Variaminblau als colorimetrisches Reagens

Erdey, L.; Szabadváry, Franz

doi:10.1007/bf00475103

Cited by 9 publications

(4 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The high difference in the molar absorbitivty between both oxidized and reduced forms (about 6000‐fold) greatly improves the sensitivity of the catalytic method. The reaction mechanism seemed to undergo through oxidation of iodide to iodine, the liberated iodine can oxidize VB present in the reaction medium producing a deep violet blue colour through the transfer of two electrons to give rise to N‐(4‐methoxyphenyl)‐quinonedimine (VB ox ) 34…”

Section: Resultsmentioning

confidence: 99%

“…The reaction mechanism seemed to undergo through oxidation of iodide to iodine, the liberated iodine can oxidize VB present in the reaction medium producing a deep violet blue colour through the transfer of two electrons to give rise to N-(4-methoxyphenyl)quinonedimine (VB ox ). [34] The reaction variables such as reactant concentrations, reaction temperature, and the influence of acidic medium were optimized to achieve the highest sensitivity of the method. It was found that oxidation of iodide takes place in acidic medium, and the catalyzed reaction in H 3 PO 4 was higher than in other tested acidic media (H 2 SO 4 , HCl, HNO 3 or acetic acid).…”

Section: Variamine Blue Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Catalytic spectrophotometric determination of iodide in pharmaceutical preparations and edible salt

El-Ries

Khaled

Zidane

et al. 2011

Drug Testing and Analysis

View full text Add to dashboard Cite

The catalytic effect of iodide on the oxidation of four dyes: viz. variamine blue (VB), methylene blue (MB), rhodamine B (RB), and malachite green (MG) with different oxidizing agents was investigated for the kinetic spectrophotometric determination of iodide. The above catalyzed reactions were monitored spectrophotometrically by following the change in dye absorbances at 544, 558, 660, or 617 nm for the VB, RB, MB, or MG catalyzed reactions, respectively. Under optimum conditions, iodide can be determined within the concentration levels 0.064-1.27 µg mL(-1) for VB method, 3.20-9.54 µg mL(-1) for RB method, 5.00-19.00 µg mL(-1) for the MB method, and 6.4-19.0 µg mL(-1) for the MG one, with detection limit reaching 0.004 µg mL(-1) iodide. The reported methods were highly sensitive, selective, and free from most interference. Applying the proposed procedures, trace amounts of iodide in pharmaceutical and edible salt samples were successfully determined without separation or pretreatment steps.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Variamine Blue Methodsmentioning

confidence: 99%

Catalytic spectrophotometric determination of iodide in pharmaceutical preparations and edible salt

El-Ries

Khaled

Zidane

et al. 2011

Drug Testing and Analysis

View full text Add to dashboard Cite

show abstract

“…This reagent is soluble in water and produces a colorless solution which turns blue violet meriquinone which absorbs at 570-610 nm upon oxidation (3) .…”

mentioning

confidence: 99%

“…VB Reduced, colorless VB Oxidized, violet VB was recommended as redox indicator for potentiometric and visual titrations with Fe (III) (3,4) , bromamine-B (5) or bromate (6) . More recently, Basavaiah and Charan used VB for the assay of methdilazine in bulk drug applying potassium iodate as oxidant (7) .…”

mentioning

confidence: 99%

Novel Variamine Blue Potentiometric Sensor

2010

Egypt. J. Chem.

View full text Add to dashboard Cite

OVEL polyvinyl chloride (PVC) potentiometric sensors are constructed for determination of variamine blue (VB). Different methods for electrode fabrication including; modification with the VB-TPB ion pair, modification with sodium tetraphenylborate or soaking of the plain electrode in the ion-pair suspension, have been described. Electrode matrix compositions were optimized on the basis of effects of type and content of the modifier as well as influence of the plasticizers. The fabricated electrodes worked satisfactorily in the concentration range from 10 -6 to 10 -2 M of VB. Electrodes modified with VB-TPB showed the best performance (Nernstian slope 62.0±0.7 mV decade -1 ) with fast response time of about 8 sec and adequate lifetime (4 weeks). The developed electrodes have been successfully applied as end point indicator electrode for the potentiometric titration of 6.75-20.25 mg VB with high accuracy and precision. The solubility products of different VB ion-pair were determined conductometrically.

show abstract

Redoxreaktionen an Ionenaustauschern und ihre analytischen Anwendungen

Inczédy¹

1962

Zeitschrift fuer Chemie

View full text Add to dashboard Cite

Variaminblau als colorimetrisches Reagens

Cited by 9 publications

References 1 publication

Catalytic spectrophotometric determination of iodide in pharmaceutical preparations and edible salt

Catalytic spectrophotometric determination of iodide in pharmaceutical preparations and edible salt

Novel Variamine Blue Potentiometric Sensor

Redoxreaktionen an Ionenaustauschern und ihre analytischen Anwendungen

Contact Info

Product

Resources

About