High performance liquid chromatography and mass spectrometry(HPLC-MS) has grown to become a mature and routinely used technique in analytical chemistry since 1980'. HPLC-MS is an online coupling system of HPLC, a separation technique that can be applied to the extremely complex mixtures, and MS, the most sensitive method of molecular analysis that has the potential to yield information of the molecular weight as well as the structure of the analyte. It provides a low limit of detection and as an identifier ...