Ion‐spray mass spectrometry of marine neurotoxins

TLDR

The study examined ion‑spray mass spectrometry for detecting domoic acid, saxitoxin, and tetrodotoxin. Liquid chromatography coupled with ion‑spray mass spectrometry was used to identify domoic acid and certain isomers in shellfish extracts. All three toxins produced strong protonated positive‑ion spectra with minimal fragmentation, domoic acid also yielded a prominent negative‑ion [M–H]⁻, tandem MS generated informative fragments, and flow‑injection limits were 30 pg for saxitoxin, 100 pg for domoic acid, and 200 pg for tetrodotoxin.

Abstract

Abstract Ion‐spray mass spectrometry was investigated for the analysis of three marine neurotoxins: domoic acid, saxitoxin and tetrodotoxin. All three compounds gave positive‐ion spectra with abundant ions of protonated molecules and no significant fragmentation. Domoic acid gave a negative‐ion spectrum with a strong [M–H] − ion. Tandem mass spectrometry provided useful fragment‐ion spectra for all compounds. Detection limits for flow injection analyses with selected‐ion monitoring were determined to be 30 pg for saxitoxin, 100 pg for domoic acid and 200 pg for tetrodotoxin. Combining liquid chromatography with ion‐spray mass spectrometry allowed the determination of domoic acid and some of its isomers in toxic shellfish tissue extracts.