A colorimetric procedure for the determination of triose phosphate and fructose-1,6-diphosphate in presence of other sugars

1960 ◽  
Vol 39 (1) ◽  
pp. 144-147 ◽  
Author(s):  
Zacharias Dische ◽  
Edith Landsberg
Keyword(s):  
Triose Phosphate ◽  
Colorimetric Procedure

On the three-dimensional structure and catalytic mechanism of triose phosphate isomerase

1981 ◽  
Vol 293 (1063) ◽  
pp. 159-171 ◽  
Keyword(s):  
Catalytic Mechanism ◽  
Polypeptide Chain ◽  
Three Dimensional ◽  
Triose Phosphate Isomerase ◽  
Dimensional Structure ◽  
Dihydroxyacetone Phosphate ◽  
Triose Phosphate ◽  
Independent Determination ◽  
Chicken Muscle

Triose phosphate isomerase is a dimeric enzyme of molecular mass 56000 which catalyses the interconversion of dihydroxyacetone phosphate (DHAP) and D-glyceraldehyde-3-phosphate. The crystal structure of the enzyme from chicken muscle has been determined at a resolution of 2.5 A, and an independent determination of the structure of the yeast enzyme has just been completed at 3 A resolution. The conformation of the polypeptide chain is essentially identical in the two structures, and consists of an inner cylinder of eight strands of parallel |3-pleated sheet, with mostly helical segments connecting each strand. The active site is a pocket containing glutamic acid 165, which is believed to act as a base in the reaction. Crystallographic studies of the binding of DHAP to both the chicken and the yeast enzymes reveal a common mode of binding and suggest a mechanism for catalysis involving polarization of the substrate carbonyl group.

THE DETERMINATION OF PHOSPHOLIPID PHOSPHORUS

1949 ◽  
Vol 27e (3) ◽  
pp. 159-163 ◽  
Author(s):  
J. M. R. Beveridge ◽  
S. E. Johnson
Keyword(s):  
Color Stability ◽  
Accurate Method ◽  
Inorganic Phosphorus ◽  
Strict Adherence ◽  
Beer's Law ◽  
Beer’S Law ◽  
Excellent Color ◽  
Colorimetric Procedure

A simple accurate method for the determination of phospholipid phosphorus is described. Conditions for the digestion of phospholipid have been developed permitting the utilization of a colorimetric procedure for inorganic phosphorus that is characterized by excellent color stability and strict adherence to Beer's law over a range of 0 to 65 μgm. of phosphorus.

scholarly journals Determination of Uric Acid

1967 ◽  
Vol 13 (1) ◽  
pp. 12-18 ◽  
Author(s):  
H Harold Nishi
Keyword(s):  
Uric Acid ◽  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Serum Sample ◽  
Colorimetric Procedure ◽  
Sodium Hydroxide Treatment

Abstract The Archibald colorimetric procedure for determination of uric acid has been adapted for automation. The major differences from the original manual procedure after sodium hydroxide treatment of the serum sample are neutralization with hydrochloric acid and dialysis of the serum instead of precipitation to remove protein. At the rate of 40 samples per hour, the automated procedure shows good correlation with the manual procedure.

Determination of Iron in Serum or Plasma by Atomic Absorption Spectrophotometry

1966 ◽  
Vol 12 (6) ◽  
pp. 338-349 ◽  
Author(s):  
Denis O Rodgerson ◽  
Ray E Helfer
Keyword(s):  
Atomic Absorption ◽  
Atomic Absorption Spectrophotometry ◽  
Mean Value ◽  
Normal Range ◽  
Single Beam ◽  
Average Percentage ◽  
Absorption Spectrophotometry ◽  
Colorimetric Procedure ◽  
Measured Volume

Abstract The determination of serum iron has been shown to be feasible by the use of a modified single-beam atomic absorption spectrophotometer. The effect of interfering substances is eliminated by the use of standards prepared in physiological concentrations of protein. Average percentage recovery of added iron was 97.9 with an over-all coefficient of variation of 1.6%. Disparities between samples due to the effect of unequal viscosities and flow rates were overcome by the integration of the record curve generated by a measured volume of sample. Comparison between the method presented and a colorimetric procedure gave a higher mean value and normal range for plasma quantitated by atomic absorption spectrophotometry.

Serum Propylthiouracil: Determination by a Direct Colorimetric Procedure

1972 ◽  
Vol 18 (11) ◽  
pp. 1373-1375 ◽  
Author(s):  
Charles R Ratliff ◽  
Paul F Gilliland ◽  
Frank F Hall
Keyword(s):  
Filter Paper ◽  
Colorimetric Method ◽  
Control Sample ◽  
Chloroform Solution ◽  
Soluble Compound ◽  
Aqueous Layer ◽  
Free Serum ◽  
Drug Free ◽  
Colorimetric Procedure

Abstract A direct colorimetric method is described for the determination of propylthiouracil in serum, which is based on reaction of the drug at pH 8.0 with 2,6-dichloroquinone-chloroimide to produce a colored chloroform-soluble compound. After isolation from the aqueous layer with phase-separating filter paper, the chloroform solution is read against a chloroform blank at 435 nm. Propylthiouracil added to drug-free serum serves as a control sample. The method obeys Beer's law up to a concentration of at least 10 mg/liter.

Colorimetric Determination of Procaine Penicillin in Mixed Feeds

1965 ◽  
Vol 48 (4) ◽  
pp. 702-704
Author(s):  
Loyal R Stone
Keyword(s):  
Chemotherapeutic Agents ◽  
Colorimetric Determination ◽  
Procaine Penicillin ◽  
Acid Reagent ◽  
Mixed Feeds ◽  
Colorimetric Procedure

Abstract Procaine penicillin is determined by a rapid colorimetric procedure based on conversion of penicillin to penicillamine which turns blue with arsenomolybdic acid reagent. The presence of other antibiotics and chemotherapeutic agents in the feed does not interfere. The method is suitable over the range 10–100 g procaine penicillin per ton of feed.

Determination of uric acid on continuous-flow (AutoAnalyzer II and SMA) systems with a uricase/phenol/4-aminophenazone color test.

1978 ◽  
Vol 24 (2) ◽  
pp. 250-255 ◽  
Author(s):  
S Klose ◽  
M Stoltz ◽  
E Munz ◽  
R Portenhauser
Keyword(s):  
Uric Acid ◽  
Continuous Flow ◽  
Ascorbate Oxidase ◽  
Routine Test ◽  
Color Test ◽  
Clinical Laboratories ◽  
A Minor ◽  
Red Dye ◽  
Colorimetric Procedure

Abstract This report describes a new specific colorimetric procedure for uric acid assay with AutoAnalyzer II and SMA (Technicon) systems, made specific by the application of uricase. Hydrogen preroxide, formed in this reaction, effects the oxidative coupling of 4-aminophenazone and 2,4-dichlorophenol under the catalytic influence of peroxidase. The red dye formed is measured at 505 or 520 nm. A sample blank measurement is not necessary, and the reagents show very good stability. The test shows linearity up to 714 mumol of uric acid per liter. Results of thie method correlate very well with those by the uricase-ultraviolet and uricase--catalase methods. There is no interference by hemoglobin, bilirubin, lipemia, and various drugs, except a minor interference by alpha-methyldopa. Interference from ascorbate is eliminated by ascorbate oxidase. This method can be regarded as a considerably improved routine test for uric acid on continuous-flow systems in clinical laboratories as compared with the commonly used phosphotungstate method.

Fluorometric Determination of Methyl Anthranilate in Concord Grape Juice

1976 ◽  
Vol 59 (2) ◽  
pp. 269-272
Author(s):  
Donald J Casimir ◽  
James C Moyer ◽  
Leonard R Mattick
Keyword(s):  
Correlation Coefficient ◽  
Grape Juice ◽  
Methyl Anthranilate ◽  
Fluorometric Method ◽  
Fluorometric Determination ◽  
Juice Concentrate ◽  
Concord Grape ◽  
Colorimetric Procedure

Abstract A method is described for the determination of methyl anthranilate in Concord grape products. A sample of juice, concentrate, pulp, or essence is steam distilled in a micro-Kjeldahl unit and the fluorescence of the distillate collected in pH 7 buffer is measured directly with a fluorometer. The method is rapid and sensitive to 0.1 ppm methyl anthranilate. A correlation coefficient of 0.988 was found between the AOAC colorimetric procedure and the fluorometric method.

Determination of Trimethylamine Nitrogen in Extracts and in Volatile Fractions of Fish

1965 ◽  
Vol 48 (4) ◽  
pp. 731-735
Author(s):  
Sammie Bethea ◽  
Fred Hillig
Keyword(s):  
Colorimetric Method ◽  
Accurate Estimate ◽  
Colorimetric Procedure

Abstract Dyer’s colorimetric procedure was applied to the determination of trimethylamine nitrogen (TMA-N) in distillates from frozen cod and frozen haddock. Studies show that a more accurate estimate of the TMA-N contained in fish is obtained when this colorimetric method is applied to the distillates rather than to the extract. The method is also shortened by the elimination of one distillation, two oxidations, and two titrations.

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