Chemical analysis of gallstones. (I) Extraction and quantification of gallstone components
Mukaihara, S.
Nihon Geka Hokan. Archiv für Japanische Chirurgie 50(1): 190-201
1981
ISSN/ISBN: 0003-9152 PMID: 7283610 Document Number: 175011
A microchemical technique for the analysis of is transferred to a 10 ml glass-stoppered centrifuge tube, mixed with solvents and stirred with an ultrasonic stirrer. The tube is centrifuged at 4000 rpm for 15 min. An aliquot of the supernatant is placed in a small test tube, the excess supernatant is aspirated and the residue is dried. Stepwise solvent extraction consists in sequence of: petroleum ether 10 ml; 1 N-hydrochloric acid 10 ml; petroleum ether 10 ml; and dimethyl sulfoxide (DMSO) 10 ml. Each extraction procedure takes < 20 min. An aliquot of the petroleum ether extract is used for the colorimetric determination of cholesterol by Zak-Henly's method and of fatty acids by Itaya-Ui's method. An aliquot of the HCl extract is used for the colorimetric determination of Ca by the OCPC method and of Pi by Goldenberg's method. An aliquot of the DMSO extract is used for the colorimetric determination of bilirubin by the oxidation method. Bilirubin and biliverdin in gallstone are directly extracted with DMSO acidified with 1% volume of 1 N-HCl. Bilirubin is measured by Malloy-Evelyn's method, and both bilirubin and biliverdin are measured by the bilirubin oxidation method. Biliverdin is determined from the difference between the values of the 2 methods. The recoveries of each gallstone component range from 94-106% in these colorimetric determinations.