A mass of 0.5 mg of plant tissues was placed in a glass mortar with 2 g of the
previously cleaned sea sand and 2.0 mL of n-hexane. The materials were mixed in
the glass mortar using a glass pestle under liquid nitrogen to obtain a homogenous
material suitable for column packing. The blend was then packed into a 5 mL syringe
with three circles of filter paper at the bottom.