Extractive Spectrophotometric Method For Determination Research Articles

Development of Method for Extractive Spectrophotometric Determination of Cu(II) with 2-Hydroxy-1-Naphthalene Carboxaldehyde Phenyl Hydrazone as an Analytical Reagent

A spectrophotometric method has been developed for the determination of Cu(II) using 2-Hydroxy-1-Naphthalene carboxaldehyde phenyl hydrazone as an extractive reagent. The reagent forms a coloured complex, which has been quantitatively extracted into n-butanol at pH 9.2. The method obeys Beer’s law over arrange from 1 to 10 ppm. The Molar absorptivity and Sandell’s sensitivity were 0.97 × 104 L mol-1cm-1 and 0.26 µg·cm-2 respectively. The proposed method is very sensitive and selective. The method has been successfully applied to synthetic and commercial samples.

A New extractive spectrophotometric method for determination of rizatriptan dosage forms using bromocresol green

Background and the purpose of the studyRizatriptan is used effectively for the treatment of migraine headache. In this study, a simple, rapid and low cost spectrophotometric method based on the ion-pair complexation is proposed for the determination of rizatriptan in raw material and dosage forms.MethodsThe ion-pair complexation using bromocresol green as reagent was performed in a buffer solution and the absorbance was measured by a spectrophotometer. The ion-pair formation conditions were optimized and the accuracy and precision of the method were calculated.Results and major conclusionBest results were achieved by using 6 ml of the bromocresol green reagent in the presence of phosphate buffer (pH 3.0). The stoichiometry of the resulted complex was 1:1. The within-day and between-day precision values were lower than 2.9 and 1.8 percent for the calibration range of 0.5–50 and 10–100 μg/ml, respectively. The proposed method was successfully used for the determination of rizatriptan in dosage forms without any interference.

Development of a reliable analytical method for extraction spectrophotometric determination of ruthenium(III) from catalyst and fissium alloy using o-methylphenyl thiourea as a chromogenic chelating ligand

A simple and selective method is developed for the extraction spectrophotometric determination of ruthenium(III) using o-methylphenyl thiourea (OMPT) as a chromogenic chelating ligand. The basis of the proposed method is ruthenium(III)–OMPT complex formation in aqueous hydrochloric acid media (3.0molL−1) after 5.0min heating on a boiling water bath and the complex formed is extracted into chloroform. The absorbance of green colored ruthenium(III)–OMPT complex is measured at 590nm against the reagent blank. Beer’s law was obeyed up to 42.5μgmL−1 of ruthenium(III) and the optimum concentration range is 7.56–39.81μgmL−1 of ruthenium(III) as evaluated by Ringbom’s plot. Molar absorptivity and Sandell’s sensitivity of ruthenium(III)–OMPT complex in chloroform are 2.34×103Lmol−1 cm−1 and 0.043μgcm−2 respectively. The composition of ruthenium(III):OMPT complex (1:2) was established from slope ratio method, mole ratio method and Job’s continuous variation method. Complex was stable for more than 48h. The interfering effect of various foreign ions was studied and suitable masking agents are used wherever necessary to enhance the selectivity of the method. Proposed method is successfully applied for determination of ruthenium(III) from binary and ternary synthetic mixtures, synthetic mixtures corresponding to fissium alloy and ruthenium catalyst. Repetition of the method was checked by finding relative standard deviation (R.S.D) for 10 determinations which was 0.23%. A scheme for sequential separation of palladium(II), ruthenium(III), rhodium(III) and platinum(IV) has been developed.

Spectrophotometric analysis of trichloroethylene in various environmental and biological samples

A simple sensitive extractive spectrophotometric method for determination of trichloroethylene is proposed. Trichloroethylene is treated with pyridine to form glutaconic aldehyde by heterolytic cleavage of the pyridine ring. Glutaconic aldehyde is further coupled with 4-aminoacetanilide to form an orange–red dye which is extractable in 3-methyl-1-butanol. The extracted dye shows absorption maximum at 520 nm. The system obeys Beer’s law in the range of 0.05–0.8 μg mL−1. Important analytical parameters such as time, temperature, reagent concentration, acidity etc. have been optimized for complete colour reaction. Sandell’s sensitivity and molar absorptivity for the system were found to be 0.001 μg cm−2 and 1.2 × 105 L mol−1 cm−1, respectively. The proposed method is satisfactorily applied to micro-level determination of trichloroethylene in various environmental and biological samples.

Extractive Spectrophotometric Method for Determination of Molybdenum in Steels and Environmental Samples

An extractive spectrophotometric method has been developed for microdetermination of molybdenum. At room temperature Mo(VI) was reduced to Mo(V) in 2 M H2SO4 using ascorbic acid as a reductant. The Mo(V) formed a yellow‐coloured (1 : 2) complex with 6‐chloro‐3‐hydroxy‐2‐(3′‐hydroxyphenyl)‐4‐oxo‐4H‐1‐benzopyran (CHHB). The complex was quantitatively extracted into toluene and absorbed maximum at λmax 404 nm. Beer’s law was obeyed over the concentration range of 2.31 μg Mo ml−1 with a molar absorptivity and Sandell′s sensitivity of 5.62 × 104 L mol−1 cm−1 and 0.0016 μg Mo cm−2, respectively. The relative standard deviation was 0.0025 (in absorbance units) for 10 replicate determinations of 1 μg Mo ml−1. The method was free from the interference of large number of analytically important elements. Molybdenum has been determined satisfactorily in different technical, synthetic, and environmental samples with improved accuracy and precision.

Extractive Spectrophotometric Method for Determination of Pioglitazone Hydrochloride in Raw Material and Tablets Using Ion‐Pair Formation

A simple, rapid and extractive spectrophotometric method was developed for the determination of pioglitazone hydrochloride in pure and pharmaceutical formulations. This method is based on the formation of yellow ion‐pair complex between the basic nitrogen of the drug and bromocresol green (BCG) in phthalate buffer of pH 2.4. The formed complexes were extracted with chloroform and measured at 419 nm. The analytical parameters and their effects on the proposed systems are investigated. Beer’s law was obeyed in the range 2.5‐14 μg/mL with correlation coefficient ≥ 0.995. The proposed method has been applied successfully for the determination of drug in commercial tablets dosage forms. No significant interference was observed from the excipients commonly used as pharmaceutical aids with the assay procedure. The validity of the proposed method was established by parallel determination against HPLC method and there was no significant difference between these two methods.

Development of a highly sensitive and selective method for extractive spectrophotometric determination of aluminum(III) from environmental matrices, synthetic mixtures, and alloys using orthohydroxypropiophenoneisonicotinoylhydrazone

Orthohydroxypropiophenoneisonicotinoylhydrazone (OHPINH) is proposed as a new sensitive reagent for the spectrophotometric determination of aluminum(III). OHPINH formed a greenish-yellow colored complex with aluminum(III) in buffer solutions of pH 1 to 3. The color in pH 2 was stable for more than 48 h. The complex solution has given maximum absorbance at 390 nm when the reagent was chosen as blank and the absorbance of the reagent at this wavelength is negligible; the molar absorptivity and Sandell's sensitivity being 0.6371x10(4) L mol(-1) cm(-1) and 4.234x10(-3) microg cm(-2), respectively. The system obeys Beer's law in the range of 0.5-3.5 microg mL(-1) with excellent linearity in terms of the correlation coefficient value of 0.999. Most of the common metal ions generally found associated with aluminum(III) do not interfere. The repeatability of the method was checked by finding the relative standard deviation. The developed method has been successfully employed for the determination of aluminum(III) environmental matrices like medicinal and leafy samples, alloys, and synthetic mixtures.

Extractive Spectrophotometric Methods for Determination of Clarithromycin in Pharmaceutical Formulations Using Bromothymol Blue and Cresol Red

AbstractTwo simple and sensitive extractive spectrophotometric methods have been described for the analysis of clarithromycin in pure form and in pharmaceutical formulations. The methods involved formation of yellow colored chloroform extractable ion‐association complexes of clarithromycin with bromothymol blue (BTB) and cresol red (CR) in buffered aqueous solution at pH 4. The extracted complexes showed maximum absorbance at 410 and 415 nm for BTB and CR, respectively. Beer's law is obeyed in the concentration ranges 0.1–20 μg mL−1 and 2.0–20 μg mL−1 of clarithromycin with molar absorptivity of 2.01 × 104 and 4.378 × 103 for BTB and CR, respectively. The composition ratio of the ion‐association complex was clarithromycin: BTB and CR = 1:1 as established by Job's method. The methods have been applied to the determination of drug in commercial formulations. The results of analysis were validated statistically and through recovery studies.

Extractive spectrophotometric method for determination of metribuzin herbicide and application of factorial design in optimization of various factors

A simple extractive spectrophotometric method has been described for the determination of metribuzin herbicide. Metribuzin was reacted with copper and a stable complex in the presence of ammonia (0.2 M) at pH 10.5 was formed. The resulting yellow coloured complex was extracted in chloroform and showed absorption maxima at 340 nm. Beer’s law was obeyed in the range of 0.8–25 μg mL −1 with molar absorptivity of 5.67 × 10 3 L mol −1 cm −1. The composition of the complex was studied by Job’s method of continuous variation and the results indicated that the mole ratio of metribuzin:Cu 2+ is 2:1. The optimum reaction conditions for complexation and other analytical parameters were evaluated. A two-level factorial design was also used to determine the effect of different parameters and their interaction on metribuzin:Cu 2+ complex formed. The method was successfully applied for the determination of metribuzin in commercial formulations and real samples.

Micelle mediated extraction of titanium and its ultra-trace determination in silicate rocks

A highly sensitive method for extractive spectrophotometric determination of titanium in silicate rocks is described. Titanium in the range 0–10 μg as TiO 2 is extracted into benzene or toluene by the formation of a ternary complex of the metal with thiocyanate (SCN −) and cetyltrimethylammonium bromide (CTA) in the ratio 1:2:2. A deep yellowish-orange ternary complex thus formed is suitable for the determination of titanium at wavelength 421 nm. The optimum colour intensity of this ternary complex was attained when the complex was extracted from an aqueous solution having concentrations of thiocyanate and HCl, in the range, 1.5–2.5 and 1–5 mol L −1, respectively. The molar absorptivity and Sandell's sensitivity of the extracted species were found to be 1.1–1.0 × 10 5 L mol −1 cm −1 and 0.47 ng cm −2 (referred to titanium), respectively, at λ max of 421 nm. Except Fe 3+, Nb 5+ and V 5+, no interference was encountered in the estimation of titanium. While up to 10 mg L −1 Nb and V did not interfere in the determination of titanium, the interference of Fe 3+ was eliminated by reducing it to Fe 2+ using SnCl 2 solution. The method is highly sensitive and selective. The results obtained for titanium estimation in a host of silicate rock samples have been found to be highly reproducible, accurate and favourably comparable with certified values of reference materials and those obtained from standard methods.

Extractive Spectrophotometric Methods for Determination of Zolmitriptan in Tablets

Two simple and sensitive extractive spectrophotometric methods have been developed for determination of zolmitriptan (ZTP) in tablets. These methods are based on the formation of yellow ion-pair complexes between ZTP and tropaeolin OO (TPOO) and bromothymol blue (BTB) in citrate-phosphate buffer of pH 4.0 and 6.0, respectively. The formed complexes were extracted with dichloromethane and measured at 411.5 and 410 nm for TPOO and BTB, respectively. The best conditions of the reactions were studied and optimized. Beer's law was obeyed in the concentration ranges of 2-20 and 1.5-17 microg/mL with molar absorptivities of 1.42 x 10(4) and 1.60 x 10(4) L/mol/cm for the TPOO and BTB methods, respectively. Correlation coefficients were 0.9998 and 0.9999 for TPOO and BTB methods, respectively. Limits of detection of the TPOO and BTB methods were 0.341 and 0.344 microg/mL, respectively, and the limits of quantitation were 1.034 and 1.051 microg/mL, respectively. Sandell's sensitivity and stability constant were also calculated. The proposed methods have been applied successfully for the analysis of the drug in its dosage forms. No interference was observed from excipients present in tablets. Statistical comparison of the results with those obtained by a high-performance liquid chromatography method showed excellent agreement and indicated no significant differences in accuracy and precision.

Extractive spectrophotometric method for determination of carvedilol in tablets

A sensitive and rapid extractive spectrophotometer method has been developed for the assay of carvedilol in pharmaceutical formulations. The method is based on the formation of a chloroform soluble ion-pair complex between carvedilol and bromocresol green in an acidic medium. The complex shows absorption maximum at 415 nm and the system obeys Beer's law in the concentration range of 5-25 µg/ml. The results obtained by the proposed method were validated statistically and by recovery studies.

Extraction spectrophotometric determination of aluminum in dialysis concentrates with 3,5-ditertbutylsalicylfluorone and ionic liquid 1-butyl-3-trimethylsilylimidazolium hexafluorophosphate

The paper describes a highly sensitive and selective extraction spectrophotometric method for determination of aluminum in dialysis concentrates with new reagent 3,5-ditertbutylsalicylfluorone abbreviated as DTBSF, in which the ionic liquid 1-butyl-3-trimethylsilylimidazolium hexafluorophosphate abbreviated as [C 4tmsim][PF 6] was used as novel medium for liquid/liquid extraction of aluminum(III). Under optimal condition, DTBSF reacted with aluminum(III) to form a neutral Al–DTBSF complex rapidly, the complex was then extracted into the [C 4tmsim][PF 6] phase, the absorbance of the complex in ionic liquid at 542 nm was recorded and used to determine aluminum(III). The apparent molar absorptivity of the complex and detection limit were found to be 3.52 × 10 6 l mol −1 cm −1 and 0.06 μg/l, respectively. The absorbance of the complex at 542 nm increases linearly with the concentration of aluminum(III) up to 3 μg of aluminum(III) in 250 ml of aqueous solution. The interference study show the determination of aluminum is free from interferences of almost all positive and negative ions found in dialysis concentrate samples. The determination of aluminum in dialysis concentrates were carried out by the present method and electrothermal atomic absorption spectrometry (GTAAS). The results were satisfactorily comparable so that the applicability of the proposed method with the ionic liquid system was also investigated. Moreover, the synthesis of and conditions for the formation and extraction of Al–DTBSF complex were investigated as well.

A Novel Room Temperature Ionic Liquid Extraction Spectrophotometric Determination of Trace Germanium in Natural Water with Methybenzeneazosalicylfluorone

This paper describes a highly sensitive and selective extraction spectrophotometric method for determination of trace germanium in natural water with new a chromogenic reagent methybenzeneazosalicylfluorone abbreviated as MBASF, in which a typical room temperature ionic liquid, 1‐butyl‐3‐methylimidazolium hexafluorophosphate abbreviated as [C4mim][PF6] was used as novel medium for liquid/liquid extraction of germanium(IV). In the presence of TritonX‐100, MBASF reacted with germanium(IV) to form a red complex rapidly, the complex was then extracted into the [C4mim][PF6] phase, the absorbance of the complex in ionic liquid at 496 nm was recorded and used to determine trace germanium(IV). The apparent molar absorptivity of the complex and the detection limit for the real sample were found to be 3.12×106 L mol−1 cm−1 and 0.2 ng mL−1, respectively. The absorbance of the complex at 496 nm increases linearly with the concentration up to 4 µg of germanium (IV) in 250 mL of aqueous solution. The interference study show the determination of germanium is free from the interference of almost all positive and negative ions found in the natural water samples. The determination of germanium in natural water was carried out by the present method and electrothermal atomic absorption spectrometry (AAS). The results were satisfactorily comparable so that the applicability of the proposed method was confirmed using the real samples. Moreover, the extraction mechanism with the ionic liquid system was also investigated. We think the extraction performance of the ionic liquid system is a combination of ion‐pairing effect between imidazolium cation and basic solute in the aqueous phase with the dissolution of polar molecule in ionic liquid phase. A wise choice of the appropriate combination of anion with imidazolium cation hydrophobicity allows playing with solute selectivity.

Investigation of the extraction equilibrium of ion-association complexes of molybdenum (VI) with some polyphenols and thiazolyl blue. extraction-spectrophotometric determination of molybdenum

Abstract The extraction process of ternary ion-association complexes of molybdenum (VI) with some polyphenols (4-nitrocatechol, 2,3-dihydroxy naphthalene) and thiazolyl blue has been investigated by using an extraction-spectrophotometric method. The optimum conditions for their quantitative preparation in aqueous medium and subsequent extraction into an organic solvent have been found. The extraction, distribution and association constants, and the recovery factors have been calculated. The composition of the complexes has been determined. A precise, sensitive and simple extraction-spectrophotometric method for determination of molybdenum in products from ferrous metallurgy has been developed.

Extraction-Spectrophotometric Method for Determination of Fluoride in the Range of Microgram per Liter in Natural Waters

In this study a new extraction–spectrophotometric method for the determination of fluoride ion in natural waters has been presented by use of octyl chemically bonded solid phase extraction (SPE) cartridge. In this method at first aluminium–oxinate chelate is adsorbed on SPE cartridge, then the water sample (containing fluoride ion) is passed through the SPE device. The excess of oxine on the sorbent is washed with acetate buffer and finally the residual of aluminium–oxinate chelate on the sorbent is eluted by ethanol and its absorbance is read at 375 nm. The decrease of adsorbed aluminium–oxinate chelate on sorbent is proportional to the fluoride ion concentration in the water samples. The detection limit of this method is 80 ng/ml and the linear dynamic range is between 0.1–2 µg/ml. Sensitivity of the method is excellent and absorbance variation for each µg/ml fluoride ion is 0.6 (approximately equal to Eriochrome cyanine R-zirconium standard method and ten times better than the Alizarin complexon standard method). Results of this method have good agreement with the Eriochrome cyanine R-zirconium standard method. Also this method has less interferences as compared with SPADNS standard method.

Extractive spectrophotometric methods for determination of diltiazem HCl in pharmaceutical formulations using bromothymol blue, bromophenol blue and bromocresol green

Three simple and sensitive extractive spectrophotometric methods have been described for the assay of diltiazem hydrochloride either in pure form or in pharmaceutical formulations. The developed methods involve formation of coloured chloroform extractable ion-pair complexes of the drug with bromothymol blue (BTB), bromophenol blue (BPB) and bromocresol green (BCG) in acidic medium. The extracted complexes showed absorbance maxima at 415 nm for all three methods. Beer's law is obeyed in the concentration ranges 2.5–20.0, 2.5–10.0 and 2.5–12.5 μg ml −1 with BTB, BPB and BCG, respectively. The methods have been applied to the determination of drug in commercial tablets and capsules. Results of analysis were validated statistically and through recovery studies.

Solvent extraction, spectrophotometric, and atomic absorption spectrophotometric determination of beryllium with heterocyclic hydroxamic acids

A simple, rapid, and selective method for extraction spectrophotometric determination of beryllium(II) is described. Beryllium is extracted with a chloroform solution of N-phenyl-2-furohydroxamic acid (PFHA) at pH 9.0. The beryllium(II)-hydroxamate complex extract is colorless and hence morin is added to the extract, which gives an intensely yellow-colored complex having a maximum absorbance at 420 nm with a molar absorptivity of 2.7 × 104 1 mol−1 cm−1. Common anions and cations do not interfere in the determination of beryllium. The spectral characteristics of beryllium complexes with eight beterocyclic hydroxamic acids are recorded. Beryllium is also determined by AAS and the results obtained are in agreement with those of the spectrophotometric method. The method is applied to the determination of beryllium in standard samples.

Extraction spectrophotometric method for determination of aluminium in silicates

A simple, rapid and sensitive method has been worked out for spectrophotometric determination of macro and micro amounts of alumina in ceramic raw materials and finished products, including glasses. The method is based on the extraction of aluminum oxinate into chloroform after masking of titanium with chromotropic acid and of iron with ascorbic acid and 1,10-phenanthroline or ferrocyanide at pH 5.2. The absorbance is measured at 385 nm. Interference by Cu, Zn, Cd, Ni and Co, when present, is overcome by stripping them as cyanide complexes by shaking the chloroform extract with potassium cyanide solution. Zr is masked with quinalizarin sulphonic acid and fluoride with BeSO 4.