8-Plex stable isotope labeling absolute quantitation strategy combined with dual-targeted recognizing function material for simultaneous separation and determination of glucosylsphingosine and galactosylsphingosine in human plasma.

Glucosylsphingosine (GlcS) in plasma is considered to be a reliable biomarker of Gaucher disease. The detection difficulty of GlcS is that it is difficult to achieve simultaneous separation and quantification with its isomer galactosylsphingosine (GalS), a biomarker of Krabbe disease. In this work, a multiplexed stable isotope labeling absolute quantization strategy coupled with magnetic dispersive solid phase extraction using new prepared dummy magnetic molecularly imprinted polymers (DMMIPs) has been developed for this purpose by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). 8-Plex Amine-reactive Mass Difference Tags (M360/361/362/363/373/375/376/378-AMDTs), were designed, synthesized and used to label GalS and GlcS in different 8 plasma samples, respectively. Synchronously, M359-AMDTs was prepared and used to label mixed standards of GalS and GlcS, which served as internal standards in UHPLC-MS/MS quantitation. Then DMMIPs possessing dual recognition function were applied for specific enrichment and purification of all GlcS and GalS derivatives from a combined solution of labeled 8-plex plasma samples and mixed standards before UHPLC-MS/MS injection. The labeling efficiency, chromatographic retention and mass spectrometry responses of all the 9 AMDTs reagents were consistent for GlcS and GalS. The established and validated method enabled 8-plex plasma samples quantification in a single UHPLC-MS/MS run (<2.0 min). Good linearity of AMDTs-GlcS/GalS derivatives was obtained in the range of 0.02-800 nM. LODs of GlcS and GalS were both 0.005 nM. The recoveries were in the range of 96.1-107.2%. The method was successfully applied for multiplex quantitative analysis of GlcS and GalS in human plasma samples. The results indicated that this method was capable of better realizing the simultaneous separation and quantification of GalS and GlcS compared to reported methods.