EINE CHEMISCHE METHODE ZUR BESTIMMUNG VON 16-EPI-ÖSTRIOL IM URIN DES MENSCHEN

1963 ◽  
Vol 44 (1) ◽  
pp. 47-66 ◽  
Author(s):  
W. Nocke ◽  
H. Breuer
Keyword(s):  
Melting Point ◽  
Phosphoric Acid ◽  
Aqueous Alkali ◽  
Percentage Error ◽  
Organic Layer ◽  
Maximum Percentage ◽  
Chemical Determination ◽  
Routine Assay ◽  
Hydrolysis Of

ABSTRACT A method for the chemical determination of 16-epi-oestriol in the urine of nonpregnant women with a qualitative sensitivity of less than 0.5 μg/24 h is described. The separation of 16-epi-oestriol and oestriol is accomplished by converting 16-epi-oestriol into its acetonide, a reaction which is stereoselective for cis-glycols and therefore not undergone by oestriol as a trans-glycol. Following partition between chloroform and aqueous alkali, the acetonide of 16-epi-oestriol is completely separated with the organic layer whereas oestriol as a strong phenol remains in the alkaline phase. 16-epi-oestriol is chromatographed on alumina as the acetonide and determined as a Kober chromogen. This procedure can easily be incorporated into the method of Brown et al. (1957 b) thus making possible the simultaneous routine assay of oestradiol-17β, oestrone, oestriol and 16-epi-oestriol from one sample of urine. The specificity of the method was established by separation of 16-epi-oestriol from nonpregnancy urine as the acetonide, hydrolysis of the acetonide by phosphoric acid, isolation of the free compound by microsublimation and identification by micro melting point, colour reactions and chromatography. The accuracy of the method is given by a mean recovery of 64% for pure crystalline 16-epi-oestriol when added to hydrolysed urine in 5–10 μg amounts. The precision is given by s = 0.24 μg/24 h. For the duplicate determination of 16-epi-oestriol the qualitative sensitivity is 0.44 μg/24 h, the maximum percentage error being ± 100% The quantitative sensitivity (±25% error) is 1.7 μg/24 h.

scholarly journals Extractive Spectrophotometric Determination of Malathion in Environmental Samples Using Gention Violet

2005 ◽  
Vol 2 (3) ◽  
pp. 187-192 ◽  
Author(s):  
K. M. Reddy ◽  
K. Suvardhan ◽  
K. Suresh Kumar ◽  
D. Rekha ◽  
P. Chiranjeevi
Keyword(s):  
Spectrophotometric Method ◽  
Alkaline Hydrolysis ◽  
Environmental Samples ◽  
Sodium Ethoxide ◽  
Ion Pair ◽  
Soil Samples ◽  
Organic Layer ◽  
Cationic Dye ◽  
Hydrolysis Of

A new simple and selective spectrophotometric method is developed for the determination of malathion by using Gention violet is described. The method was based on the alkaline hydrolysis of malathion in presence of sodium ethoxide to form sodium dimethyl dithiophosphate (Na-DMDTP). The Na-DMDTP was formed as an ion-pair complex with cationic dye, gention violet. The ion-pair complex was extracted into chloroform. The color of the organic layer was measured at 587 nm. The method was applied to the determination of malathion residues in water, grain and soil samples

Automated Chemical Determination of Methionine

1974 ◽  
Vol 57 (3) ◽  
pp. 682-688
Author(s):  
Charles W Gehrke ◽  
Terry E Neuner
Keyword(s):  
Amino Acid ◽  
Standard Deviation ◽  
Ion Exchange ◽  
Automated System ◽  
Automated Method ◽  
Relative Standard ◽  
Chemical Determination ◽  
Sample Recovery ◽  
Hydrolysis Of

Abstract A rapid, accurate, and precise spectrophotometry method, based on the nitroprussidemethionine color reaction, has been developed for the determination of methionine in soybeans, mungbeans, and corn. Amino acid interference was eliminated by partial enzymatic hydrolysis of samples for 4 hr at 50 °C with papain; the samples were analyzed by an automated system. Precision and accuracy were determined by repeated independent analyses of 13 samples of corn, mungbeans, and soybeans; the data were compared to independent classical ion exchange amino acid results. The range for each set of samples varied from 0.02 to 0.04 w/w% methionine. The per cent recovery for 12 of the 13 samples compared to those from ion exchange ranged from 95.2 to 107.1% with an average of 100.2%. The standard deviation varied from 0.01 to 0.02, and the per cent relative standard deviation from 11.8% for a 0.16 w/w% sample to 2.5% for a 0.42 w/w% sample. Recovery of added methionine from corn samples ranged from 92.7 to 102.0% (96.8% average) ; from soybeans 95.0 to 112.0% (101.9% average); and from mungbeans 91.3 to 102.0% (95.8% average). A reliable automated method has been developed which is applicable to different types of biological substances; 20 samples/hr can be analyzed.

scholarly journals Extractive Spectrophotometric determination of Dimethoate in Environmental Samples with Azure-B

2005 ◽  
Vol 2 (3) ◽  
pp. 193-198
Author(s):  
K. M. Reddy ◽  
P. Chiranjeevi
Keyword(s):  
Spectrophotometric Method ◽  
Environmental Samples ◽  
Sodium Ethoxide ◽  
Ion Pair ◽  
Soil Samples ◽  
Organic Layer ◽  
Cationic Dye ◽  
Azure B ◽  
Hydrolysis Of

A new simple and selective spectrophotometric method is developed for the determination of dimethoate by using Azure-B is described. The method was based on the alkaline hydrolysis of dimethoate in presence of sodium ethoxide to form sodium dimethyl dithiophosphate (Na-DMDTP). The Na-DMDTP was formed as an ion-pair complex with cationic dye, azure-B. The ion-pair complex was extracted into chloroform. The color of the organic layer was measured at 535 nm. The method was applied to the determination of dimethoate residues in water, grain and soil samples.

Chemical Determination of Diethylstilbestrol Residues in the Tissues of Treated Chickens

1963 ◽  
Vol 46 (3) ◽  
pp. 471-479 ◽  
Author(s):  
Ernest J Umberger ◽  
Daniel Banes ◽  
Frieda M Kunze ◽  
Sylvia H Colson
Keyword(s):  
Fluorescence Spectra ◽  
Alcohol Solution ◽  
Uterine Weight ◽  
Chemical Methods ◽  
Edible Tissues ◽  
Chemical Determination ◽  
Colored Product ◽  
Weight Method ◽  
Hydrolysis Of

Abstract Bioassays based on the oral mouse uterine weight method have demonstrated the presence of estrogenic residues due to diethylstilbestrol in the edible tissues of chickens implanted with the drug. Chemical methods have now been developed which demonstrate conclusively that the estrogenic residues are diethylstilbestrol. Alcoholic extracts of the tissues are hydrolyzed with acid and carried through several extraction procedures. The residues are irradiated with ultraviolet light in a buffered alcohol solution, giving a yellow product which is measured colorimetrically. The colored product can be further converted to a colorless phenanthrene derivative that can be measured fluorometrically. The fluorophor gives characteristic activation and fluorescence spectra which can be used for identification. The diethylstilbestrol can also be identified by paper chromatography. Hydrolysis of the extracts with betaglucuronidase frees only a portion of the diethylstilbestrol in liver tissue.

DETERMINATION OF MICRO-AMOUNTS OF 5β-PREGNAN-3α-OL-20-ONE IN URINE USING INFRARED-SPECTROMETRY

1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen
Keyword(s):  
Infrared Spectrum ◽  
Quantitative Determination ◽  
Acid Hydrolysis ◽  
Chromatographic Separation ◽  
Pure Form ◽  
Infrared Spectrometry ◽  
Hydrolysis Of

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.

CHEMICAL DETERMINATION OF OESTROGENS IN THE URINE OF WOMEN WITH CANCER OF THE BREAST

1957 ◽  
Vol 24 (3_Suppl) ◽  
pp. S319-S323 ◽  
Author(s):  
Heinz Breuer ◽  
Wolfgang Nocke
Keyword(s):  
Chemical Determination

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

Determination of δ-hexadecansultone in sodium α-olefinesulphonates and liquid detergents using gas chromatography-mass spectrometry (GC/MS)

2019 ◽  
Vol 85 (7) ◽  
pp. 16-21
Author(s):  
Liliya R. Mubarakova ◽  
German K. Budnikov
Keyword(s):  
Multicomponent Mixture ◽  
Operating Mode ◽  
Complete Separation ◽  
Gas Chromatography Mass Spectrometry ◽  
Liquid Detergent ◽  
Cyclic Esters ◽  
Alcohol Water ◽  
Household Chemicals ◽  
Hydrolysis Of

Sultones are cyclic esters of hydroxysulfonic acids, which are formed in the process of sulfonation of α-olefins with sulfur trioxide gas. More stable sultones may be present in the final product — an anionic surfactant — sodium α-olefin sulfonate (AOC-Na). AOC-Na is widely used in the production of household chemicals and cosmetic products, including liquid dishwashing detergents. Sultones are strong skin sensitizers, their level in AOC-Na should be strictly controlled and not exceed 5 ppm. Operational and strict control of the sultone content upon AOC-Na production allows timely adjustment at the stage of hydrolysis, which leads to a more complete disclosure of the sultone cycle with the formation of the corresponding olefin sulfonates and hydroxyalkanesulfonates. We propose a method for determining δ-hexadecansultone in liquid dishwashing detergents and sodium α-olefinsulfonates obtained on the basis of α-olefins of C14 – C16 fractions using GC/MS, which provides shortening of sample preparation and keeps the sensitivity with a detection limit of 0.02 mg/kg. The effect of various weakly polar and non-polar organic solvents used for Sultone extraction from AOC-Na and liquid detergent on liquid extraction based on the dispersion of the extractant in an alcohol/water phase is studied. When selecting the solvent we have shown that the use of diethyl ether provided the best extraction of the analyte. Determination of the analyte extraction recovery was performed using the reaction of hydrolysis of the extracted mixture. We specified the operating mode of the device which provided complete separation of the components of the analyzed compounds including the samples of liquid detergent for dishes being a multicomponent mixture of complex composition.

Sign in / Sign up

Export Citation Format

Share Document