Sample 3: ™New ThermoScientific™ National clear-glass, 9 mm vials (C4000-1W) and new closures with PTFE/silicone septa (C5000-54B) were provided as baseline reference samples. Authors Loy Shick, Thermo Fisher Scientific, Rockwood, TN, USA Brian King, Thermo Fisher Scientific, Runcorn, Cheshire, UK Keywords Autosampler, Closures,