A GC-MS Procedure for the Measurement of Dopamine in Mouse Striatal Tissue

Abstract A gas chromatographic-mass spectrometric (GC-MS) method for measuring dopamine levels in brain tissue has been developed. Deuterated dopamine was prepared by exchange of the aromatic hydrogens with deuterium. The method involves adding a known amount of deuterated dopamine to the extraction medium or vessel and extracting the brain sample. The sample is acylated with pentafluoropropionic anhydride, and an aliquot of the derivative in benzene injected into a gas chromatography-mass spectrometry-computer system. The ion fragments, m/e = 428 and 431 respectively, of the protium and deuterium form of dopamine pentafluoro-propionate are detected. From the relative intensities of the two forms the concentration of dopamine in the brain samples is determined. Trace amounts of selenium in biological samples were estimated by atomic absorption utilizing a Varian carbon rod flameless atomizer. Samples were digested with nitric perchloric acids, selenium was separated from the interfering sample matrices by...