In onshore oil and gas industries polymers are considered as a potential pipe material. One special aspect in this field of application is the resistance of the material against the permeation of low-molecular-weight hydrocarbons. These small molecules may permeate through the material and cause environmental problems. In this contribution, the main influencing parameters on the permeation process of low-molecular-weight hydrocarbons through hig-density polyethylene (HDPE a) re investigated by gravimetric analysis. To bypass the limitations of this well-established method a new measuring method based on gas chromatography-mass spectroscopy (GC-MS) techniques is developed. The main advantages of the newly developed system are demonstrated by test measurements of filled polyethylene (PE) pipes. The comparison of the calculated permeation rates of the tested hydrocarbons using both measuring methods showed a good accordance of the results.