However, even after this treatment, precipitation of some real extracts was observed to continue during the storage at 4 _C in a HPLC autosampler. For this reason, lowered temperature (_10 _C) was applied during centrifugation of diluted extracts.
In the final method, samples were isolated using unbuffered acetonitrile LLE process (Section 2.3.2).
Obtained extracts were dried prior to GC, whereas prior to HPLC, the extract was mixed
with additional amount of water and centrifuged at _10 _C.