An evaluation of the measurement of drugs of abuse by commercial and in-house horizontal thin layer chromatography.

We have compared an in-house horizontal thin layer chromatography (TLC) method with a commercial TLC screening kit (Toxi-Lab) to find the most suitable method for screening urine for opioid drugs. The in-house TLC procedure is cheaper and more efficient than the commercial TLC method and is ideal as a confirmatory method when used in conjunction with other established laboratory methods. The in-house TLC method is useful for one-off requests and is able to differentiate between small quantities (0.1-0.5 mg/L) of the different, commonly abused opioids and their metabolites, which means that it is well suited for use at a local Drug Addiction Unit as a routine screening service.