Methods and systems are disclosed for detecting mass transfer in a rotating device or rotating system, such as a washing machine or dishwasher. The invention further relates to a lithographic apparatus and a method for determining a total integrated concentration of a substance having a molecular weight falling into a pre-determined range of molecular weights in a gas sample. Moreover, the graft copolymer can serve as a compatibilizer for a polymer blend so as to improve the compatibility of the polymer blend with other polymers, and increase the impact resistance and elongation of the polymer blend, while the physical properties of the original polymers in the polymer blend can still be maintained.