Measurement of benzoylecgonine in whole blood using the Abbott ADx analyzer

An alternate procedure has been developed for the processing of whole blood for the estimation of benzoylecgonine with the use of the Abbott ADx reagents and analyzer. This procedure allows for handling of relatively large numbers of samples without the need to evaporate extraction solvent. Blood samples were diluted with an equal volume of phosphate buffer-methanol (80:20 v/v), and the proteins were removed by centrifugation through a membrane filter device. A comparison of the proposed method with an acetone solvent extraction procedure has been made, and results were shown to be equivalent. Recoveries of 94-105% benzoylecgonine were obtained for added concentrations of 25-500 ng/mL.