Development and validation of a direct injection liquid chromatography-tandem mass spectrometry method for the analysis of illicit drugs and psychopharmaceuticals in wastewater

•A large volume direct injection LC-MS/MS method was developed and validated.•Rapid quantification of 19 illicit drugs and psychopharmaceuticals in wastewater.•Sensitivity similar to methods using solid-phase extraction for pre-concentration.•Codeine and tramadol were present in the highest concentrations in raw wastewater.