2.3.3. Processing of raw extracts
Prior to HPLCeMS/MS, all extracts in organic solvents were diluted using an equal volume of ultrapure water and centrifuged at10 C and 9000 r/min for 10 min. Prior to GC injection, the raw
solvent extracts obtained by the LLE required treatment by MgSO4 in order to reduce the residual amount of water. The acetonitrile extracts were shaken with 150 mg MgSO4 per each ml, while the 2-propanol extracts were first diluted using an equal volume of n-hexane and then shaken with 150 mg MgSO4 per each ml of resulting solution. MgSO4 was subsequently removed by centrifu-gation at 3000 r/min for 3 min. Pure solvent extracts were injected directly into GC.