Quantitative determination of the major 3-hydroxy bile acids in biological material after thin-layer chromatographic separation

1970 ◽  
Vol 28 (3) ◽  
pp. 495-504 ◽  
Author(s):  
Arne Bruusgaard
Keyword(s):  
Thin Layer ◽  
Quantitative Determination ◽  
Bile Acids ◽  
Chromatographic Separation ◽  
Biological Material

Determination of Saccharin in Biological Materials by Gas-Liquid Chromatography

1971 ◽  
Vol 54 (5) ◽  
pp. 1140-1145
Author(s):  
Robert J Daun
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
Quantitative Determination ◽  
Methyl Iodide ◽  
Chromatographic Separation ◽  
Gas Liquid Chromatography ◽  
Ionization Detector ◽  
Animal Tissues ◽  
Flame Ionization

Abstract A method is described for the quantitative determination of saccharin in urine, feces, blood, and animal tissues. The saccharin is extracted with diethyl ether and methylated with methyl iodide to provide a volatile derivative for gas-liquid chromatography. Higher levels, as found in urine and feces, are determined with a flame ionization detector and lower levels, as in blood and tissues, are analyzed with an electron capture detector after a thin layer chromatographic separation.

Spectrodensitometric Determination of Chloramine-T in Ice Cream

1978 ◽  
Vol 61 (6) ◽  
pp. 1415-1418
Author(s):  
Paul R Beljaars ◽  
Theo M M Rondags
Keyword(s):  
Detection Limit ◽  
Thin Layer ◽  
Quantitative Determination ◽  
Chromatographic Separation ◽  
Ice Cream ◽  
Average Recovery ◽  
Scanning Procedure ◽  
Chloramine T ◽  
Whipped Cream

Abstract A spectrodensitometric method has been developed for the quantitative determination of chloramine-T (N-chloro-Ar-sodium-p-toluenesulfonamide) in ice cream. Chloramine-T is extracted and converted into p-toluenesulfonamide (p-TSA) followed by thin layer chromatographic separation of concentrated extracts on silica gel and quantitation of the p-TSA spots from standards and samples by direct scanning with a reflectance densitometer at 228 nm. A linear relationship was obtained between recorded peak area and concentration for 0.5–7.0 μg p-TSA/spot. The reproducibility of the complete method was 2.87% (n = 9 determinations). The detection limit of the scanning procedure was 0.5 μg p-TSA/spot, corresponding to a concentration of 4 mg chloramine-T/kg sample. The average recovery was 88±3% (P = 95%) for 10 ice cream samples spiked with chloramine-T at levels ranging from 10 to 55 mg/kg. The described method was used to assay 146 commercial ice cream and whipped cream samples for chloramine-T.

Thin Layer Chromatographic Separation and Spectrophotofluorometric Determination of Thiabendazole Residues on and in Citrus

1972 ◽  
Vol 55 (6) ◽  
pp. 1239-1244
Author(s):  
S M Norman ◽  
D C Fouse ◽  
C C Craft
Keyword(s):  
Thin Layer ◽  
Quantitative Determination ◽  
Ethyl Acetate ◽  
Chromatographic Separation ◽  
Basic Solution ◽  
Citrus Fruits ◽  
Cattle Feed ◽  
Citrus Pulp ◽  
Significant Difference

Abstract A thin layer chromatographic (TLC)-spectrophotofluorometric method was developed for quantitative determination of thiabendazole on and in citrus. Whole citrus fruits are surface stripped with ethyl acetate and a concentrated aliquot is separated by TLC. Wholefruit blends, juice, oil, and dried citrus pulp cattle feed are extracted with ethyl acetate, partitioned into 0.1N HC1, and then partitioned into ethyl acetate-chloroform from an aqueous basic solution prior to TLC. Thiabendazole is eluted from the chromatogram with acidified methanol and the intensity of fluorescence is compared to standards similarly chromatographed and measured. The method is accurate in determining thiabendazole content ranging from 0.2 to 6 ppm. Recoveries of thiabendazole from fortified samples were 95–99% for surface strippings and 70–91% for rind and pulp extractives. No significant difference was found between residue values determined by the TLC method and by the Merck method. TLC eliminates citrus constituents which occasionally interfere with the Merck method.

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%.

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