Determination of cholesterol with special reference to the use of p-toluene-sulfonic acid.

NTIL RECENT TIMES the methods for the determination of serum sterol have been difficult and time-consuming. As a result, the rmance of this analysis in hospital laboratories has often pred serious problems. It has been our aim to select a relatively and simple method, yet one with a practical degree of accuracy. reliminary investigation of a number of procedures for the detertion of cholesterol indicated that the Pearson, Stern, and Mcck** method (1) might fill the requirements mentioned above. this method a direct analysis of cholesterol in serum is made ut prior extraction or purification. Glacial acetic acid, pnesulfonic acid solution, and acetic anhydride are added directly serum in the order named, followed by concentrated sulfuric acid. analysis is carried out in a test tube in a relatively short period time and with no manipulations. In a direct method such as this possible effects of interfering substances must be considered. It been reported that when color is developed in the presence of m proteins the values obtained for cholesterol are approximately per cent too low (2). Biirubin is a source of error in the detertion of cholesterol by methods based on the Liebermann-