A common feature of ribonucleic acids (RNAs) is that they can undergo a variety 
of chemical modifications. As nearly all of these chemical modifications result 
in an increase in the mass of the canonical nucleoside, mass spectrometry has 
long been a powerful approach for identifying and characterizing modified RNAs. 
Over the past several years, significant advances have been made in method 
development and software for interpreting tandem mass spectra resulting in 
approaches that can yield qualitative and quantitative information on RNA 
modifications, often at the level of sequence specificity. We discuss these 
advances along with instrumentation developments that have increased our ability 
to extract such information from relatively complex biological samples. With the 
increasing interest in how these modifications impact the epitranscriptome, mass 
spectrometry will continue to play an important role in bioanalytical 
investigations revolving around RNA.