title: Sensitive quantification of IGF-1 and its synthetic analogs in dried blood spots.
abstract: BACKGROUND
  Dried blood spot sample collection could improve detection of the misuse of IGF-1, its analogs and growth hormone. An LC-MS/MS method was developed to measure two IGF-1 peptides and one analog peptide after trypsin digestion. In addition to standard method validation parameters, the effect of hematocrit on cysteine alkylation, trypsin digestion and the selection of internal standard were evaluated.
  
  
  RESULTS
  Quantification of IGF-1 peptides was possible with an LLOQ of 25 ng/ml and imprecision of less than 15%.
  
  
  CONCLUSIONS
  While the effects of hematocrit must be evaluated empirically for each method, dried blood spots are a suitable matrix for the measurement of IGF-1 and its analogs by MS.
authors.affiliation: Sports Medicine Research & Testing Laboratory, 560 Arapeen Drive, Suite 150A, Salt Lake City, UT 84108, USA.
authors.forename: Holly D
authors.initials: HD
authors.lastname: Cox
authors.forename: Cole M
authors.initials: CM
authors.lastname: Hughes
authors.forename: Daniel
authors.initials: D
authors.lastname: Eichner
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D059788:Dried Blood Spot Testing / Q000379:methods*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*
chemical_list: D007334:Insulin-Like Growth Factor I