My research work deals with the suitability of dimethyl carbonate as a mobile phase for HPLC-MS. Dimethyl carbonate is a non-toxic, environmentally friendly solvent that could serve as an alternative to conventional solvents like acetonitrile. This project will be performed through the purity testing of caffeine using the Ph. Eur. method with dimethyl carbonate in comparison to the original mobile phase. Then the method will be optimized for HPLC-MS and the matrix effects will be determined via caffeine-extract from green tea.