Direct detection of boldenone sulfate and glucuronide conjugates in horse urine by ion trap liquid chromatography–mass spectrometry

Detection, quantification and confirmation of anabolic steroids in equine plasma by liquid chromatography and tandem mass spectrometry

“…With the advance of LC-MS technology, the emphasis has shifted in favor of this new technology. There are reports of LC-MS methods for quantitative determination of anabolic steroids such as testosterone, nandrolone, and trenbolone in human or bovine plasma or serum [16][17][18][19], in bovine or equine or human urine [20][21][22][23][24][25][26][27][28] and in human saliva [29][30][31]. To our knowledge, there is no report on LC-MS methods for qualitative and quantitative determination of anabolic steroids in equine plasma.…”

Direct detection of serum psilocin glucuronide by LC/MS and LC/MS/MS: time-courses of total and free (unconjugated) psilocin concentrations in serum specimens of a “magic mushroom” user

“…Liquid chromatography/mass spectrometry (LC/MS) and LC/MS/MS are powerful tools for directly detecting highly polar and nonvolatile conjugates; many research groups including our own have reported the detection of conjugates of various compounds using LC/MS and LC/ MS/MS [8][9][10][11][12][13][14][15][16][17][18][19][20]. We reported the identification of urinary psilocin glucuronide (PCG) by LC/MS and LC/MS/MS, and the optimization of its enzymatic hydrolysis conditions for urine, and showed that all PC excreted into urine was in the form of its glucuronide conjugate [15]; in the present study, this line of experiments has been extended to PCG and PC in human serum.…”

Quantification of Glucuronide Metabolites in Biological Matrices by LC-MS/MS

“…If endogenous glucuronides are present in "blank" samples , like for instance steroid glucuronides, then it is necessary to spike the blanks with labeled glucuronides for matrix effect and recovery calculation (Pozo, Van Eenoo et al 2008). The glucuronides can be retained to various extents on a reversed phase (Trontelj, Bogataj et al 2007), on a strong anion-exchange (Pu, McKinney et al 2004), on a mixed-mode (Kakimoto, Toriba et al 2008) and even on strong and weak cation exchange sorbents (Okura, Komiyama et al 2007), depending on the ionization and lipophilic properties of the aglycone. Even highly polar glucuronides and sulfates, like paracetamol conjugates can have a high recovery on mixed-mode weak anion exchange sorbents like Waters Oasis WAX (Sunkara and Wells 2010).…”