Oct 01, 2016 · Six different types of sample inserts/vials possessing different volumes, shapes and materials were employed in this study. 150 μL conical glass insert (31 × 5 mm, tip 15 mm), 200 μL conical glass insert (31 × 5 mm, tip 9 mm), 250 μL conical glass-silanized insert (31 × 6 mm, tip 15), 250 μL conical glass-silanized insert with plastic spring (29 × 5.7 mm) and 300 μL