oral Blood -Analysis by High Performance Liquid ChromatographyfTandem Mass Spectrometry QTRAP (LC-MS/MS QTRAP) for. Compound Rpt Limit comccund Bgt Liroit 4-<:yano-CUMYL-BINACA 0.10 ng/mL AMB-FUBINACA 1.0 ng/mL 4-Huoro-MDMB-BINACA 0.10 ng/ml CUMYL-THPINACA 0.10 ng/mL 5-fluoro-EDMB-PINACA 0.10