Figure 1.

Determination of Domoic acid by electrospray mass spectrometry.(A) The electrospray mass spectrometry spectrum of 12.5 mM Domoic acid shows that the dominate ion in the spectrum is m/z 312.2, the pseudomolecular ion [M+H+] of Domoic acid, demonstrating that undegraded Domoic acid was present in the 12.5 mM stock solution; (B) The electrospray mass spectrometry spectrum of 0.0025 mM Domoic acid, the highest dilution used in the experiments, also shows the presence of undegraded Domoic acid.