“…Furthermore, extraction solvents should be compatible with the subsequent analytical procedures (Villas-Boas et al, 2005b). A wide range of different extraction solutions have been reported including alcohols, water, acids, bases and organic solvents at high or low temperature (de Koning and van Dam, 1992;Dietmair et al, 2010;Grob et al, 2003;Maharjan and Ferenci, 2003;Ritter et al, 2008;Sellick et al, 2009;Shryock et al, 1986;Villas-Boas et al, 2005a;Villas-Boas et al, 2005b;, and each solution is only suitable for specific classes of metabolites and certain cell types (Canelas et al, 2009;de Koning and van Dam, 1992;Grob et al, 2003;Maharjan and Ferenci, 2003;Rabinowitz and Kimball, 2007;Shryock et al, 1986;Tomiya et al, 2001;Villas-Boas et al, 2005b). Therefore, the extraction protocol is selected depending on the aim of study and the target biological sample (Alvarez-Sanchez, 2010), as well as being based on the nature and level of metabolites extracted (Dunn and Ellis, 2005).…”