457 Mass balance equation Zheng Yu, 2005 ( 7)) (mL) =VH,i+VH,i-1 (10.7) VH,i VH,i-1 i (i-1 mL) L L L ( 8) (mL/Lsubstrate) = VH,i VH,i x 1000 mL (10.8) (mL) (Normalization) Standard temperature and pressure, STP)