Abstract: A method for testing a non-hydrocarbon refrigerant, such as CFC-12 or HFC-134a, in a closed system for hydrocarbons, HCFC-22 refrigerant and ammonia is provided wherein a sample of the non-hydrocarbon refrigerant is withdrawn from the closed system, the pressure of the sample is measured and a metered portion of the sample is passed through a test apparatus (20) including a testing tube (30), a testing tube holder (40) for supporting the testing tube (30) and outfitted with a vent (48) to the atmosphere, and a pressure gauge (70) for indicating the pressure of the sample withdrawn. A medium (38) for indicating the presence of hydrocarbons in the sample flow passing through the testing tube is deposited on a surface disposed in the testing tube. The presence of undesired HCFC-22 refrigerant in the CFC-12 or HFC-134a is indicated by a higher pressure reading on the pressure gauge (70).