Improved method to determine succinylacetone in dried blood spots for diagnosis of tyrosinemia type 1 using UPLC-MS/MS

We describe an improved diagnostic method for tyrosinemia type 1 based on quantifying succinylacetone in dried blood spots by ultra-performance liquid chromatography tandem mass spectrometry. Succinylacetone extracted from a single 3/16 inch disk of specimen collection paper containing a dried blood spot was derivatized with dansylhydrazine, separated on an Acquity UPLC BEH C-18 column (2.1 x 50 mm, 1.7 mu m) and detected by electrospray ionization tandem mass spectrometry. Succinylacetone derivative eluted at 0.6 min with a complete run time of 1 min. Using a C-13(4) labeled succinylacetone as an internal standard, the calibration plot was linear up to 100 mu mol/L with a detection limit (S/N = 3) of 0.2 mu mol/L. Intra-day (n = 13) and inter-day (n = 10) variations were better than 10%. The cutoff level of succinylacetone in dried blood spots from healthy infants obtained by the current method was 0.63 mu mol/L (n = 151). In dried blood spots from patients with established tyrosinemia type 1 (n = 11), concentration of succinylacetone was 6.4-30.8 mu mol/L. Copyright (c) 2008 John Wiley & Sons, Ltd.