Utility of p-chloranilic Acid and 2,3 Dichloro-5,6-dicyano p-Benzoquinone (DDQ) for the Spectrophotometric Determination of Triamterene

Abstract

Two simple and sensitive spectrophotometric procedures are suggested for analysis of triamterene. The first procedure is based on the reaction of triamterene with p-chloranilic acid (p-CA) in methylene chloride to form a highly stable coloured product, exhibiting maximum absorbance at λ 530 nm. Beer's law is obeyed in the range of 40–220 μg.ml^?1 with a mean percentage accuracy of 99.98 ± 0.446. Limit of determination is 20 μg.ml^?1. In the second procedure, the drug is determined via charge transfer complex formation with 2,3 dichloro-5,6-dicyano p-benzoquinone (DDQ) using methylene chloride as a solvent. Here the reaction product has two well defined maxima at 460 nm and 530 nm where each has been utilized for quantitative determination. Beer's law is obeyed in concentration ranges of 25–125 μg.ml^?1 and 25–150 μg.ml^?1 with mean percentage accuracies of 99.92 ± 0.449 and 100.00 ± 0.511 for both maxima. 460 and 530 nm. respectively. Limit of determination is 12.5 μg.ml^?1 at both maxima. Optimum conditions for each procedure have been studied and the stoichiometry of both reactions was ascertained using Job's method of continuous variation. The validity of the suggested procedures was assessed by applying the standard addition technique using the drug capsules. Both procedures are statistically analyzed as compared with BP method for analysis of triamterene (non aqueous titration) revealing good accuracy and precision as indicated by t and F tests.     

Spectrophotometric Determination of Diphenadione Via its Metal Complexes

Abstract

Spectrophotometric procedure is described for the quantitative determination of diphenadione [2-(diphenylacetyl)-1,3-indandione], based on direct spectrophotometric measurements of the absorbances of its iron (III), iron (II) and cobalt (II), metal complexes at 488 nm, 505 nm and (334 nm, 372 nm), respectively. The drug reacts with metals in the ratio of 3:1 and 2:1 for iron (III) and for both iron (II) and cobalt (II) respectively. The obtained complexes have apparent molar absorptivities of 1.48 × 10³ 1 mol^?1 cm^?1, 0.714 × 10³ 1 mol^?1cm^?1 and (1.70 × 10³ 1 mol^?1cm^?1, 1.93 × 10³ 1 mol^?1cm^?1) for iron (III), iron (II) and cobalt (II) complexes, respectively. The procedure is suggested for the determination of 51–400 μg.ml^?1 diphenadione via the iron (II) complex and 35–170 μg.ml^?1 diphenadione via both cobalt (II) and iron (III) complexes. The suggested procedure has accuracies of 99.79 ± 0.67%, 99.64 ± 0.37% and (100.09 ± 0.53%, 99.99 ± 0.42%) for the metal complexes of iron (III), iron (II) and cobalt (II), respectively.     

Innovative Spectrophotometric Methods for Determination of Almitrine Dismesylate and Raubasine in Duxil Tablets

Abstract

Ratio subtraction and isosbestic point are two methods used to determine a mixture of almitrine dismesylate and raubasine. Linear correlations were obtained in the range from 4 to 18 µg ml^?1 for almitrine dismesylate and 2 to 16 µg ml^?1 for raubasine, with mean accuracies 99.87 ± 1.053 for almitrine dismesylate and 99.75 ± 1.301 for raubasine. Almitrine dismesylate and raubasine (II) in their mixtures were analyzed by the two methods where the total content was determined at the isosbestic point at 214.0 nm and raubasine was determined by ratio subtraction. The proposed methods were validated to be suitable for analysis of the pharmaceuticals.     

Simultaneous Determination of Dipyrone and Papaverine in Pharmaceutical Formulation using PLS Regression and UV Spectrophotometry

Abstract

A combination of sodium dipyrone and papaverine hydrochloride is used as an analgesic and antispasmodic drug. A simple and rapid procedure is proposed for simultaneous determination of these drugs in commercial formulations (Melpaz^®) based on partial least squares (PLS) regression and UV spectrophotometric measurements in the range of 218–300 nm. The calibration set was built with 25 solutions in concentrations ranging from 15.0–35.0 mg ml^?1 for dipyrone and from 0.5–1.5 mg ml^?1 for papaverine in methanol. The relative standard deviation (RSD) was 1.05% for dipyrone and 1.55% for papaverine in pharmaceutical formulations. The percent of relative recovery was 95.9% for dipyrone and 95.2% for papaverine. Figures of merit, such as accuracy, precision, sensitivity and adjust were also determined. The methodology was validated by using an independent method, based on high performance liquid chromatography (HPLC).     

Spectrophotometric determination of metronidazole in pharmaceutical pure and dosage forms using p-benzoquinone

A simple and accurate spectrophotometric method for the determination of metronidazole in pure and pharmaceutical dosage forms has been developed. The proposed method is based on the reduction of the nitro group to amino group of the drug. This can be achieved by heating a mixture of an alcoholic solution of metronidazole, zinc powder and dilute hydrochloric acid in a water bath at 90 ± 5 °C for 15 min. The cold and clear filtrate reacts with p-benzoquinone to develop a purple color, which absorbs maximally at 526 nm. The calibration graph is linear over the concentration range of 15–190 μg ml^?1 with a molar absorptivity of 1.09 × 10³ l mol^?1 cm^?1. The proposed method is applied to commercially available pharmaceutical dosage forms and the results are statistically compared with those obtained by the reference method.     

Spectrophotometric Assay of Certain Aminoglycosides Using Cyanoacetamide

Abstract

A simple and sensitive ultraviolet spectrophotometric method has been devised for the determination of amikacin, kanamycin, neomycin and streptomycin in pure form and in some pharmaceutical preparations. The method depends on the nitrosation of the primary amino groups followed by reaction with cyanoacetamide in ammonia medium at 100°C for 30 min, The reaction products exhibit a characteristic absorption. maximum at 270 nm. Beer's law is obeyed within the concentration ranges 4–40 μg ml^?1 for amikacin, kanamycin and neomycin and 8–80 μg ml^?1 for streptomycin with apparent molar absorptivities of about 1.85 × 10⁴ for the first three compounds and 1.3×10⁴ 1. mole^?1.cm^?1 for streptomycin.     

Spectrophotometric Determination of Acebutolol Hydrochloride and Nicoumalone with Metol and Potassium Permanganate

Abstract

A spectrophotometric method is described for the determination of Nicoumalone and Acebutolol hydrochloride based on the formation of molecular complex with the reduction product of Nicoumalone or hydrolysis product of Acebutolol hydrochloride and p-N-methyl benzoguinone monoimine [formed in situ from met01 (p-N-methylaminophenol sulfate) and potassium permanganate, PMBQMI] at pH 3.3. Quantitative measurements were made at the maximum absorption of 525 nm. Beer's law is obeyed in the range of 5–50 μg ml^?1 and 5–60 μg ml^?1 for Nicoumalone and Acebutolol hydrochloride respectively. The proposed method is comparable with the reference method when applied to pharmaceutical preparations, and tablets, An average percentage recovery of 99.5 ± 0.8 was obtained.     

Spectrophotometric Determination of Ampicillin with Some Nitro Compounds

Abstract

A spectrophotometric procedure for the determination of ampicillin (Amp.) in pure solutions and in its pharmaceutical preparations has been developed. This new method offers advantages of simplicity, rapidity and stability in comparison with the official BP (1980) method. The proposed method is based on the formation of a colour condensation product through the reaction of ampicillin and nitrobenzene derivatives in an alkaline aqueous-acetone medium 40% (v/v). Beer's law is obeyed in the range 0.5–28 μg ml^?1. The colours were produced within 20 min. after heating at 60±5°C and stable for at least 6 h. The method is relatively accurate (recovery 100±2%) and precise (RSD 1.9%) and can be used successfully for the preparation of capsules, syrup and ampoules.     

Spectrophotometric Studies on the Proton Transfer from the Protonated DNA to 5,10,15,20-Tetrakis[4-(trimethyammonio)-phenyl]porphine

Abstract

The interaction of nucleic acids with 5, 10, 15, 20-tetrakis[4-trimethy-ammonio)phenyl]porpine (TAPP) were investigated on the basis of a mechanistic discussion, and a spectrophotometric method for DNAs was accordingly proposed in the present paper. Depending on the acidity of the solution, TAPP can interact with nucleic acids, producing different absorption features. When the pH of the solution is higher than 6.39, TAPP can interact with both DNAs and RNA, giving a new absorption band at 420.3 nm. If the pH is lower than 6.39, however, the interactions with DNAs (but not RNA) can give an absorption band centered at 436.3 nm. It was found that the absorption band at 436.3 nm originates from the proton transfer from the protonated double-stranded structure of DNA to TAPP. At optimal conditions, the absorbance at 436.3 nm is in proportion to the concentration of the DNAs. Calibration curves were linear in the range of 0±3.0 μg.ml^?1 for calf thymus and 0±3.2 μg.ml^?1 for fish sperm DNA. No interference of 4-fold of RNA was found for the determination of DNAs. The limits of determination (3[sgrave]) were 34.6 ng.ml^?1 for calf thymus DNA and 33.2 ng.ml^?1 for fish sperm DNA, respectively. Four synthetic samples were determined with satisfaction.     

Stability-Indicating Method For The Determination Of N-Desmethyldiazepam And Simultaneous Determination Of Its Degradation Products

Abstract

A simple, direct and sensitive spectrophotometric method for the determination of the intact N-desmethyldiazepam in the presence of its degradation products, 2-amino-5-chlorobenzophenone and glycine, is developed. The proposed procedure is based on direct measurement of the absorbance of its acidified methanolic solution at 361 nm. The procedure determines 8–56 mcg ml^?1 of N-desmethyldiazepam with an accuracy of 100.2 ± 0.51%. The proposed procedure retains its accuracy in presence of up to 80% of the different degradation products. The procedure is applied successfully for the determination of N-desmethyldiazepam in bulk powder, tablets and drops.

Simultaneous determination of the different degradation products in the presence of the parent drug is also described. Thus, 2-amino-5-chlorobenzophenone is determined by direct measurement of its methanolic solution at about 380 nm, with an accuracy of 100.4 ± 0.42%. Glycine is determined colorimetrically using ninhydrin reagent in presence of pyridine, with an accuracy of 99.5 ± 0.78%.     

Difference spectrophotemetric assay of mixtures of phenylpropanolamine hydrochloride with guaifensesin or fextromethorphan hydrobromide in olid cough formulations

A difference spectrophotometric method is described for the selective assay of phenylpropanolamine hydrochloride(I) in the presence of guaifenesin(II) or dextromethorphan hydrobromide(III) without prior separation. The method is based on the spectral change upon oxidation of phenylpropanolamine to benzaldehyde by sodium metaperiodate. The difference absorption spectrum is obtained by measuring oxidized against unoxidized phenylpropanolamine. This spectrum exhibits a maximum of 251.5 nm, a minimum at 275 nm and an isosbestic point at 272.5 nm. Absorbance is linear with concentration for 25–100 μg ml^?1 phenylpropanolamine at 251.5 nm. No changes in the spectra of compounds II and III were observed when these compounds were treated with metaperiodate. Guaifenesin and dextromethorphan are assayed by measuring an aliquot of the sample solution against methanol at 281.5 nm and 286 nm, respectively. Phenylpropanolamine does not interfere at these wavelengths. Calibrations are linear over the range 25–125 μg ml^?1 for II and III. Overall recoveries (±SD, n = 5) from simulated tablets were 99.8 ± 2.6% for I and 100.5 ± 0.5% for II; from simulated capsules, the recoveries were 99.2 ± 0.4% for I and 99.6 ± 0.2% for III. The assay was succesfully applied to commercial tablets and capsules containing these compounds.     

Spectrophotometric Analysis of some Phenothiazine Neuroleptics using Chloramine-T

ABSTRACT

A sensitive and selective spectrophotometric method has been developed for the determination of six phenothiazine neuroleptics. The method is based on the interaction of the drugs with chloramine-T in sulphuric acid medium to yield a red, reddish-violet, orange or greenish-blue intermediate with maximum absorption at 500-636 nm. Beer's law is obeyed over the range 5-125 μg ml^?1 of the drugs. The apparent molar absorptivities were found to be in the range 1.04x10³ to 5.46x10³ 1.mol^?1cm^?1. The investigated drugs were assayed in tablets and injections. The mean percentage recoveries were 97.65-101.75 and the relative standard deviations were found to be less than 2%.     

Spectrophotometric and Spectrofluorimetric Determination of Famotidine and Ranitidine Using 1,4-Benzoquinone Reagent

ABSTRACT

Spectrophotometric and spectrofluorimetric methods were adopted for the analysis of Famotidine and Ranitidine depending on their reaction with 1,4 Benzoquinone reagent at pH 5.2 and 5.6, respectively. The absorbances of the resulting condensation products were measured at 502 and 508 nm for Famotidine and Ranitidine, respectively. Concentrations adhering to Beer's law were from 40-160 μg.ml^? for Famotidine and from 20-100 μg.ml^? for Ranitidine.

Furthermore the resulting condensation products exhibited fluorescence at 665 nm when excited at 290 nm and the calibration graphs were rectilinear from 0.4-1.4 μg.ml^? for Famotidine and from 0.21 μg.ml^? for Ranitidine.

Different parameters affecting these reactions were thoroughly studied. Also these methods were applied to the pharmaceutical preparations and the results were satisfactory. The validities of the methods were ascertained by the standard addition technique revealing fine results in consideration to the mean recovery percent and standard deviation.

The spectrofluorimetric method was a hundred times more sensitive then the spectrophotometric method. The proposed methods were sensitive, accurate, and precise as statistically compared with the official methods of analysis of Famotidine and Ranitidine.     

Liquid-Liquid Extraction,Photometric and Atomic Absorption Spectrophotometric Determination of Mercury

Abstract

A selective and sensitive spectrophotometric and atomic absorption spectrophotometric method is developed for the determination of traces of mercury with N-phenylcinnamohydroxamic acid (PCHA) in the environment. Mercury is extracted into a chloroform solution of PCHA at pH 8.5-10.0 and determined by AAS. The mercury hydroxamate binary complex is yellow in colour having a maximum absorbance at 390 nm and molar absorptivity 4.3 × 10³ 1 mol^?1 cm^?1, sandell sensitivity 0.0466 μg/cm². The ternary system using 1-(2-pyridylazo)-2-naphthol has molar absorptivity 8.82 × 10³ 1 mol^?1 cm^?1 at 550nm, sandell sensitivity 0.0228 μ/cm². Beer's law is obeyed in the concentration range of 2.37-38.0 ppm and 0.80-19.5 ppm of mercury for binary and ternary system, respectively. The extraction of Hg-PCHA binary system is studied with a liquid cation exchanger, bis-(2-ethyl hexyl) phosphoric acid (HDEHP) and found to have better selectivity than Hg-PCHA-PAN system. The molar absorptivity of the Hg-PCHA-HDEHP system is 8.82 × 10³ 1 mol^?1 cm^?1 at 390 nm and Beer's law is obeyed in the concentration range of 0.47-20 ppm of mercury.

The present method is applied to the determination of mercury in eye drops, aurvedic drugs and environmental samples.     

A New Spectrophotometric Method for the Determination of Arsenic in Environmental and Biological Samples

Abstract

A simple and selective spectrophotometric method has been developed for the determination of trace amounts of arsenic using azure B as a chromogenic reagent. The proposed method is based on the reaction of arsenic(III) with potassium iodate in acid medium to liberate iodine. The liberated iodine bleaches the violet color of azure B and is measured at 644 nm. This decrease in absorbance is directly proportional to the As(III) concentration, and Beer's law is obeyed in the range 0.2–10 µg ml^?1 of As(III). The molar absorptivity, Sandell's sensitivity, detection limit, and quantitation limit of the method were found to be 1.12×10⁴ l mol^?1cm^?1, 6.71×10^?3 µg cm^?2, 0.02 µg ml^?1 and 0.08 µg ml^?1, respectively. The optimum reaction conditions and other analytical parameters were evaluated. The proposed method has been successfully applied for the determination of arsenic in various environmental and biological samples.     

2-(2-Thiazolylazo)-p-cresol(TAC) as a Reagent for the Spectrophotometric Determination of Lead(II)

Abstract

The reaction between lead(II) and 2-(2-Thiazolylazo)-p-Cresol(TAC) in the presence of TERGITOL NPX (4 mg/ml) at an apparent pH 9.0–10.0 results in an intensely colored complex which is stable for at least 4 hr.

The composition of the complex is 1:2 cation: TAC and the log of the formation constant is 11.92 ± 0. 40. Beer's law is obeyed up to 6.0μg.ml^?1 of lead(II) at 650nm.

The apparent molar absorptivity at 650 nm is 2.07 × 10⁴ 1. mole^?1.cm^?1 and the detection limit was obtained as 10.0 ng.ml^?1 of lead(II).

The method is applied to determination of lead(II) in copper-base alloy.     

A Comparative Study on Spectrophotometric,Conductometric and Potentiometric Determination of Ascorbic Acid

Abstract

A comparison has been made on the selectivity, accuracy and precision of spectrophotometric, conductometric and potentiometric methods for the determination of ascorbic acid in water which is based on the reduction of gold(III) ion by ascorbic acid. Gold(III) ion forms a complex with gelatin in alkaline medium which on reduction with ascorbic acid produces coloured gold sol. The sol shows an absorption maximum at 540 nm with molar absorptivity of 2.3×10^?3litre mol^?1 cm^?1 and the Sandell's sensitivity of 7.6 × 10^?2 μgcm^?2. The relative standard deviation is 0.22% and the confidence limit (20 determinations, 95%) is 2.0 ± 0.009%. To examine the extent of sensitivity of the spectrophotometric method the proposed method is compared with the sensitivities of the conductometric and potentiometric methods.     

Abilities of Partial Least‐Squares (PLS‐2) Multivariate Calibration in the Analysis of Quaternary Mixture of Food Colors (E‐110, E‐122, E‐124, E‐131)

Abstract

Sunset Yellow (SY), Carmoisine (C), Ponceau 4R (P), and Patent Blue V (PB) are synthetic organic dyes which are under governmental regulations all over the world because of their toxicity and carcinogenicity.

In this study, a simple and fast analytical procedure was proposed for the simultaneous determination of food dyes (SY, C, P, and PB) in powder drinks by means the partial least‐square treatment of spectrophotometric absorbance between 450 –730 nm, taken at 10 nm intervals. The experimental calibration matrix was constructed with 27 samples. The concentration ranges considered were 2, 3, 4 µg · ml^?1 for SY, 7, 8, 9 µg · ml^?1 for C, 9, 10, 11 µg · ml^?1 for P, and 0.3, 0.4, 0.5 µg · ml^?1 for PB. The method was applied to the determination of dyes in different commercially available powder drinks. The results obtained by the application of the PLS‐2 method were statistically compared with those obtained by an HPLC method using the F and t tests. Very similar values were found by two methods. No time consuming pretreatment was needed and this method also provides rapid, accurate and economical analysis of these colors.     

Flow-Injection Analysis Based on Extraction and Spectrophotometric Determination of Penicillins with Thiazine Dyes

Abstract

A new method for flow-injection analysis (FIA) for the determination of penicillins based on the extraction and spectrophotometric determination of ion associates with selected thiazine dyes (methylene blue, azure A, and azure B) is proposed. The reaction conditions (c_dye = 2 × 10^?4 mol l^?1, c_KCl = 1 mol l^?1, pH ? 6, λ = 635 nm) were found. The factorial design has been carried out to determine the optimum flow conditions. A wide linear dynamic range of calibration curves (5.1–700 µg ml^?1 for penicillin V with all dyes, R = 0.9985) and good repeatability (e.g., relative standard deviation [RSD] = 4.6–0.6% in this concentration range for the reaction with azure B) were found. The detection limit for penicillin V is 1.5 µg ml^?1, and the determination limit is 5.1 µg ml^?1. The maximum analysis rate is 35 samples per h. The practical samples of pharmaceutics were tested. There are no interferences from the additives in pharmaceutics.     

Novel Method for Selective Spectrophotometric Determination of Titanium(IV) with Water Extract of Slippery Elm Leaf as a New Reagent

Abstract

A novel spectrophotometric method for the determination of titanium(IV) by using a new reagent, water extract of slippery elm leaf is developed. In 0.05 M hydrochloric acid, titanium(IV) reacts with this reagent to form a yellow product. The formed product shows maximum absorbance at 415 nm with a molar absorptivity value of 0.68×10⁴ l mol^–1 cm^–1 and the method was linear in the 0.2–6 µg ml^?1 concentration range. The detection limit value was found to be 0.0131 µg ml^?1. The proposed method was simple, low cost, selective, and sensitive. It was applied to the analytic samples with satisfactory results.