An infusion set and an intravenous bag adapter constructed of ultraviolet transmissive thermoplastic are used in spectroscopic validation of pharmaceuticals. The described hardware allows for qualitative and quantitative assurance of medications and is used to prevent medication errors. The thermoplastic is transmissive in the range below 315 nanometers. In one embodiment, the invention comprises a spectrometer and a test chamber that are unaffected by the presence of ambient light. The spectrometer includes an unshielded slot or receptacle into which the test chamber is easily fitted. This embodiment can function well in drug diversion programs for which unused post-op narcotics can be tested.