A single-step method for determination of the specific radioactivity of lipids

The use of a liquid scintillation counter to measure both the mass and the radioactivity content of charred 14C-labeled lipid bands from thin layer chromatoplates has been evaluated. Following lipid mass determination from a measurement of the external standard channels ratio, a suitable choice of counting parameters enabled a reproducible and efficient 14C count to be obtained over virtually the whole range of lipid concentrations tested. Although the charring procedure resulted in some loss of radioactivity, the efficiency of counting remained high enough for accurate dpm measurements.