Comparison of two extraction methods (solid phase extraction -SPE- and dispesive liquid liquid microextraction -DLLME) for the determination of opioids and benzodiazepines in urine samples using LC-MS/MS. Each extraction method was validated in terms of recovery and precision at different concentration levels. The files correspond to: SPE: instrumental (1 file), validation at 5 ng/L (1 file), 20 ng/L (1 file) and 60 ng/L (1 file) DLLME: instrumental (1 file), validation at 5 ng/L (1 file), 20 ng/L (1 file) and 60 ng/L (1 file)

Validation paramters evaluated for each extraction technique: solid phase extraction -SPE- and dispesive liquid liquid microextraction -DLLME

MQL = method quantification limit MDL = method detection limit %R = recovery %ME = matrix effect %RSD: relative standard deviation