A sensitive spectrophotometric method for the determination of silver is described. The reaction involves a silver-enhanced reduction of 2,3,5-triphenyl-2H-tetrazolium chloride by semicarbazide hydrochloride to yield a pink-colored product with maximum absorption at 510 nm. Beer's law is obeyed in the concentration range of 0.02-0.34 microg cm(-3) of silver, and the molar absorptivity is 4.51 x...

The near infrared absorption of pure n-heptane between 5000 c m 1 and 6500 c m 1 was measured up to 250 °C and to pressures of 2000 bar. The procedure for measuring vibrational intensities at high pressures and temperatures with a precision of better than ± 1% is described. The integrated molar absorptivity of the combination mode va + vs of the methylene stretching fundamentals turns out to be...

We present an ultrabroadband thin-film infrared absorber made of sawtoothed anisotropic metamaterial. Absorptivity of higher than 95% at normal incidence is supported in a wide range of frequencies, where the full absorption width at half-maximum is about 86%. Such property is retained well at a very wide range of incident angles too. Light of shorter wavelengths are harvested at upper parts of...

Alpha-benzilmonoxime in sodium dodecylsulfate micellar media has been used for the spectrophotometric determination of cobalt at pH 9.0. The linear range of calibration is 0.05-1.50 microg cm(-3) of cobalt at 380 nm with molar absorptivity of 3.72 x 10(4) dm3 mol(-1) cm(-1), which is about 1.5-times greater than that of the alpha-benzilmonoxime extraction based method. The relative standard dev...

A simple spectrophotometric method is described for the determination of ruthenium(III) using 4 benzylideneamino -3mercapto -6methyl 1, 2, 4 triazine (4H) -5one as the colour developing reagent . Accurate and reproducible results were obtained for 6-18 ppm of Ru(III) . The composition of the complex was studied by Job’s method of continous variation and mole ratio method . Results from both the...

an extraction-spectrophotometric method for the determination of trace amounts of ammonium ion is described. ammonium ion is effectively extracted as a neutral ternary complex nh . db 18c6. calmagite at ph 3.0 into chloroform, followed by spectrophotometric determination at =48 5 nm. molar absorptivity of the ternary complex at this wavelength is 1.08 10 mol cm . beer's law is obeyed over ...

a simple and sensitive extraction-spectrophotometric method for rapid and accurate determination of benzocaine in pure and dosage forms was developed. benzocaine was effectively extracted as a 1:1 ion pair complex with dicyclohexyl-18-crown-6 and calmagite in acidic media into chloroform, followed by spectrophotometric determination at 486 nm. molar absorptivity of the ternary complex at this w...

This experiment was carried out to explore the relationship between the absorbance and concentration of colored solutions. After determining the λmax was 635 nm for CuSO4, the absorbance of six solutions of CuSO4, ranging from 0.00 to 0.50 M, was found using a colorimeter. Graphical analysis revealed that the relationship between absorbance and concentration was directly proportional with a mol...

Established methods for determining the serum uric acid concentration are colorimetric, enzymatic, or combination of the two. An alternative method, based on the affinity of purines for polyacrylamide resin, has been developed. Uric acid, more strongly adsorbed than other major serum constituents, elutes later (with phosphate buffer, pH 7) from a poly. acrylamide column. The separated serum uri...