(12. The following data apply to the drug Rohypnol (fluni- trazepam), FW 313.39/mol: log P pka 2.1 1.8 Structure CH F t1/2 plasma 3hr t1/2 elimination 16-35 hr Answer the following questions: a. Assuming a typical dose of 1 mg, what would be the expected concentration of unchanged drug in a urine sample of 25 ml? b. If the LOD/LOQ for this drug in a mass spectrometer is 2.5 g/L, how long after the dose will it be possible to detect the unmetabolized drug in urine? Elimination 1% unchanged urine; 10% feces and the rest metabolites in urine Source: Galichet, L. Y., et al., eds. Clarke's Analysis of Drugs and Poisons, Vol. 2. London: Pharmaceutical Press, 2004. c. Propose a sample extraction scheme for flunitrazepam from blood. d. The four major peaks in the mass spectrum of this drug are 312, 285, 266, and 238. Propose fragment losses to explain this distribution of peaks. e. Based on the structure of the drug, what distinctive IR spectral features might be expected?