title: Evaluation of micro-colorimetric lipid determination method with samples prepared using sonication and accelerated solvent extraction methods.
abstract: Two common laboratory extraction techniques were evaluated for routine use with the micro-colorimetric lipid determination method developed by Van Handel (1985) [2] and recently validated for small samples by Inouye and Lotufo (2006) [1]. With the accelerated solvent extraction method using chloroform:methanol solvent and the colorimetric lipid determination method, 28 of 30 samples had significant proportional bias (α=1%, determined using standard additions) and 1 of 30 samples had significant constant bias (α=1%, determined using Youden Blank measurements). With sonic extraction, 0 of 6 samples had significant proportional bias (α=1%) and 1 of 6 samples had significant constant bias (α=1%). These demonstrate that the accelerated solvent extraction method with chloroform:methanol solvent system creates an interference with the colorimetric assay method, and without accounting for the bias in the analysis, inaccurate measurements would be obtained.
authors.affiliation: Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 6201 Congdon Boulevard, Duluth, MN 55804, USA.
authors.forename: Nanditha
authors.initials: N
authors.lastname: Billa
authors.affiliation: Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 6201 Congdon Boulevard, Duluth, MN 55804, USA.
authors.forename: Dylan
authors.initials: D
authors.lastname: Hubin-Barrows
authors.affiliation: Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 6201 Congdon Boulevard, Duluth, MN 55804, USA.
authors.forename: Tylor
authors.initials: T
authors.lastname: Lahren
authors.affiliation: Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 6201 Congdon Boulevard, Duluth, MN 55804, USA. Electronic address: burkhard.lawrence@epa.gov.
authors.forename: Lawrence P
authors.initials: LP
authors.lastname: Burkhard
mesh_terms: D003124:Colorimetry / Q000379:methods*; D008055:Lipids / Q000032:analysis*; D012997:Solvents / Q000737:chemistry*; D013010:Sonication; D013025:Glycine max / Q000737:chemistry
chemical_list: D008055:Lipids; D012997:Solvents
keywords: Accelerated solvent extraction; Lipid measurement; Micro-colorimetric