Spectrophotometric Determination of Sulphathiazole

Abstract

A new, rapid, simple, selective and sensitive method for the spectrophotometric determination of sulphathiazole is described. The drug forms a yellow coloured complex with Pd(II) in alkaline medium (1 M NaOH). The drug complex exhibits maximum absorbance at 410 nm, with a molar absorptivity of 1.9 × 10³ 1 mol^?1 cm^?1. Effects of molarity of NaOH, reagent concentration on the proper complex formation are discussed. The system obeys Beer's law in the concentration range of 10-160 ppm of sulphathiazole.     

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.     

Novel Reaction for Rapid,Simple, and Sensitive Determination of Molybdenum in Various Samples

Abstract

A new sensitive, selective, rapid, and reproducible method is presented for the analysis of trace amounts of molybdenum (VI) (Mo(VI)). The method is based on the reaction of molybdenum (VI) with a new analytical reagent, 6‐(5‐Chloro‐2‐hydroxy‐4‐sulfophenylazo)‐5‐hydroxy‐1‐naphthalenesulfonic acid, disodium salt. Under optimum reaction conditions, molybdenum (VI) forms a red complex with a maximum absorption peak at 589 nm. The color reaction is rapidly completed at room temperature. The apparent molar absorption coefficient and Sandell sensitivity were 1.13×10⁴ L · mol^?1 · cm^?1 and 0.0084 µg · cm^?2, respectively. Beer's law was obeyed up to 8.5 µg · mL^?1. Methods for the determination of Mo(VI) by first‐derivative spectrophtometry have also been proposed at 547 and 625 nm. The proposed methods offer the advantages of sensitivity, rapidity, selectivity, and simplicity without any prior separation or extraction. The methods have been applied to the determination of Mo(VI) in various environmental samples and some alloys; satisfactory results have been obtained.     

Colorimetric Determination of Seleniumin Various Environmental Samples

A new reagent system using rhodamine‐B dye for the determination of selenium is described. The method is based on the reaction of selenium with acidified potassium iodide to liberate iodine. The liberated iodine bleaches the pink colour rhodamine‐B, which is measured at 555 nm. Beer's law is obeyed over the concentration range of 1–10 μg of selenium final solution volume of 25 mL (0.04–0.4 ppm) and the apparent molar absorptivity and Sandell's sensitivity was found to be 1.96× 10⁵ l mol^?1 cm^?1 and 0.0004 μg cm^?2, respectively. The method is simple, sensitive, and selective and is satisfactorily applied to micro‐level determination of selenium in various environmental and cosmetic samples.     

A Sensitive Colorimetric Reagent for the Determination of Cyanide and Hydrogen Cyanide in Various Environmental Samples

A sensitive reagent system is proposed for the determination of cyanide and hydrogen cyanide in various environmental samples. The method is based on the conversion of cyanide into cyanogen bromide followed by its reaction with pyridine to form glutaconic aldehyde. The glutaconic aldehyde so formed is coupled with p‐aminoacetophenone forming yellow‐orange polymethine dye measured at 445 nm. The colour system obeys Beer's law in the range of 0.01–0.16 ppm of cyanide inaqeous phase and 0.002–0.03 ppm in extracting system. The molar absorptivity and Sandell's sensitivity were found to be 6.51 × 10⁵ l mol^?1 cm^?1 and 0.0001 μg cm^?2, respectively. The method has been successfully applied for the determination of cyanide in air, industrial effluent, biological samples, and in the pesticide acrylonitrile.     

Sensitive Spectrophotometric Determination of Copper(II) in the Presence of Manganese

Abstract

This paper recommends a simple and convenient procedure for the determination of copper(II) in the presence of large amounts of manganese. An aqueous solution of hydroxylamine hydrochloride and diluted sulphuric acid was used for dissolution and reduction of MnO₂. The copper(II) was complexed with an ethanolic 0.05% PAN solution in the pH range of 2 - 3 in aqueous medium. The absorbances of copper-PAN complexes are measured at 550 nm where molar absorptivity is 2.10 L.mol^?1.cm^?1.

The complex obeys Beer's Law from 0.1 to 4 ppm. of copper. Manganese(II) up to 1000 ppm. doesn't interfere. The method is sensitive and reproducible.

It has been applied to the analysis of samples containing 0.01 to 5% of copper on manganese dioxide catalysts.     

A Rapid,Simple, and Sensitive Spectrophotometric Determination of Traces of Vanadium (V) in Foodstuffs,Alloy Steels,and Pharmaceutical,Water, Soil,and Urine Samples

Abstract

A rapid, simple, sensitive, and selective spectrophotometric method is investigated for the determination of traces of vanadium (V) in foodstuffs, alloy steels, and pharmaceutical, water, soil, and urine samples in aqueous DMF medium. The metal ion forms a green colored complex with 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) in an acidic buffer of pH 6.0. The green colored solution, having an absorbance maximum at 380 nm, is stable for more than 72 hours. Beer's law is obeyed in the range of 0.051–2.037 µg ml^?1. The molar absorptivity and Sandell's sensitivity of the method are found as 2.75 × 10⁴ l mol^?1 cm^?1 and 0.0018 µg cm^?2, respectively. The green colored complex has 1:2 [V(V)-HMBATSC] stoichiometry. The stability constant of the complex is determined as 3.267 × 10¹¹ by Job's method. The optimum reaction conditions and other analytical parameters are studied. A sensitive and selective second-order derivative spectrophotometry has also been proposed for the determination of V(V). The interference of various cations and anions are studied. The present method is successfully applied to the determination of vanadium (V) in foodstuffs, alloy steels, and pharmaceutical, water, soil, and urine samples.     

Spectrophotometric determination of copper(II) and its application to a plant sample containing zinc,iron, and manganese

Salicylaldehyde thiosemicarbazone instantaneously forms a green complex with copper(II) in the optimum pH range 5–7. A fivefold molar excess of the reagent is sufficient for the full development of the color. Beer's law is obeyed in the range 0.5–6.0 ppm of copper. The optimum concentration range as evaluated by Ringbom's method is 1.4–5.8 ppm. At 375 nm the sensitivity of the reaction and the molar absorptivity are 0.006 μg cm^?2 and 9.2 × 10³ liters mol^?1 cm^?1, respectively. The effects of pH, reagent concentration, time, order of addition of the solutions, and the interference of various ions were investigated. Copper in plant samples, containing zinc, iron, and manganese, was determined.     

Determination of Vanadium with Chlorosubstituted Hydroxamic Acids for Photometric and Atomic Absorption Spectrophotometric Determination

Abstract

The eight newly synthesized chlorosubstituted hydroxamic acids are described for the extraction and spectrophotometric determination of vanadium. The sensitive and selective reagent, N-m-Chlorophenylpalmito hydroxamic acid, (m-CPPHA), which gives violet coloured vanadium complex was extracted with chloroform from 6M HCl. The violet coloured complex thus obtained has a maximum absorbance at 520 nm and molar absorptivity 4.9 ± 10³1mol^?1cm^?1. The Beer's law obeyed in the region 0.50-12.0ppm. Effects of acidity, reagent concentration, diverse ions have also been investigated. A comparison has been made with atomic absorption spectrophotometric method. Vanadium has been determined in the environment, e.g. plant, soil, rock, etc.     

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.     

Rapid Extraction Spectrophotometric Determination of Platinum Using Anisaldehyde-4-Phenyl-3-Thiosemicarbazone as a Chromogenic Reagent

Abstract

The synthesis, spectral characteristics and analytical applications of anisaldehyde-4-phenyl-3-thiosemicarbazone (APT) are described. A simple, rapid, selective and sensitive spectrophotometric method for the determination of platinum was developed based on the colour reaction between platinum (IV) and anisaldehyde-4-phenyl-3-thio-semicarbazone (APT) in the pH range 1.7 - 3.0. The yellow coloured species has an absorption maximum at 360 nm. The complexation is complete within 1 min. A five-fold excess of the reagent is required for complete complex formation. Beer's law is obeyed over the concentration range 0.1 -20 ppm of Pt(IV). The mtilar absorptivity and Sandell's sensitivity are 1.58 × 10⁴ l. mol^?1 cm^?1 and 0.0123 ug of Pt(IV) cm^?2, respectively. The effects of pH, time concentration of reagent, order of addition of reagents and the interference from various ions were investigated. The method has been employed for the determination of platinum in synthetic mixtures whose composition correspond to some alloys.     

Simple and Simultaneous Method for Determination of Palladium(II) and Ruthenium(III) using Second-Order-Derivative Spectrophotometry

Abstract

A simple, sensitive, and selective second-order-derivative spectrophotometric method has been developed for the simultaneous determination of palladium(II) and ruthenium(III) using 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) as a chromophoric reagent. The reagent (HMBATSC) reacts with Pd(II) and Ru(III) at pH 3.0, forming soluble yellowish green and dark brown species, respectively. Palladium and ruthenium present in the mixture were simultaneously determined without solving the simultaneous equations by measuring the second derivative amplitudes at 445 nm and 385 nm, respectively. Further, the Beer's law was obeyed in the range 0.21–12.78 µg mL^?1 and 0.25–13.42 µg mL^?1 for Pd(II) and Ru(III), respectively. A large number of foreign ions did not interfere in the present method. The proposed method was successfully applied for the determination of palladium in hydrogenation catalysts and ruthenium in water samples.     

Synthesis of New Reagent Benzyloxybenzaldehydethiosemicarbazone (BBTSC): Selective,Sensitive and Extractive Spectrophotometric Determination of Pd(II) in Water Samples and Synthetic Mixtures

A new reagent, benzyloxybenzaldehydethiosemicarbazone (BBTSC) was synthesized and a new method was developed for the simple, highly selective and extractive spectrophotometric determination of palladium(II) with BBTSC at wave length 365 nm. The metal ion formed a yellow colored complex with BBTSC in acetate buffer of pH 5.0, which was easily extractable into cyclohexanol with 1:1 (Metal: Ligand) composition. The method obeys Beer's law in the range of 5–60 ppm. The molar absorptivity and Sandell's sensitivity were found to be 0.4 × 10⁴ Lt. mol^?1 cm^?1 and 0.02661 μg cm^?2, respectively. The correlation co‐efficient of the Pd(II)‐BBTSC complex was 0.9657, which indicated an excellent linearity between the two variables. The repeatability of the method was checked by finding the relative standard deviation (RSD) (n = 10), which was 0.321% and its detection limit 0.016875 μg.mL^?1. The instability constant of the method was calculated by Asmus' method as 3.5714 × 10^?4. The interfering effect of various cations and anions were also studied. The proposed method was successfully applied for the determination of palladium(II) in synthetic and water samples. The results were compared with those obtained using an atomic absorption spectrophotometer, testing the validity of the method.     

Synthesis of New Reagent 2,6‐Diacetylpyridine Bis‐4‐Phenyl‐3‐Thiosemicarbazone (2,6‐DAPBPTSC): Selective,Sensitive and Extractive Spectrophotometric Determination of Co(II) in Vegetable,Soil, Pharmaceutical and Alloy Samples

New synthesized reagent 2,6‐diacetylpyridine bis‐4‐phenyl‐3‐thiosemicarbazone (2,6‐DAPBPTSC) is proposed as a sensitive and selective analytical reagent for the extractive spectrophotometric determination of cobalt(II). Cobalt(II) forms a reddish brown colored complex with 2,6‐DAPBPTSC, which is extracted into isoamylalcohol, under optimum conditions. The maximum absorption of the isoamylalcohol extract is measured at 400 nm. Beer's law is applied in the range 0.6‐6.0 ppm of cobalt(II). The molar absorptivity and Sandell's sensitivity of the complex is calculated as 2.2 × 10⁴ L mol^?1 cm^?1 and 2.68 × 10^?3 μg cm^?2, respectively. An adequate linearity with a correlation coefficient value of 0.969 is obtained for the Co(II)‐2,6‐DAPBPTSC complex. The instability constant of the complex, calculated from Asmus' method is 3.75 × 10^?4 The precision and accuracy of the method is checked with calculation of relative standard deviation (n = 5), 0.388 and the detection limit a value is 0.0028 μg mL^?1. The method is successfully employed for the determination of cobalt(II) in real samples, such as vegetables, soil, water samples, standard alloy samples, and the performance of the present method was evaluated in terms of Student ‘t’ test and Variance ‘f’ test, which indicates the significance of the present method is an inter comparison of the experimental values, using atomic absorption spectrometer (AAS).     

Isonitroso-4-Methyl-2-Pentanone for Solvent Extraction and Spectrophotometric Determination of Palladium (II) at Trace Level

Abstract

Isonitroso-4-methyl-2-pentanone (HIMP) is proposed as a new reagent for extraction and photometric determination of Pd(II). The reagent forms a yellow complex with palladium in the pH range 4.0-5.0. The complex extracted into chloroform was measured at 330 nm. The molar absorptivity was found to be 5.37 × 10³ 1 mol^?1 cm^?1 and Sandell's sensitivity 20 ng cm^?2 Beer's law was obeyed over the concentration range 0.1-10.0 μg/ml of palladium. The method is applicable for palladium estimation in Ores and catalysts.     

2‐Aminocyclopentene‐1‐Dithiocarboxylic Acid‐Naphthalene Adsorbent for the Preconcentration and Determination of a Trace Copper in Real Samples by Spectrophotometric Method

A solid uncharged complex produced from 2‐aminocyclopentene‐1‐dithiocarboxylic acid (synthetic reagent) on naphthalene provides a very sensitive, selective and economical method for the preconcentration and determination of trace amounts of copper in drug and alloy samples. The 2‐aminocyclopentene‐1‐dithiocarboxylate of copper is retained quantitatively on microcrystalline naphthalene in the pH range 2.8–3.3. After filtration the solid mass consisting of copper complex‐naphthalene is dissolved with 4 mL of dimethylformamide (DMF). The absorbance is measured at 462 nm with a spectrophotometer against the reagent blank and molar absorptivity found to be 2.8 × 10⁵ liter mol^?1 cm^?1. Beer's law is obeyed over the concentration range of 0.1–16.0 μg of copper in 4 mL of the dimethylformamide solution. Detection limit is 3 ng mL^?1 [signal to noise ratio = 2]. Ten replicate determinations on a sample containing 1 μg of copper gave a relative standard deviation of 0.76%. The interference of a large number of anions and cations have been studied and the optimized conditions developed were utilized for determination of copper in various real samples.     

Spectrophotometric Determination of Cadmium(II) Using p,p′‐Dinitro‐SYM‐Diphenylcarbazid in Aqueous Solutions

Abstract

A sensitive and selective spectrophotometric method is proposed for the rapid determination of cadmium(II) using, p,p′‐dinitro‐sym‐diphenylcarbazid, directly in aqueous solution. The reaction between cadmium(II) and p,p′‐dinitro‐sym‐diphenylcarbazid occurs immediately in strong basic media (0.02 N sodium hydroxide solution). The complex shows a maximum of absorption at 630–640 nm, and the absorbance remains stable for at least 24 h. The method allows the cadmium determination over the range 0.5–6.0 µg mL^?1, with a molar absortivity of 2.05×10⁴ L mol^?1 cm^?1 and features a detection limit of 0.13 ppm. The interferences caused by several ions [Ca(II), K(I), Ba(II), Al(III), Pb(II), Zn(II), Cl^?1, NO₃ ^?, SO₄ ^2?], which are present in most of environmental samples, were determined. The validation of the spectrophotometric method was done by recovery test of cadmium(II) in tap water and sea water. The results show that the proposed method has been successfully applied to the determination of cadmium(II) in water samples.     

Spectrometric Determination of Nitrite in Aqueous Solution by the Diazotization-Coupling Method with p-Aminobenzophenone-N-(1-Naphthyl)-Ethylenediamine

Abstract

Nitrite ion at low concentration is determined spectrometrically by diazotization of p-aminobenzo-phenone and coupling of the resulting diazonium cation with N-(1-naphthy1)-ethylene-diamine to form a reddish-violet coloured water-soluble azo dye with maximum absorption at 555 nm. The method is suitable for the determination of nitrite over the range of 0.04–1.00 ppm. Beer's law is obeyed over this range of concentrations. The observed molar absorptivity and Sandell's sensitivity of the azo dye are 7.0 × 10⁴ mol^?1 cm^?1 and 6.5 × 10^?4 μg cm^?2, respectively. Interferences due to other ions were studied to test the selectivity.     

Increased Sensitivity Spectrophotometric Flow Analysis Method for Copper Determination in Water Samples

A reverse configured flow injection system was developed for the determination of copper in water samples. In this study, a bathocuproine disulfonic acid copper complexing reagent was used. In the presence of a reducing agent (hydroxylamine), the formation of complex was monitored at 484 nm. The determination range extended from 1 to 40 µg L^?1, with an applicable determination rate of 40 h^?1. The developed method was applied to the determination of copper in water samples (estuarine, river, and drinking water) and showed good accuracy (z-score below 2). The detection limit of 0.7 µg L^?1 copper is consistent with the requirement of the target water samples. The developed method was also used for the comparison of different spectrophotometric flow cells. Alternative flow cells (U, Z shaped, and the liquid waveguide capillary cell) were compared in terms of their sensitivity and response to refractive index changes.     

Spectrophotometer Determination of Nitrite Using Salbutamol sulphate as a Reagent

Abstract

A simple spectrophotometric method for the trace determination of nitrite (NO^? ₂) is described. Nitrite is reacted with Salbutamal sulphate in acidic medium which gives a yellow colour in alkaline medium (?pH 7) and can be determined in the presence of several cations and anions. Beer's law is obeyed in the range of 1.8 to 27.6 ppm of nitrite with the molar absorptivity 1.8 × 10³ 1 × mole^?1 × cm^?1 at 4l0 nm. The proposed method can also be utilized for the determination of nitrate (NO^? ₃) after its reduction to nitrite. The method has been applied for the determination of various samples containing traces of nitrite.