Dear all
I'm trying to remove soluble N compounds from tree rings using Soxhlet 
apparatus for 4h in 1:1 (v:v)mixture of toluene and ethanol, then in 100% 
ethanol for 4h, and subsequently in distilled water for 1h, according to the 
protocol described by Sheppard and Thompson (2000) but I'm having several 
problems because it is difficult to reconstruct the different phase. In 
particular I don't know how to increase the "yield" and how to capture the 
extract. Do you have some suggestions or references?
I will appreciate a lot any help
best regards
Giovanna Battipaglia, PhD
Environmental Science Department
via Vivaldi 43
81100 Caserta Italy
tel:+39 0823 274648
fax: +39 0823 274605