Aug 26, 2010 · The final solution was syringe-filtered into a vial for analysis. A 50-μL sample was injected onto the system. A 150 × 4.6 mm Hypersil GOLD ODS column (5 μm particle size; Thermo Fisher, Runcorn, UK) was used for separation by HPLC (Aijiren series; Seoul, Korea) prior to spraying into the ion source of LC-MS/MS.