Thesis (M.Sc.)--Chulalongkorn University, 2003

Six adsorbents were evaluated for sampling and quantitative analysis of VOCs which released from HDD parts using adsorption/thermal desorption-GC-MS technique. The adsorbents employed were Tenax TA, Tenax GR, Carbotrap B and C, Carbopack B and C. Porous polymer adsorbents revealed higher adsorption efficiency for a wide range from low to high molecular weight compounds whereas graphitized carbon black was more suitable for high molecular weight compounds. To improve the adsorption efficiency, dual-sorbent was examined. Carbopack and Carbotrap C/B provided better adsorption efficiency than single-sorbent; Tenax TA, especially in the range of C[subscript 10] to C[subscript 15]. The optimum thermal desorption conditions found for purge and trap were 15 minutes at, -60 ํC; trapping temperature and desorption, at 358 ํC for 20 seconds and the secondary adsorption materials, for low molecular weight and high molecular weight compounds were Tenax TA and glass wool, respectively. Moreover, the investigation for the optimum sampling temperature and time for pivot cartridge and spindle motor were explored.