This method is for determining the total mercury concentration in liquefied petroleum gases, using a Nippon Instrument Corporation (NIC) WA-5F mercury analyzer with a NIC LP-WA vaporizer and dry gas meter (DCDa-1C) with a lower limit of quantification of 0.1 mass ppb. Mercury is trapped in a gold trap, released using heat, and quantified using atomic fluorescence spectroscopy (AFS).