BUNSEKI KAGAKU
Print ISSN : 0525-1931
An analytical method of polynuclear hydrocarbons in coal tar
Hidetsuru MATSUSHITAYoshio ESUMIAkira SUZUKITakashi HANDA
Author information
JOURNAL FREE ACCESS

1972 Volume 21 Issue 11 Pages 1471-1478

Details
Abstract
This paper describes a new analytical method for polynuclear hydrocarbons in coal tar. This method consists of the following procedures; i) extraction of polynuclear hydrocarbons in coal tar by liquid-liquid partitions, ii) separation of polynuclear hydrocarbons into each component by two-dimensional dual band thin-layer chromatography, and iii) spectrofluorometrical analysis of each component.
Polynuclear hydrocarbons in coal tar were extracted by a series of liquid-liquid partitions of cyclohexane containing coaltar-dimethyl sulfoxide(DMSO), (DMSO +20 vol% HCl; 1 : 1, v/v)-cyclohexane, cyclohexane-water, cyclohexane-5% NaOH, and cyclohexane-water. The residual water in the final cyclohexane solution was removed by adding small amounts of sodium sulfate. anhydride. The cyclohexane solution was then evaporated to dryness in a reduced pressure and at low temperature (ca. 40°C) with the help of a rotary evaporator. The residue was dissolved in a small volume of benzene. A part of the benzene solution was applied onto the aluminum oxide G layer of the thin-layer chromatoplate which had been composed of two adsorbent layers of aluminum oxide G and 26% acetylated cellulose. The first development was carried out on aluminum oxide G layer with n-hexane-ethyl ether (19 : 1, v/v) in a chamber kept at about 20% in relative humidity. The second development was carried out on the acetylated cellulose layer with methyl alcohol-ethyl ether-water (4 :4 : 1, v/v). The polynuclear hydrocarbons thus separated were detected on the acetylated cellulose layer as small fluorescent spots under ultraviolet rays (365 and 253 mμ). Each spot on the thin-layer was scraped off into a small centrifuge-tube, and polynuclear hydrocarbon in it was extracted with benzene by centrifugation. Polynuclear hydrocarbon in the benzene extract was analysed by spectrofluorometry.
We applied this method to the analysis of the coal tar which had been used as a raw material for the production of fire-brick. The extract by the liquid-liquid partition was separated into 93 fluorescent spots by the thin-layer chromatography. Of these spots, 24 polynuclear hydrocarbons including benzo(e)pyrene and perylene were identified spectrofluorometrically. The identified hydrocarbons included 10 active or suspected carcinogens such as benzo(a)pyrene, dibenzo(a, h)pyrene and dibenzo(a, i)pyrene. The contents of 13 polynuclear hydrocarbons in the coal tar were also determined. The content of benzo(a) pyrene was 7400 ppm, that of dibenzo(a, h)pyrene 120 ppm, and that of dibenzo(a, i)pyrene 270 ppm.
Content from these authors
© The Japan Society for Analytical Chemistry
Previous article Next article
feedback
Top