Patent ID: 7470778

Claim:
A method for extraction of proteins, protein fragments and/or peptides from a biological sample, comprising treating said biological sample with an extractant, wherein the extractant employed is an ionic liquid of the formula K + A − , wherein K + is a cation selected from the group consisting of ammonium, phosphonium, uronium, thiouronium, guanidinium or a heterocyclic cation and A − is an anion of formula [N(R f ) 2 ] − , wherein R f is a partially or fully fluorine-substituted alkyl having 1 to 8 C atoms or R f2 X, wherein R f2 is a partially or fully fluorine-substituted alkyl having 1 to 8 C atoms and X is SO 2 or CO, or a fluoroalkylphosphate of formula [PF x (C y F 2y+1−z H 6−x ] − , wherein 1≦x<6, 1≦y≦8 and 0≦z≦2y+1; or a mixture of said formulas.