Salt Effect in High-voltage Assisted Laser Desorption Ionization Mass Spectrometry / 分析化学

ABSTRACT

Salteffectinhigh-voltageassistedlaserdesorptionionizationmassspectrometry(HALDI-MS)has been studied under both positive and negative ion modes using L-tyrosine, β-cyclodextrin, α-lipoic acid, as well as the complex formed between α-lipoic acid and β-cyclodextrin as the test analytes. Compared the mass spectra obtained with and without the addition of salt, it is found that HALDI-MS can tolerate a higher amount of salt than electro spray ionization mass spectrometry ( ESI-MS) . Also, the addition of salt can enhance the HALDI-MS signal intensity of the complex ion of α-lipoic acid and β-cyclodextrin, and we suggest that such signal-enhancement effect is due to the formation of the three component complex consisting of α-lipoic acid,β-cyclodextrin and the positive ion of the salt.