We want to analyse the total epicuticular wax content of Brassica leaves (normal cultivar of Brussels Sprout). We want to use the modified analysis of Žnidarčič et al., 2008 (Acta agriculturae Slovenica, 91). In short you get a leaf, wash the surface with n-hexane which you evaporate from a pre-weighted vessel and weigh again.

Our idea is to simplify this by using leaf discs of 2-3 cm diameter and putting them directly to a light-weight dish (pre-weighted), wash with 5-7 ml solvent, remove the disc after 1 min and after drying it, weighing it again.

Since we have a balance (Sartorius MC 5) that has a readability of 1 microgram (though surely you cannot weight this, but need more to have a reasonable reading), and a limited maximum weight range of up to 5 g, we wonder if a leaf disc is enough or if you need a whole leaf to have a reasonable weighing.

I'm also not really sure what this balance can resolve, when we tried leaf discs, the readings were not really stable and sometimes negative results occurred.

The question is now how much grams of Brassica leaf material do you need approximately for sufficient wax, so that you can measure this reliably?

If you need a whole leaf, how can you get the solvent (this will be then surely about 50 -100 mL to cover the leaf), in a small and light-weight dish without losing too much wax?