>Dear Isogeochem subscribers- >I'm interested in extracting lipids from prehistoric (low-fired) ceramics in >order to analyze carbon isotopes. I'm looking for C4 vs. C3 plant residues >in the ceramic matrix. I have found literature on lipid extraction by >Evershed, Heron and others, but have not found other sources. Have any of >you done such work? If so, I would greatly appreciate any references, >especially references outside strictly archaeological literature. Thanks! >Janet Schulenberg > >[log in to unmask] >409 Carpenter >Penn State Univeristy >University Park, PA 16802 The classic one with CHCl3-MeOH is Geneva Bligh, E.G. Dyer, W.J. A rapid method of total lipid extraction and purification GenevaCan. J. Biochem. Physiol. Geneva37 Geneva911-917 (1959) Sediments: Collister et al. Organic Geochemistry 21, 645-659 (1994). Soils: Schnitzer and Neyroud Fuel 54, 17-19 (1975) Lichtfouse et al. Organic Geochemistry 23, 865-868 (1995). My favorite 15 min sonication with distillated CH2Cl2 in a beaker (3 times) then filtration on cellulose acetate filters (those of coffee machines give excellent filtration) then concentration under vacuum. Glassware and filters must be pre-washed with distillated CH2Cl2 (of course). For very small samples, extration and filtration may be achieved at the same time in about 5 min. on a pipette Pasteur loaded with coton wool, sand and a bit of thin silica gel (Henner et al, Analusis 25, 51-52 (1997).