1984 Volume 19 Issue 4 Pages 300-307
A liquid chromatographic method is presented for trace determination of 10 polynuclear aromatic hydrcarbons (PAHs), i. e., fluoranthene, pyrene, chrysene, perylene, benzo (k) fluoranthene, benzo (e) pyrene, benzo (a) pyrene, benzo (ghi) perylene, indeno (1, 2, 3-cd) pyrene, and coronene, in airborne particulates. Airborne particulates were collected on a quartz fiber filter for 24 hr by using conventional high volume air sampler. A part of the filter was cut out and placed in a centrifuge tube. Ethanol-benzene (3: 1, v/v) as an extracting medium was added to the tube. After removing bubbles attached to the filter, PAHs were extracted by ultrasonic agitation at 15-20°C for 15 min. Bubbles, which were still attached to the filter, were removed again and PAHs were completely extracted by ultrasonic agitation for another 10 min. The tube was centrifuged at 3, 000 rpm for 10 min. Supernatant of the extract was transferred to another centrifuge tube, 5 % sodium hydroxide aqueous solution was added and the tube was vigorously shaken for 1 min. After centrifugation at 3, 000 rpm for 10 min, upper layer (benzene layer) was transferred to a test tube, concentrated under a reduced pressure and dried under a nitrogen stream. A residue was dissolved in small amount of acetonitrile and analyzed by high performance liquid chromatography with spectroflurometric detection at the specific excitation and emission wavelengths for each PAH. The column consisted of a guard column (4.6 mm i.d.× 33 mm stainless steel column packed with Nucleosil 7C18) and an analytical column (Analytical-PAH, 2.0 mm i.d.×250 mm). Mobile phase was water-acetonitrile (from 65 to 90 vol% acetonitrile, 2.5%/min gradient). Column temperature was 30°C. Recoveries of PAHs from the extract of airborne particulates were 99.2-107 % with 2.0-5.9 % relative standard deviation. The detection limits of PAHs (S/N=2) were 8200 pg. A good agreement was obtained between the analytical results for 10 airborne particulate samples by the proposed method and those by a conventional method including ultrasonic extraction, one-dimensional dual band thin-layer chromatography and spectrofluorometry.
