Comparison of sample preparation strategies for the extraction of methylmalonic acid prior to LC-MS/MS analysis

The screening for elevated levels of methylmalonic acid (MMA) in serum is commonly used as a clinical diagnostic indicator of cobalamin (vitamin B12) deficiency in humans. MMA is commonly analyzed using LC-MS/MS with or without prior derivatization.

This poster summarizes various sample preparation strategies for the extraction of MMA from serum without the necessity for derivatization, prior to LC-MS/MS analysis. A range of techniques of varying complexity were evaluated: protein precipitation, phospholipid depletion, supported liquid extraction and solid phase extraction using both silica and polymer-based mixed-mode anion exchange chemistries. Method performance was evaluated for evaporative effects, assay recovery, ion suppression and phospholipid removal.