mance including increasing the UV scan rate, changing the injec-tor needle seat, re-plumbing the system with red PEEKsil™ Tubing (SGE), and using a semi-micro flow cell. The fully porous Luna® 2.5 µm HST C18 100 x 2.0mm and the Kinetex® Core-Shell Tech-nology 5 µm C18 50 x 4.6mm were from Phenomenex, Torrance, CA.