Studies on the Quantitative Analysis of Some Poisons by Means of the Thin-Layer Chromatography Part3. Investigation for the Effect of pH, Solvents, and Shaking Times upon the Extraction of Hyponotics from Urine

First of all, the known amounts of α-bromoisovarerylurea, barbital, and 2-methyl-3-0-tolylquinazolone were added to humane urine, respectively and the recoverise of these hyponotics from the urine were calculated by using the algebraic determination of thin-layer chromatography. Thus, various conditions for the extraction of hyponotics such as solvents, pH, the numbers of extraction, and each shaking time were studied. The results obtained were summarized as follows. 1) Ether, ethylene dichloride, and choroform were recognized to be suitable as solvents for the extraction of these hyponotics among the five organic solvents used. 2) The highest recoveries of α-bromoisovarerylurea, barbital, and 2-methyl-3-0-tolylquinazolone were given, respectively, at PH 5.0, 6.0 and 4.0.Through all these hyponotics the diffrences of recoveries at each pH value, lower than pH 6.0 were slightly little, but the recovery at pH 8.0 was found cosiderably lower compared with those in acidic pH region. 3) Barbital, and 2-methyl-3-0-tolylquinazolone were almost completely recovered by repeating the extraction three times. In spite of repeating the extraction three times the recovery of α-bromoisovarerylurea was only 74% of total weight, whereas it could be increased up to 96% by the addition ot sodium chloride to urine. 4) It was found that the shaking times required to reach the distribution-equilibrium between ethylene dichloride and urine were fairly of difference among the hyponotics so far tested.