Results 251 to 260 of about 1,703,225 (294)

A spectrophotometric determination of trypsin and chymotrypsin

Biochimica et Biophysica Acta, 1955
Abstract A sensitive spectrophotometric assay for trypsin and chymotrypsin using synthetic substrates has been described.
G W, SCHWERT, Y, TAKENAKA
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Spectrophotometric determination of sukphur dioxide

Environmental Pollution, 1987
Sulphur dioxide, an important industrial gas and air pollutant, is usually estimated using mercury salts. The authors have developed a method in which hazardous mercury salts are avoided. Sulphur dioxide is trapped in aqueous morpholine and mixed with the excess of dichromate solution in acidic medium.
D C, Parashar, V, Raman, M, Singh
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Spectrophotometric determination of beryllium with calcichrome

Talanta, 1981
A method is established for the spectrophotometric determination of small amounts of beryllium as a 1:1 complex with Calcichrome in slightly acidic solution. Beer's law is obeyed over the range 0.05-0.6 ppm Be in the final solution and the apparent molar absorptivity is 9.7 x 10(3) l.mole(-1). cm(-1) at 625 nm.
H, Einaga, H, Ishii
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The spectrophotometric determination of riboflavine in urine

The Analyst, 1969
A 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.
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SPECTROPHOTOMETRIC DETERMINATION OF BENZENE IN ETHANOL

Journal of Clinical Pharmacy and Therapeutics, 1991
A rapid, simple spectrophotometric method for the detection and determination of benzene in ethanol is described. Thus, using 1 cm cuvettes and applying the first and/or the second derivative methods, benzene can be determined in ethanol over the concentration range of 5-25 p.p.m. with a CV% less than 1% and with a detection limit of 2 p.p.m.
M H, Barary, S M, Sabry, A A, Wahbi
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SPECTROPHOTOMETRIC DETERMINATION OF THE FUNGICIDE CAPTAN

Journal of Environmental Science and Health, Part B, 2002
A spectrophotometric method for the determination of the fungicide captan has been developed based on its reaction with thiosemicarbazide. The absorbance was measured at 315 nm. The effects of the proportion of water, thiosemicarbazide concentration, pH and temperature on this reaction was studied to select the best chemical conditions. The calibration
Teresa, Galeano, Agustina, Guiberteau, Nielene M, Mora, Pedro R, Alvarez, Francisco, Salinas   +4 more
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Spectrophotometric determination of hexafluoroarsenate with ferroin

Talanta, 1967
A spectrophotometric method for the hexafluoroarsenate anion is described. The determination involves selective extraction of the tris(1,10-phenanthroline)iron(II) salt of the anion into n-butyronitrile, followed by measurement of the absorbance of the organic layer.
V S, Archer, F G, Doolittle
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Spectrophotometric determination of pyridoxine hydrochloride

The Analyst, 1987
A spectrophotometric method is described for the determination of pyridoxine hydrochloride based on an oxidative coupling reaction with 4-aminoantipyrine in the presence of ammonium persulphate. The stable yellow colour obtained is measured spectrophotometrically at 420 nm.
V, Nirmalchandar, R, Viswanathan, N, Balasubramanian   +2 more
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Spectrophotometric determination of chlordiazepoxide and nitrazepam

Talanta, 1988
The use of ethyl acetoacetate in the spectrophotometric determination of chlordiazepoxide and nitrazepam has been investigated. The procedure is based on coupling the diazotized drugs with ethyl acetoacetate, which possesses an active methylene group. The products have absorption maxima at 408 and 482 nm and apparent molar absorptivities of 2.74 x 10(4)
M I, Walash, M, Rizk, A, El-Brashy
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Spectrophotometric methods for the determination of tolnaftate

Talanta, 1993
Two simple and sensitive visible spectrophotometric methods (methods A and B) for the determination of tolnaftate in bulk samples and formulations are described. Method A (lambda(max) 490 nm) involves the reaction of tolnaftate with 2,6-dichloroquinone-4-chlorimide (DCQC: Gibb's reagent), while method B (lambda(max) 530 nm) is based on a similar ...
C S, Sastry, B S, Sastry, J V, Rao, R R, Krishna   +3 more
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