Authors: Joshua Cooper, IsilDilek, UmaSreenivasan 
        Presented at Mass Spectrometry Application to the Clinical Lab (MSACL), San Diego, CA, January 2012 
        
        
            Abstract
        
        
			LC-MS/MS is a powerful tool that brings numerous benefits to the clinical sample analysis arena. However, due to the complexity of the instrumentation there are some unique challenges that also accompany these benefits. Even following sample extraction and cleanup, matrix effects from the samples can cause interferences or impact ionization efficiency. Deuterium-labeled internal standards are the most common and prevalent labeled internal standards used to compensate for matrix effects. Some deuterium labeled compounds may exhibit hydrogen-deuterium scrambling/exchange in the collision cell which can impact MS/MS transition selection.