Figure 2From: Analysis of naltrexone and its metabolite 6-beta-naltrexol in serum with high-performance liquid chromatography A chromatogram of a serum standard containing 50 ng/ml naltrexone (RT = 6.99) and 6-β- naltrexol (RT = 6.20), nalorphine (RT = 5.13) as internal standard. Back to article page