Kelly B N, et al. Drug Testing and Analysis, 2013, 5(11-12), 890-895.
Glycerol is an endogenous compound, one of the World Anti-Doping Agency banned threshold substances as a plasma volume expander. Glycerol in the blood is derived mostly from the metabolism of triglycerides for energy, and if the kidney limit (1.3 mg/mL) is exceeded, the glycerol goes to the urine. This work employed glycerol-d5 as an internal marker and measure athletes' urinary glycerol by gas chromatography-mass spectrometry (GC-MS) as a test for anti-doping.
Preparation of samples containing glycerol-d5
· A stock solution of glycerol was dissolved in methanol at 1 mg/ml, and used it as calibration curve points in synthetic urine, at 1, 3, 5, 7, 10, 15, 20, 25, 30 and 60 g/ml. The stock solution of the internal standard, glycerol d5, was prepared at a concentration of 5 mg/ml in methanol, and a working solution was generated by diluting it 100 times to achieve a concentration of 50 μg/ml. A control sample was prepared at 5 g/ml and 20 g/ml levels in synthetic urine.
· 20 μl of urine was transferred into a silanized glass tube (13x100 mm) for GC-MS analysis, added 1.3 g of internal standard, and evaporated it in a turbo-vap for 20 minutes at 40°C. After evaporation, 100 μl of N-methyl-N-trimethylsilyltrifluoroacetamide (MSFTA) was added to the residue and it was left to sit at 75°C for 20 minutes. The samples were transferred into vials for GC-MS analysis after they had incubated.
Zhang S L, et al. Microscopy and Microanalysis, 2005, 11(S02), 790-791.