scholarly journals Determination of Chromium in Tannery Effluent and Study of Adsorption of Cr (VI) on Saw dust and Charcoal from Sugarcane Bagasses

1970 ◽  
Vol 23 ◽  
pp. 93-101 ◽  
Author(s):  
T. P. Dhungana ◽  
P. N. Yadav

Spectrophotometric method using diphenylcarbazide as a colour developing reagent has been used to analyze the chromium content in tannery effluent located in Bara and Parsa districts of Nepal and Sirsiya River which is an ultimate drainage of these waste water streams. The adsorption of hexavalent chromium from aqueous solution onto formaldehyde treated sawdust and charcoal of sugarcane begasses has been investigated at various Cr(VI) concentrations of 5-40 mg/L and pH values. From the experimental observations, it has been found that chromium can be removed quantitatively at the equilibrium pH range of around 1 and the adsorption behavior revealed to follow Langmuir and Freundlich adsorption isotherms.Keywords : chromium, diphenylcarbazide, adsorption.DOI: 10.3126/jncs.v23i0.2102Journal of Nepal Chemical Society, Vol. 23, 2008/2009 Page; 93-101

Author(s):  
Datta B. Mandhare ◽  
Vasant D. Barhate

Objective: A simple spectrophotometric method has been developed for the determination of Iron (III) by using Schiff base 2-[(2-hydroxyphenylimino) methyl]-4-nitrophenol [HPIMNP].Methods: HPIMNP extracts Fe (III) quantitatively (99.95%) into chloroform from an aqueous solution of pH range 4.0-6.0.Results: The chloroform extracts show maximum absorption at 510 nm (λ max). Beer’s Law is obeyed over the Fe (III) concentration range of 0.5 to 20.0 µg/ml. The Molar absorptivity and Sandell’s sensitivity for Fe–HPIMNP system is 5000 L mol ˉ1 cmˉ1 and 0.011 µg cmˉ2respectively. The composition of extracted species is found to be 1: 3 [Fe-HPIMNP] by Job’s continuous variation and Mole-ratio method. Interference by various ions has been studied.Conclusion: The proposed method is rapid, sensitive, reproducible and accurate and it has been satisfactory applied for the determination of Iron in Pharmaceutical Samples.


1969 ◽  
Vol 114 (3) ◽  
pp. 629-633 ◽  
Author(s):  
Kenji Soda ◽  
Takamitsu Yorifuji ◽  
Haruo Misono ◽  
Mitsuaki Moriguchi

A spectrophotometric method with 3-methyl-2-benzothiazolone hydrazone hydrochloride was developed for the determination of pyridoxal and pyridoxal 5′-phosphate, and for the selective determination of each in the presence of the other. Pyridoxal and pyridoxal 5′-phosphate react with the reagent to yield the azine derivatives, which give characteristic absorption spectra. The highest extinction values are obtained when pyridoxal and pyridoxal 5′-phosphate are incubated at pH values of about 3·4 and 8·0 respectively; their maxima are at 430nm. (∈ 2·74×104) and 380nm. (∈ 2·24×104) respectively. The azine of pyridoxal is only slightly soluble under the neutral and alkaline conditions, whereas that of pyridoxal 5′-phosphate is substantially insoluble in the acid pH range. This difference in solubility of the azines made possible the selective determination of pyridoxal and pyridoxal 5′-phosphate. α-Oxoglutarate and pyruvate are among the substances shown not to interfere with the assay of pyridoxal; their derivatives absorb appreciably only at wavelengths below 420nm. For the assay of pyridoxal 5′-phosphate in the presence of these compounds measurement at 390nm. is necessary.


Author(s):  
Mrs. Ritika Makhijani

Rh (III) was determined by simple, sensitive & feasible spectrophotometric method by using analytical reagent N - (o - methoxy benzaldehyde) 2-aminophenol (NOMBAP) . Elemental analysis was used to characterize synthesized Schiff’s base NOMBAP. Rh (III) is extracted quantitatively (99.66%) by NOMBAP into carbon tetra chloride from an aqueous solution having pH range 5.1 – 5.9. An intense peak at 480 nm (λ max) was observed in the extract of n-amyl alcohol. Beer’s law is obeyed over the concentration range 1.0 – 10.0 µg/ml for Rh (III). The molar absorptivity and Sandel’s sensitivity for Rh - NOMBAP system is 8248.23 dm3 mole-1cm-1and 0.08332 μgcm-2 respectively. Mole Ratio & Job’s Continuous Variation and Method show that the extracted species has composition 1:3 (Rh-NOMBAP). Study has been done for interference by various ions. For determination of Rh (III) in alloy the proposed method has been used.


2013 ◽  
Vol 10 (3) ◽  
pp. 965-970
Author(s):  
Baghdad Science Journal

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of captopril in aqueous solution. The method is based on reaction of captopril with 2,3-dichloro 1,4- naphthoquinon(Dichlone) in neutral medium to form a stable yellow colored product which shows maximum absorption at 347 nm with molar absorptivity of 5.6 ×103 L.mole-1. cm-1. The proposed method is applied successfully for determination of captopril in commercial pharmaceutical tablets.


2003 ◽  
Vol 68 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Randjel Mihajlovic ◽  
Natasa Ignjatovic ◽  
Marija Todorovic ◽  
Ivanka Holclajtner-Antunovic ◽  
Vesna Kaljevic

A modified spectrophotometric method using the bismuth phosphomolybdate complex for the determination of phosphorus in coal and coal ash is suggested. Bismuth together with phosphate and molybdate forms a very stable complex in acid medium which turns blue ("molibdenum blue") by reduction with ascorbic acid. The apparent molar absorptivity of PBiMo is 1.66x104 dm3 mol-1cm-1 at 720 nm and 2.10x104 dm3 mol-1cm-1 at 670 nm isobutyl methyl ketone (MIBK). Interference caused by the ions present are within the tolerance limits (?2 %). Beer?s law is obeyed in the for concentration range to 0.6 ?g/mL (aqueous solution) and to 1.2 ?g/mL P (MIBK). The sensitivity of the proposed method is 0.0078 ?g/mL (aqueous solution) and 0.0066 ?g/mL (MIBK).


1987 ◽  
Vol 70 (3) ◽  
pp. 588-590
Author(s):  
Anna-Maija K Sjoberg ◽  
Timo A Alanko

Abstract A spectrophotometric method for the determination of cyclamate was collaboratively studied in 9 laboratories. Ethyl acetate is added to extract cyclamate from acidic aqueous solution into water, and the cyclamate is then quantitatively converted to /V,./V-dichlorocyclohexylamine by adding excess hypochlorite. A',A'-Dichlorocyclohexylamine is determined by measuring its UV absorption at 314 nm. Six samples, 3 soft drinks with cyclamate levels of 0.36-0.47 g/kg and 3 jams with levels of 1.23-1.50 g/kg, were included in the study. Average recoveries of cyclamate were 99.7% in the soft drinks and 103.8% in the jams. Reproducibility coefficients of variation were 6.7% for the soft drinks and 4.4% for the jams.


1984 ◽  
Vol 67 (1) ◽  
pp. 117-122 ◽  
Author(s):  
J R Rangaswamy

Abstract A method has been developed for determination of phosphine residues in wheat, based on the reaction of phosphine with silver nitrate in aqueous solution to form an egg-yellow chromophore with an absorption maximum at 400 nm. At this wavelength, there is a linear relationship between absorbance and concentration of phosphine in the range 10–100 ng/mL. Phosphine-fumigated wheat is soaked in a known volume of AgNO3 solution, and the absorbance of the filtrate is read against a blank at 400 nm. The method is sensitive, with lower detection and estimation limits of 0.008 and 0.01 μg PH3, respectively. Recovery of added phosphine from a closed system was 85–100%. Accuracy for this method has been compared with that for the gas chromatographic method.


1963 ◽  
Vol 41 (7) ◽  
pp. 1662-1670 ◽  
Author(s):  
R. Greenhalgh ◽  
R. M. Heggie ◽  
M. A. Weinberger

Nuclear magnetic resonance has been used to follow the decomposition of aqueous solutions of 2-methyl-Δ2-oxazoline (0.29 M) at constant pH values in the range −1 to 14. The decomposition is first order with respect to total oxazoline at any specific pH, but deviates from the simple reaction of water with the protonated species above pH 5. At neutral pH values this is shown to be partially due to a second reaction involving 2-methyl-Δ2-oxazoline and O-acetylethanolamine which yields N-2-acetoxyethyl N′-2-hydroxyethyl acetamidate. The decrease in rate constant at pH < 2 is accounted for by variation in the water concentration, which is related to the acidity function. A kinetic expression is derived for the decomposition over the whole pH range studied. The decomposition of the amidate is also discussed.


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