Nucleic acid is of interest in mass spectrometry, because it has been promising medicine to cure some diseases by working at upper stream of action mechanism with less side effect. Moreover, a molecular confirmation of nucleic acid using mass spectrometer is one of a routine analysis, where cost effectiveness of the instrument is significant factor. Generally negative ion detection is applied to the nucleic acid analysis. However, experimental conditions for positive ion detection have not been examined much, although recently a new bench-top instrument specialized to a linear mode with positive ion detection was introduced to achieve high cost-effectiveness.
Here, the conditions for the positive ion detection will be reported using the benchtop mass spectrometer.