For research use only. Not for use in diagnostic procedures.
Isobaric interferences have always been a concern in LC MS/MS assay development and quantitation. SCIEX wanted to understand better what application areas are most affected by this important and difficult issue. We surveyed customers globally across many application areas to identify the assays where new analytical tools like SelexION™ could benefit our customers. The results indicated that lipid analysis struggled the most with isobaric interferences.
SelexION™ technology (differential ion mobility spectrometry; DMS) can be used to greatly reduce isobaric interferences in lipid analyses. DMS uses a discrete, lipid class-specific compensation voltage (CoV) to filter ions into the mass spectrometer and prevents non-targeted precursor isobars from participating in MS/MS events. This results in excellent selectivity, a general reduction in noise, which can improve the overall S/N of the assay.
SelexION™ Technology Removes Isobaric Interference During Quantitation. Pooled human serum lipid extract was analyzed by LC-MS/MS. An MRM transition for the molecular species PE 40:5 yielded an LC chromatogram with significant isobaric interference (W). The target peak is actually a shoulder on an adjacent peak, which prevents accurate quantitation. However when using SelexION™, the interfering peaks are removed from the chromatogram.