Tubing color Internal diameter Volume/cm, µl Volume of 66 cm, µl S/N red 0.005’=125 µm 0.123 8.1 180 purple 0.006’=150 µm 0.182 12 145 yellow 0.007’=175 µm 0.248 16 135

Table 1: Impact of postcolumn volume on S/N.