The invention discloses an online
trapping and analyzing method for benzo[a]
pyrene in thermal
cracking products, and an apparatus thereof, and belongs to the technical field of analytic detection. The method comprises the following steps: filling a sample into a thermal
cracking chamber, carrying out aerobic thermal
cracking under a programmed heating condition, directly introducing the thermal cracking products to the cold
injection port of a gas chromatograph through a transmission pipeline, and
trapping through refrigerating by
liquid nitrogen; and carrying out programmed heating on the cold
injection port after finishing the thermal cracking, allowing the thermal cracking products to be gasified and to enter a gas chromatograph-
mass spectrometer, and quantitatively analyzing the benzo[a]
pyrene in the thermal cracking products through adopting a selected
ion mode. The apparatus comprises
helium (1), a
nitrogen-
oxygen gas mixture (2), a triple valve (3), a flow controller (4), a flow controller (5), a
handle (6), a thermal cracker (7), the transmission pipeline (8), a nut (9), an injection isolation pad (10), the cold
injection port (11) and the gas chromatograph-
mass spectrometer (12). According to the invention, the method has the advantages of good reappearance, high
recovery rate, simple operation, and experiment
error reduction; and the apparatus has a simple structure.