThe adsorptive voltammetric behavior of resveratrol was studied at a graphite electrode in B‐R buffer (pH = 6.0) solution using adsorptive cyclic voltammetric technique. The oxidation of resveratrol is an irreversible adsorption controlled process. The oxidation mechanism was proposed and discussed in this work. The dependence of the current on pH and the concentration and nature of buffer were investigated to optimize the experimental conditions for the determination of resveratrol. It was found that in the range of 8.0 × 10−9 ∼ 2.0 × 10−6 mol/L, the currents measured by differential pulse voltammetries presented a good linear property as a function of the concentrations of resveratrol. In addition, validation parameters, such as reproducibility, sensitivity and recovery were evaluated as well. The proposed method was also successfully applied for the determination of resveratrol in Chinese patent medicine with good results.
Study of Complex Formation between 5,7‐Diiodo‐8‐hydroxyquinoline and Zn2+, Cd2+, Pb2+ and Tl+ Cations in Binary Non‐Aqueous Solvents Using Square Wave Polarography Technique (SWP)
Authors: Nezhadali Azizollah , Langara Padideh , Hosseini Hassan Ali 
Published: May 2015

AbstractThe complexation reaction between Zn2+, Pb2+, Cd2+ and Tl+ cations by 5,7‐diiodo‐8‐hydroxyquinoline (IQN) was studied in the Dimethylformamide /Acetonitril (DMF‐AN) binary system using square wave polarography technique. The stoichiometry and stability of the complexes were determined by monitoring the shifts in half‐wave or peak potential of the polarographic waves of metal ions against the ligand concentration. The stoichiometry of the complexes was found to be 1:1. The results obtained show that there is an inverse relationship between the formation constant of the complexes and the donor number of solvent base on the Guttmann donocity scale. In all cases the formation constants increased with increasing amounts of AN in these binary systems. The selectivity order for IQN complexes with the cations is Zn2+ > Pb2+ > Cd2+ > Tl+.
Extraction and Spectrophotometric Determination of Diclofenac in Pharmaceuticals
Authors: Kormosh Zh. O. , Hunka I. P. , Bazel Ya. R. 
Published: May 2015

AbstractA new simple, rapid and sensitive spectrophotometric method has been developed for the determination of diclofenac sodium (Dicl) in pharmaceutical preparations. This method is based on the reaction of diclofenac sodium with an analytical reagent 1,3,3‐trimethyl‐5‐thiocyanato‐2‐[3‐(1′,3′,3′‐trimethyl‐3′‐H‐indol‐2′‐ylidene)‐propenyl]‐indolium cloride (TIC) at pH 8.0‐11.0 and the extraction of ion associate colored complex. Optimal conditions for the complex formation between Dicl and TIC were studied. This ion associate complex (1:1) was detected and extracted with toluene and an absorption maximum at 566.2 nm against a blank reagent. The calibration graph was linear from 0.9‐11.0 μg/mL of diclofenac and the detection limit was 0.86 μg/mL.
Synthesis of N‐Tosylhomosphinganine and N‐Tosylsedridine
Authors: Chang Meng‐Yang , Lin Chun‐Yu , Wu Tsun‐Cheng , Sun Pei‐Pei 
Published: May 2015

AbstractA straightforward synthesis of N‐tosylhomosphinganine and N‐tosylsedridine has been achieved from trans‐4‐hydroxyproline by Grignard addition, regioselective Baeyer‐Villiger reaction, cross or ring‐closing metathesis and hydrogenation as the key steps.
Practical Preparation of 2‐Halomethyl‐Allyl Carboxylates
Authors: Sun Chong‐Si , Cheng Hsiu‐Yi , Lin Yu‐Shiang , Hou Duen‐Ren 
Published: May 2015

AbstractAn improved, efficient preparation of 2‐(halomethyl)allyl carboxylates starting from diethyl bis(hydroxymethyl)malonate and hydrobromic acid is reported. The allylic halogen of 2‐(chloromethyl)acrylate and 2‐(bromomethyl)acrylate are readily exchanged during esterification.
An Expedient Synthesis of Novel N,N′‐Diglycosylguanidine Derivatives in the Presence of Hg(II)
Authors: Chen Hong‐Mei , Li Gen , Cao Ling‐Hua 
Published: May 2015

AbstractThe reactions of N,N′‐diglycosythiourea with 2‐amino‐benzothiazoles in the presence of Hg(II) (HgCl2 or HgO) for the synthesis of N‐(4/6‐substituted‐benzothiazol‐2‐yl)‐N′,N″‐diglycosylguanidines have been reported.
Deprotection of Oximes, Phenylhydrazones, Semicarbazones and Thiosemicarbazones to the Corresponding Carbonyl Compounds Using Cetyltrimethylammonium Peroxodisulfate as a New and Selective Oxidizing Agent
Authors: Norouzi Mohammad , Tajbakhsh Mahmood , Alinezhad Heshmatollah , Urimi Azade Geran 
Published: May 2015

AbstractCetyltrimethylammonium peroxodisulfate (CTA)2S2O8 was quantitatively prepared and used for the deprotection of oximes, phenylhydrazones, semicarbazones and thiosemicarbazones to the corresponding carbonyl compounds in acetonitrile. Its agent is more efficient and has advantages over similar reagents in terms of the amount of oxidant, short reaction time, simple work up, and high yield.
Sol‐Gel‐Derived Biosensor Based on Plant Tissue: The Inhibitory Effect of Atrazine on Polyphenol Oxidase Activity for Determination of Atrazine
Authors: Majidi Mir Reza , Asadpour‐Zeynali Karim , Gholizadeh Sima 
Published: May 2015

AbstractThis work presents a sol‐gel based biosensor for atrazine determination which has been obtained by introducing the enzyme polyphenol oxidase from apple tissue in a sol‐gel matrix. Apple tissue acts as a molecular recognition element. Atrazine is an inactive compound electrochemically; redox coupling of dopamine was used for studying atrazine behavior. Atrazine was determined by monitoring the inhibition power of polyphenol oxidase activity. The measurements were performed in 0.1 M KH2PO4‐NaOH buffer (pH 7.5). The effect of various experimental parameters such as pH, concentration of buffer, concentration of dopamine, incubation time and matrix composition has been investigated for optimum analytical performance. The biosensor consisted of 10.3% (w/w) of apple tissue. The bioelectrode exhibits a linear response for dopamine and atrazine concentrations in the range of 5.66 × 10−6−2.27 × 10−3M and 1 × 10−5 −1 × 10−4 M with a detection limit of 4.2 × 10−6 and 5.5 × 10−6 M, respectively. A correlation coefficient of 0.9945 and a relative standard deviation (R.S.D.) of 3.29% for dopamine, 0.9944 and 3.69% for a trazine were achieved.
Theoretical Description of the Geometry, Electronic Structure and Reactivity Analysis for a Set of Tris‐Chelates with Application in Organic Light Emitting Diodes
Authors: Vivas‐Reyes Ricardo , Núñez‐Zarur Francisco , Padilla Angélica 
Published: May 2015

AbstractWe have computed and compared the geometries, the electronic properties and reactivity sites of a set of Alq3‐derivatives (5AP‐Mq3, M=Al, Ga, In) with potential use in organic light emitting diodes (OLED), using electronic and chemical reactivity descriptors. All the geometries were optimized with the ab initio Hartree‐Fock (HF) method and the 3‐21G basis set and the different descriptors were calculated at a B3LYP/3‐21G level of theory. The results show that the geometric structures were all distorted octahedral, where the geometrical parameters increase in the order 5AP‐Alq3 < 5AP‐Gaq3 < 5AP‐Inq3. The frontier molecular orbitals HOMO and LUMO are split in energy and strongly localized in a specific region of the ligands. The reactivity analysis shows that the atoms that receive electrons are those associated with the lowest unoccupied molecular orbital, LUMO.
The Transition State of Free Radical SH2′ Reaction of Allyl Chloride with Organomercurial Study by Inverse Secondary α‐Deuterium Kinetic Isotope Effect
Authors: Wu Yuh‐Wern , Chen Ming‐Dar , Yang Jyh‐Ferng 
Published: May 2015

AbstractThe concerted mechanism of free radical SH2′ reaction of 2‐substituted allyl chloride was suggested again by inverse secondary α‐deuterium isotope effect. The transition state of free radical SH2′ reaction of allyl chlorides seems to be symmetrical and is not as early as that of a free radical addition reaction.
N,N,N′,N′‐Tetrabromobenzene‐1,3‐Disulfonamide and Poly(N‐Bromo‐N‐Ethyl‐Benzene‐1,3‐Disulfonamide) as Efficient Catalysts for the Methoxymethylation of Alcohols under Solvent‐Free Conditions
Authors: Ghorbani‐Vaghei Ramin , Zolfigol Mohammad Ali , Amiri Mostafa , Veisi Hojat 
Published: May 2015

AbstractMethoxymethylation of a variety of alcohols was performed using formaldehyde dimethyl acetal in the presence of N,N,N′,N′‐tetrabromobenzene‐1,3‐disulfonamide [TBBDA] and poly(N‐bromo‐N‐ethylbenzene‐1,3‐disulfonamide) [PBBS] as catalysts at room temperature and solvent‐free conditions. The methoxymethyl ethers (MOM‐ethers) were obtained with good to excellent yields.
Selective and Convenient Protection of Aldehydes as Azines under Solvent‐Free Conditions
Authors: Eshghi Hossein , Hosseini Mosayyeb 
Published: May 2015

AbstractAldehydes can be easily protected as azines in the presence of hydrazine monohydrochloride and ferric chloride under solvent‐free conditions. The major advantages of this method are: operational simplicity, ready availability, selectivity, general applicability, mild reaction conditions with low cost of the reactants, short reaction times and excellent yields.
A Novel and Efficient Catalyst to One‐Pot Synthesis of 2‐Amino‐4H‐Chromenes by Methanesulfonic Acid
Authors: Heravi Majid M. , Baghernejad Bita , Oskooie Hossein A. 
Published: May 2015

AbstractMethanesulfonic acid efficiently catalyzes the one‐pot, three component reaction of an aromatic aldehyde, malonitrile and α or β‐naphthol to yield 2‐amino‐4H‐chromenes in very good yields.
Synthesis of Deuterium Labeled Standards of 1‐Benzylpiperazine, Fenetylline, Nicocodeine and Nicomorphine
Authors: You Zong‐Yi , Chen Yi‐Jing , Wang Yu‐Yun , Chen Chinpiao 
Published: May 2015

AbstractIncreasingly abused, 1‐benzylpiperazine (BZP), fenetylline, nicocodeine and nicomorphine are central nervous system stimulants with neurotoxic properties. In recent years, many controlled substance analogs (designer drugs) with a large variety of structures have reached illegal markets, making their identification difficult. This work studies the synthesis of BZP‐d7, fenetylline‐d4, nicocodeine‐d4 and nicomorphine‐d8, as internal standards for use in gas chromatography‐mass spectrometry (GC‐MS) analysis for identification of these controlled substances.
Microwave Absorption and Infrared Stealth Characteristics of Bamboo Charcoal/Silver Composites Prepared by Chemical Reduction Method
Authors: Ting Tzu‐Hao , Wu Kuo‐Hui , Hsu Jen‐Sung , Chuang Ming‐Ho , Yang Cheng‐Chien 
Published: May 2015

AbstractBamboo charcoal coated with silver (BC/Ag) was prepared by activation and chemical reduction processes at different AgNO3 contents (10‐30 wt.%). The spectroscopic characterizations of the formation processes of BC/Ag composites were studied using X‐ray diffraction, scanning electron microscopy and transmission electron microscopy. These composites were introduced in epoxy resin to be a microwave absorber and mixed polyethylene to be an infrared stealth plate. Microwave absorbing properties were investigated by measuring complex permittivity, complex permeability and reflection loss in the 2‐18 and 18‐40 GHz microwave frequency range using the free space method. The thermal extinction measurements in the 3‐5 and 8‐12 μm were done to evaluate the shielding affectivity of infrared. The results showed that a significant thermal extinction and a wider absorption frequency range could be obtained by adding silver to bamboo charcoal.
Determination of Nitrophenols in Water Using Dynamic Liquid‐Liquid‐Liquid Microextraction under Non‐Equilibrium Consideration
Authors: Lin Che‐Yi , Huang Shang‐Da 
Published: May 2015

AbstractTo pursue optimum condition in liquid‐liquid‐liquid microextraction (LLLME), extraction parameters dominating extraction efficiency were investigated by theoretical considerations. The theoretical considerations discussed equilibrium model for equilibrium LLLME and non‐equilibrium model for dynamic LLLME. A method described here is a dynamic LLLME technique combined with high‐performance liquid‐chromatography ultraviolet absorbance detection (HPLC/UV) to determine traces of nitrophenols in water. Analytical parameters such as organic phase, acceptor phase volume, sample agitation, extraction time, acceptor phase NaOH concentration, donor phase HCl concentration, salt addition, and absorption wavelength were identified as variable settings. Relative standard deviation (RSD, 1.8‐4.4%), coefficient of estimation (R2, 0.9994‐0.9999), and detection limit (0.032‐0.065 ng mL−1) were achieved under the variable settings. The proposed method was successfully applied to the analysis of a lake water sample, and the relative recoveries of nitrophenols from spiked water sample were up to 92.5%. The variable settings of LLLME close to optimization was responsible for an acceptable extraction efficiency.
Ionic Liquid as an Efficient Promoting Medium for Synthesis of Bis‐Pyrazolo[3,4‐b:4′,3′‐e]Pyridines
Authors: Shi Da‐Qing , Yang Fang 
Published: May 2015

AbstractThe preparation of a series of bis‐pyrazolo[3,4‐b:4′,3′‐e]pyridines by the reaction of 5‐aminopyrazole with aldehydes in ionic liquid [bmim]Br is described. This new method has the advantages of easier work‐up, milder reaction conditions, high yields and environmental friendliness compared with other methods.
Amberlyst‐15‐Catalyzed Novel Synthesis of Quinoline Derivatives in Ionic Liquid
Authors: Hou Rei‐Sheu , Wu Jian‐Long , Cheng Hui‐Ting , Xie You‐Teng , Chen Ling‐Ching 
Published: May 2015

AbstractIn recent years, ionic liquids have attracted much attention as useful synthetic solvents. Compared with classical molecular solvents, the ionic liquids are environmentally benign reaction media. A variety of quinoline derivatives have been synthesized under ionic liquid conditions using Amberlyst‐15 as catalyst.
Synthesis and Evaluation of the Cytotoxicities of Neoflavenes
Authors: Li Sie‐Rong , Chen Hsing‐Ming , Chen Po‐Yuan , Tsai Jui‐Chi , Chen Liang‐Yeu , Wang Eng‐Chi , Huang Yi‐Ting , Wei Yun‐Chen , Lu Pei‐Jung 
Published: May 2015

AbstractThe synthesis of neoflavene and neoflavenes with methoxy substituents at different positions are described. As starting materials, various salicylaldehydes were run through sequential reactions such as O‐allylation, Grignard reaction, oxidation, Wittig reaction, and ring‐closing metathesis to yield the target neoflavenes in good yield. Among the prepared neoflavenes, 7‐methoxy‐4′‐methoxyneoflavene (6e) and 8‐methoxy‐4′‐methoxyneoflavene (6f) exhibiting potential cell toxicities against various cells were disclosed. In particular, 6f which exhibited an IC50 value of 6.5 ± 2.0 and 5.1 ± 1.1 μM against gastric carcinoma and lung carcinoma cells in vitro was found, respectively. Meanwhile, the structure and activity relationship of our synthesized neoflavenes is further discussed briefly.
Vanadium Hydrogen Sulfate (I): Chemoselective Trimethylsilylation of Alcohols and Deprotection of Trimethylsilyl Ethers
Authors: Shirini Farhad , Zolfigol Mohammad Ali , Abedini Masoumeh , Sakhaei Ali Reza 
Published: May 2015

AbstractTrimethylsilylation of alcohols with hexamethyldisilazane (HMDS) catalyzed by V(HSO4)3 under mild and completely heterogeneous reaction condition is reported. The method is highly chemoselective for the protection of alcohols in the presence of phenols, amines and thiols. Also, the deprotection of trimethylsilyl ethers is performed in the presence of V(HSO4)3 at room temperature in good to high yields.
Derivative and Derivative Ratio Spectrophotometric Analysis of Antihypertensive Ternary Mixture of Amiloride Hydrochloride, Hydrochlorothiazide and Timolol Maleate
Authors: Abdel‐Hay Mohamed H. , Gazy Azza A. , Hassan Ekram M. , Belal Tarek S. 
Published: May 2015

AbstractTwo simple, rapid and reliable spectrophotometric methods are described for the resolution of the three‐component mixture of amiloride hydrochloride (AMD), hydrochlorothiazide (HCT) and timolol maleate (TIM). The first method involves the use of derivative spectrophotometry with the zero‐crossing technique where AMD was easily determined using its 0D and 1D(Δλ = 6) amplitudes at 365 and 385 nm, respectively, while HCT and TIM were determined by measuring the 3D(Δλ = 6) amplitude at 265 nm and the 1D(Δλ = 8) amplitude at 315.4 nm, respectively. The second method involves the application of the ratio‐spectra zero‐crossing first and second derivative spectrophotometry where two points have been used for the quantification of each compound. For the determination of AMD, HCT was used as divisor and the 1DD (Δλ = 4) and 2DD (Δλ = 6) values at 299.4 and 311 nm, respectively, were plotted against AMD concentration; while — by using TIM as divisor — the 2DD (Δλ = 6) amplitudes at 264.2 and 290 nm were found to be proportional to HCT concentration. TIM was assayed in the mixture using its 1DD (Δλ = 6) amplitudes at 289.8 nm (Divisor was AMD) and 314.8 nm (Divisor was HCT). Synthetic mixtures of different proportions and laboratory‐made tablets were assayed by the proposed methods and the results revealed good accuracy and repeatability of the developed methods.