Determination of basic drugs in post mortem tissues: a microextraction technique utilizing GLC/NPD of effluents

A method is described for the estimation of basic drugs and metabolites in post mortem tissues and fluids. The method is based upon the selective extraction of these substances, differential weak acid cleanup, and the final preparation of a microextract that is compatible with the rubidium source found in most nitrogen-phosphorous detectors (NPD). Application of this extract to gas chromatography/NPD allows for the measurement of common basic drugs at subtherapeutic, therapeutic, and toxic concentrations in a variety of tissue matrices (liver, brain, lung, heart, and kidney) using a minimum of sample (less than one gram). Internal standards are used to allow for the quantitative as well as qualitative aspects of the assay. Examples of tissue extract chromatograms containing commonly encountered basic drugs are presented along with precision data.