DALIBORCA CRISTINA VLAD, VICTOR DUMITRASCU, ROXANA POPESCU, ADINELA CIMPORESCU, CRISTIAN S. VLAD, BOGDAN CORNELIU ANDOR COMPARISON OF PLASTIC AND GLASS COLLECTION AND PIPETTING OF WHOLE BLOOD FOR COCAINE ASSAY BY GC-MS Trace level detection of drugs is routinely monitored in toxicology laboratory. Whole blood testing is an essential component in evaluation the nature and the concentration value of the ingested drug prior to initiate the therapy. One of the most important steps in lab working protocol regards collection and pipetting technique for whole blood assay. The aim of the study was to compare the effects of whole blood collection and pipetting technique for cocaine and its major metabolite (benzoylecgonine) in trace level assay. The results evidenced that by using both glass and plastic tips, concentration values were lower when using polymeric tube for collection and plastic tips for pipetting compared to glass tubes and plastic tips. In the case of glass containers, the higher concentrations were obtained when using glass pipette. The lower values can be caused by blood adherence to the inner circumferential surface of the pipette tip.