Results 221 to 230 of about 48,569 (262)
Some of the next articles are maybe not open access.
Spectrophotometric and titrimetric determination of catecholamines
Talanta, 1987Ammonium metavanadate is used to determine adrenaline, noradrenaline, isopropylnoradrenaline and methyldopa by titrimetric and photometric procedures. Oxidation of these catecholamines produces aminochrome derivatives which can be measured spectrophotometrically at 485 nm.
openaire +2 more sources
A spectrophotometric determination of trypsin and chymotrypsin
Biochimica et Biophysica Acta, 1955Abstract A sensitive spectrophotometric assay for trypsin and chymotrypsin using synthetic substrates has been described.
G W, SCHWERT, Y, TAKENAKA
openaire +2 more sources
Spectrophotometric determination of traces of antimony
Talanta, 1971Antimony(III) is extracted into carbon tetrachloride from 4M sulphuric acid that is 0.05M in potassium iodide. 8-Mercaptoquinoline and acetone are added to the organic extract and the absorbance of the complex formed is measured at 390 nm. Repeating the extraction procedure greatly increases the selectivity of the method.
openaire +2 more sources
Spectrophotometric Determination of Free Silica
American Industrial Hygiene Association Journal, 1973The quantitative determination of free silica by spectrophotometric procedure is described, from the initial treatment of samples in phosphoric acid to remove silicates through the separation and quantitation of free silica. The method can be used with biological materials as well as with airborne participates.
D V, Sweet, F R, Wolowicz, J V, Crable
openaire +2 more sources
Spectrophotometric determination of silicon in ferrophosphorus
Talanta, 1975A method is described for the spectrophotometric determination of 0-4% silicon in ferrophosphorus, following fusion with sodium peroxide in a zirconium crucible. Silicomolybdic acid is formed with sodium molybdate. The acidity is increased to 2N and the solution stood for 10 min to destroy phosphomolybdic and arsenomolybdic acids.
K A, Brooking, C B, Belcher
openaire +2 more sources
Spectrophotometric methods for the determination of manganese
Talanta, 1990A comprehensive and critical review of the available spectrophotometric methods for the determination of manganese is presented. Details are given of a wide range of direct colour-forming reactions of manganese with organic ligands, which have been claimed to be of use in analysis for the metal. The use of the very sensitive kinetic methods of analysis
Chiswell, Barry +2 more
openaire +4 more sources
Spectrophotometric determination of aluminium by morin
Talanta, 1995A direct spectrophotometric method for the determination of aluminium with morin has been developed. Morin reacts in slightly acidic 50% ethanolic media (0.0001-0.0015 M H(2)SO(4)) with Al to give a deep-yellow chelate which has an absorption maximum at 421 nm. The average molar absorptivity and Sandell's sensitivity were found to be 5.3 x 10(3) l mol(-
M J, Ahmed, J, Hossan
openaire +2 more sources
Spectrophotometric Determination of Protein Concentration
Current Protocols in Protein Science, 2003AbstractThe concentration of a purified protein in solution is most conveniently and accurately measured using absorbance spectroscopy. The absorbance,A, is a linear function of the molar concentration,C, according to the Beer‐Lambert law:A= ɛ ×l×c, where e is the molar absorption coefficient andlis the cell path length.
Gerald R, Grimsley, C Nick, Pace
openaire +2 more sources
Spectrophotometric determination of molybdenum(VI)
Talanta, 1974Molybdenum(IV) gives a red colour with ammonium thiocyanate in 5-8M hydrochloric acid medium, the Sandell sensitivity index being 0.018 ppm Mo(VI)/cm(2). Molybdenum(VI) in 4-7M hydrochloric acid medium forms a red complex with ethyl xanthate and ammonium thiocyanate and this can be extracted into acetophenone. Beer's law is obeyed over the range of 1.2-
M K, Arunachalam, M K, Kumaran
openaire +2 more sources
The spectrophotometric determination of riboflavine in urine
The Analyst, 1969A simple spectrophotometric method for the determination of riboflavine in urine is described. The urine, after treatment with zinc acetate and formaldehyde, is passed through a small column of large particle-size talc on which the riboflavine is selectively and quantitatively adsorbed.
openaire +2 more sources