けい光法によるカルバゾール中の微量アントラセンの迅速定量法

抄録

Commercially available carbazole contains 2, 3-benzocarbazole as an impurity. For the fluorometric determination of anthracene in the carbazole, it is necessary to remove carbazole and 2, 3-benzocarbazole from the sample prior to the determination. The carbazoles were effectively and rapidly removed by the reaction with formaldehyde in the presence of sulfuric acid and thiourea. Complete recovery of anthracene could be attained by adding thiourea. Two milligrams of the sample was dissolved in 20 ml of cyclohexane. The solution was shaken for 5 min with a mixture of 10 ml of 74 % sulfuric acid containing 200 mg of thiourea and 0.1 ml of formalin. Anthracene could be determined by measuring the relative fluorescence intensity of the cyclohexane layer at 400 nm with excitation at 375 nm. As a standard, 0.1 g/ml solution of anthracene was used. The determination limit of anthracene in carbazole was 0.005 %. The carbazoles could be removed in about 6 min.