The operating conditions were excitation 290 nm and แอลฟา emission 330 nm. A normal phase column
(100 Si, 250 mm × 4.6 mm i.d., 0.5 ไมโครm particle size, Microsorb, Varian Inc., Walnut Creek, CA, USA) was used with n-hexane/isopropanol (99.5/0.5, v/v) as a mobile phase.