Abstract
Gas chromatographic screening procedures have been evaluated which permit the detection of stimulants and sedatives in blood after administration of pharmacological doses. The techniques actually used in sample preparations and gas chromatographic work are presented as well as examples of pharmacokinetic studies and postive dope cases. The use of sensitive and selective detectors like the nigrogen-specific detector or a mass spectrometer is absolutely essential for routine work, as for non-specific detectors the number of "false positives" leads to an intolerable work load for the laboratory.