Analytical Chemistry of Molybdenum

Parker, Gordon A.

doi:10.1007/978-3-642-68992-5

Cited by 63 publications

(30 citation statements)

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“…1). The appearance of samples blue color after treatment can testify the reducing of the initial molybdenum oxide [24]. The data obtained show an increase in intensity of blue color samples with an increase in treatment time or rotation speed (rpm).…”

Section: Resultsmentioning

confidence: 92%

Determination of molybdenum oxidation state on the mechanochemically treated MoO3

Kopachevska¹,

Melnyk²,

Bacherikova³

et al. 2015

Him. Fiz. Tehnol. Poverhni

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Section: Resultsmentioning

confidence: 92%

Determination of molybdenum oxidation state on the mechanochemically treated MoO3

Kopachevska¹,

Melnyk²,

Bacherikova³

et al. 2015

Him. Fiz. Tehnol. Poverhni

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“…A 0.1 g amount of a brass or alloy or steel sample containing 0.24-1.99% of vanadium was weighed accurately and placed in a 50 mL Erlenmeyer flask following a method recommended by Parker [24] to it, 10 mL of concentrated HNO3, 2 mL of concentrated H2SO4 and 1-2 mL of 1% KMnO4 were added to oxidize vanadium (IV) to vanadium (V), excess of KMnO4 was removed by addition of 1-2 mL of freshly prepared 2.5% sodium azide solution and carefully covering the flask with a watch glass until the brisk reaction subsided. The solution was heated to drive off excess azide solution and simmered gently after the addition of 5 mL of concentrated HNO3 until all carbides were decomposed.…”

Section: Determination Of Vanadium In Brass Alloys and Steels (Certimentioning

confidence: 99%

Highly sensitive spectrophotometric method for the determination of vanadium in environmental, biological, food and soil samples using orthoaminophenol

Zannat

Ahmed

2015

Eur. J. Chem.

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A simple, ultra-sensitive and highly selective non-extractive spectrophotometric method for the determination of trace amount of vanadium(V) using orthoamino phenol (OAP) has been developed. OAP reacts in highly acidic (0.005-0.015 mol/L H2SO4) and aqueous media with vanadium(V) to give a chocolate color chelate which has an absorption maximum at 405 nm. The reaction was instantaneous and absorbance remains stable for over 72 h. The average molar absorption co-efficient and Sandell's sensitivity were found to be 6.7×10 5 L/mol.cm and 10 ng/cm 2 of vanadium(V), respectively. Linear calibration graphs were obtained for 0.02-50.00 mg/L having detection limit 1 µg/L and quantification limit of the reaction were found to be 10 µg/L and RSD 0-2%. The stoichiometric composition of the chelate is 1:3 (Vanadium(V):OAP, v:v). Large excess of over 60 cations, anions and complexing agents (Like tartrate, EDTA, oxalate, chloride, phosphate, thiourea, SCN -etc.) do not interfere in the vanadium determination. The method was successfully used in the determination of vanadium in several standard reference materials (Alloys and steels) as well as in some environmental waters(Potable and polluted), biological samples (Human blood and urine), food samples, soil samples, solution containing both vanadium(IV) and vanadium(V) and complex synthetic mixtures. The results of the proposed method for biological analyses were found to be in excellent agreement with those obtained by AAS. The method has high precision and accuracy (s = ±0.01 for 0.5 µg/mL).

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“…Determination of cadmium in alloys and steels. A 0.1 g amount of an alloy or steel sample was accurately weighed into a 50 mL Erlenmeyer flask following a method recommended by Parker et al 17 To it, 10 mL of 20% (v/v) sulfuric acid was added, carefully covering with a watch-glass until the brisk reaction subsided. The solution was heated and simmered gently after the addition of 5 mL of concentrated HNO3 until all carbides were decomposed.…”

Section: Applicationsmentioning

confidence: 99%

A Simple Spectrophotometric Method for the Determination of Cadmium in Industrial, Environmental, Biological and Soil Samples Using 5,7-Dibromo-8-hydroxyquinoline

Ahmed

CHOWDHURY

2004

ANAL. SCI.

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Cadmium in trace amounts is important industrially, 1 as a toxicant 2 and biological non-essential, 3 as an environmental pollutant 4 and as an occupational hazard. 5 It is an extremely toxic metal, and has been responsible for a number of deaths. 6 Increasing cadmium pollution of the environment, resulting from the growth of cadmium based industries and the use of fossil fuels, makes the development of a method for the trace and ultra-trace analysis of this toxic metal essential.Spectrophotometry is essentially a trace-analysis technique and is one of the most powerful tools in chemical analysis. 5,7-Dibromo-8-hydroxyquinoline (DBHQ) has been reported to be a spectrophotometric reagent for vanadium 7 and molybdenum, 8 but has not previously been used for the spectrophotometric determination of cadmium. This paper reports on its use in a very sensitive, highly specific spectrophotometric method for the trace determination of cadmium. The method possesses distinct advantages over existing methods 9-11 with respect to sensitivity, selectivity, range of determination, simplicity, speed, pH/acidity range, thermal stability, accuracy, precision, and ease of operation. It is based on the reaction of nonabsorbent DBHQ in a slightly acidic solution (0.00015 -0.00065 M H2SO4) with cadmium to produce a highly absorbent greenish-yellow chelate product, followed by a direct measurement of the absorbance in aqueous solution. With suitable masking, the reaction can be made highly selective, and the reagent blank solutions do not show any absorbance. Experimental ApparatusA Shimadzu (Kyoto, Japan) (Model 160) double-beam UVVisible recording spectrophotometer and a Jenway (England, UK) (Model 3010) pH-meter with a combination of electrodes were used for measurements of the absorbance and pH, respectively. A Shimadzu (Kyoto, Japan) (Model AA6401F) atomic-absorption spectrophotometer equipped with a microcomputer-controlled nitrous oxide-acetylene flame was used to compare the results. Reagents and solutionsAll chemicals used were of analytical-reagent grade or the highest purity available. Doubly distilled deionized water and HPLC-grade absolute ethanol, which is non-absorbent under ultraviolet radiation, were used throughout. Glass vessels were cleaned by soaking in acidified solutions of KMnO4 or K2Cr2O7, followed by washing with nitric acid (1 + 1) and rinsed several times with high-purity deionized water. Stock solutions and environmental water samples (1000 mL each) were kept in polypropylene bottles containing 1 mL of concentrated HNO3. More rigorous contamination control was used when the cadmium levels in the specimens were low. DBHQ solution, 3.3 × 10 -3 MPrepared by dissolving the requisite amount of DBHQ (Merck, Darmstadt, Germany) in a known volume of distilled ethanol. More dilute solutions of the reagent were prepared as required. Cadmium standard solution, 8.89 × 10-3 M A 100-mL amount of stock solution (1 mg mL -1 ) of divalent cadmium was prepared by dissolving 0.2282 mg of A. R. crystallized cadmium sulfate (3C...

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Analytical Chemistry of Molybdenum

Cited by 63 publications

References 0 publications

Determination of molybdenum oxidation state on the mechanochemically treated MoO3

Determination of molybdenum oxidation state on the mechanochemically treated MoO3

Highly sensitive spectrophotometric method for the determination of vanadium in environmental, biological, food and soil samples using orthoaminophenol

A Simple Spectrophotometric Method for the Determination of Cadmium in Industrial, Environmental, Biological and Soil Samples Using 5,7-Dibromo-8-hydroxyquinoline

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