A METHOD FOR THE DETERMINATION OF VERY SMALL AMOUNTS OF OESTRONE IN HUMAN URINE

1960 ◽  
Vol 20 (4) ◽  
pp. 331-338 ◽  
Author(s):  
J. B. BROWN ◽  
H. A. F. BLAIR
Keyword(s):  
Sensitivity And Specificity ◽  
Methyl Ether ◽  
Human Urine ◽  
New Method ◽  
Enzymic Hydrolysis ◽  
Purification Step ◽  
Acidic Fraction ◽  
Hydrolysis Of ◽  
Alkaline Carbonate

SUMMARY A purification step involving separation of the ketonic fraction through the Girard complex has been incorporated in an earlier method for estimating urinary oestrogens. The new method, which measures oestrone only, involves acid or enzymic hydrolysis of the urine, extraction with ether, removal of the acidic fraction with alkaline carbonate solution, evaporation of the ether, separation of the ketonic fraction through the Girard complex, saponification, methylation, and chromatography on alumina columns. The oestrone methyl ether present in the final extract is measured by a semi-micro modification of the Kober reaction, which, with the larger volume of urine processed, increases the sensitivity of the estimation ninefold. This increase in sensitivity is made possible by the purification achieved in the new method, and fractions of 1 μg oestrone/24 hr urine can be measured. The reliability of the new method has been investigated and data concerning its accuracy, precision, sensitivity and specificity are presented. By comparison with the new method, the earlier method gives overestimates of approx. 0.9 μg oestrone/24 hr urine.

PREGNANETRIOL IN URINE: DETERMINATION AS A 17-KETOGENIC STEROID

1959 ◽  
Vol XXXII (IV) ◽  
pp. 596-605 ◽  
Author(s):  
R. Morris
Keyword(s):  
Congenital Adrenal Hyperplasia ◽  
Silica Gel ◽  
New Method ◽  
Adrenal Hyperplasia ◽  
Enzymic Hydrolysis ◽  
Normal Individuals ◽  
Hydrolysis Of

ABSTRACT A new method has been described for the determination of pregnanetriol in urine. It depends on the oxidation of pregnanetriol glucuronide to aetiocholanolone and its measurement as a Zimmermann chromogen after chromatography on silica gel. The method was applied to the urine from normal individuals and patients with congenital adrenal hyperplasia and the results were compared with a method using enzymic hydrolysis of the steroid conjugate.

Brief technical note A new method for the determination of 6-beta-OH-cortisol in human urine

1981 ◽  
Vol 114 (1) ◽  
pp. 107-110 ◽  
Author(s):  
M. Lodovici ◽  
P. Dolara ◽  
P. Bavazzano ◽  
A. Colzi ◽  
V. Pistolesi
Keyword(s):  
Human Urine ◽  
Technical Note ◽  
New Method

THE DETERMINATION OF SMALL QUANTITIES OF URINARY OESTRONE, OESTRADIOL-17β AND OESTRIOL USING ITTRICH'S EXTRACTION METHOD

1961 ◽  
Vol 22 (1) ◽  
pp. 47-58 ◽  
Author(s):  
R. A. A. SALOKANGAS ◽  
R. D. BULBROOK
Keyword(s):  
Extraction Method ◽  
New Method ◽  
Urine Specimen ◽  
Purification Step ◽  
Reasonable Degree ◽  
Accuracy And Precision ◽  
Method Show

SUMMARY 1. The purification step described by Ittrich (1958) has been incorporated in the method of Brown, Bulbrook & Greenwood (1957b) for estimating urinary oestrogens. 2. When the Kober colours given by urinary oestrone, oestradiol-17β and oestriol are extracted with tetrachloroethane containing p-nitrophenol, the decrease in the absorption due to impurities is such that the Kober reaction can be scaled down and micro-cells used in the measurement of the final colours. 3. Amounts of urinary oestrogens as low as 0·5 μg./24 hr. specimen can be measured with a reasonable degree of accuracy and precision. 4. The results with the new method show that the method of Brown et al. (1957b) gives over-estimates of approx. 1 μg. oestrone and 1 μg. oestriol/24 hr. urine specimen when used for the estimation of urinary oestrogens of low titre.

scholarly journals The hydrolysis of glycosyl fluorides by glycosidases. Determination of the anomeric configuration of the products of glycosidase action

1971 ◽  
Vol 123 (4) ◽  
pp. 607-611 ◽  
Author(s):  
J. E. G. Barnett
Keyword(s):  
Glucose Oxidase ◽  
Galactose Oxidase ◽  
Coffee Bean ◽  
Enzymic Hydrolysis ◽  
Initial Product ◽  
Rapid Assay ◽  
Anomeric Configuration ◽  
Ph Stat ◽  
Hydrolysis Of

The enzymic hydrolysis of glycosyl fluorides is conveniently followed by using a pH-stat. Reactions involving glucosyl or galactosyl fluorides can also be followed by using glucose oxidase or galactose oxidase respectively. The pH-stat allows the rapid assay of intestinal α-glucosidase in crude homogenates. Use of glycosyl fluorides as substrates for glycosidases facilitates the polarimetric or g.l.c. determination of the anomeric nature of the initial product of hydrolysis. Hydrolysis by fungal amyloglucosidase proceeds with inversion of configuration whereas that by yeast and rat intestinal α-glucosidase, coffee-bean α-galactosidase and almond emulsin β-glucosidase proceeds with retention of configuration. β-d-Glucopyranosyl azide was not a detectable substrate for almond emulsin β-d-glucosidase.

Etude de la coagulation des eaux par fluorométrie

1975 ◽  
Vol 2 (3) ◽  
pp. 253-261
Author(s):  
Jean-B. Sérodes ◽  
Alain Soucy
Keyword(s):  
Water Treatment ◽  
Low Temperatures ◽  
New Method ◽  
Fluorometric Method ◽  
Aluminum Salts ◽  
Aluminum Ion ◽  
Water Treatment Plants ◽  
Residual Aluminum ◽  
Hydrolysis Of

The use of a fluorometric method for the determination of residual aluminum salts used as coagulants in water treatment has permitted evaluation of the influence of some factors, particularly temperature, on the hydrolysis of these salts. The yield of hydrolysis is lessened by low temperatures and aluminum ion is more sensitive than aluminate ion. This new method is suggested for detecting abnormal working of water treatment plants.

THE DIFFERENTIAL DETERMINATION OF CONJUGATED HYDROXYSKATOLES IN HUMAN URINE

1967 ◽  
Vol 45 (9) ◽  
pp. 1317-1322 ◽  
Author(s):  
M. E. Mahon ◽  
G. L. Mattok
Keyword(s):  
Ethyl Acetate ◽  
Silica Gel ◽  
Human Urine ◽  
Thin Layers ◽  
Enzymic Hydrolysis ◽  
Sulfate Ester ◽  
Normal Controls

A method is described for the separation and estimation of 4-, 5-, 6-, and 7-hydroxyskatole sulfate esters in urine. After extraction from urine, the 5-, 6-, and 7-hydroxyskatole sulfate esters were hydrolyzed by a sulfatase preparation to the corresponding hydroxyskatoles. The 4-isomer was resistant to this enzymic hydrolysis. The hydroxyskatoles were then extracted by ethyl acetate from the hydrolyzate followed by extraction of the 4-sulfate ester by n-butanol. Each fraction was chromatographed on silica gel G thin layers, sprayed with a modified Ehrlich's reagent (p-N,N-bis(2-chloroethyl)aminobenzaldehyde), and the appropriate zones eluted from the chromatogram. The concentrations of each isomer originally present in the urine were estimated from the absorbances of the four eluates at their absorption maxima (ca. 600 mμ). The levels of the four isomeric skatolyl sulfates found in urines from 10 normal controls are given.

A New Method for the Determination of Nitrofurantoin in Urine

1965 ◽  
Vol 11 (10) ◽  
pp. 925-931 ◽  
Author(s):  
John D Conklin ◽  
Richard D Hollifield
Keyword(s):  
Urinary Tract ◽  
Human Urine ◽  
Antibacterial Agent ◽  
New Method ◽  
Direct Extraction ◽  
Standard Curve ◽  
Quantitative Procedure

Abstract Nitrofurantoin is presently used as an antibacterial agent for the urinary tract of both man and animals. A new, quantitative procedure for the determination of this drug in urine consists of direct extraction of the nonionized form of the drug by the use of nitromethane, addition of an alkaline reagent to the extract to produce a visible color, and determination of the nitrofurantoin concentration by spectrophotometry. The method has a sensitivity of 5 mg./L., with recoveries of 99-101% and a standard curve that is linear to 100 mg./L. Results indicate that the method measures nitrofurantoin alone, and not its metabolites, in rat, dog, and human urine.

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