LC-MS Applications for Environmental Analysis

Fast and Accurate Determination of

Algal Toxins in Water Using Online

Preconcentration and UHPLC-Orbitrap

Mass Spectrometry

Jaewon Choi,

Je-Heon Jang,

Jennifer Massi,

Jonathan Beck

Water Analysis & Research Center, K water, Daejeon 306-711, Korea

Thermo Fisher Scientific, San Jose, CA, USA

Application Note 606

Key Words

EQuan, Exactive, Orbitrap, algal toxins, cyanobacteria, water analysis,

online concentration

Goal

To develop a column-switching technique based on online preconcentration

and high-resolution, full-scan

Thermo Scientific ™ Orbitrap ™ m

ass

spectrometry to obtain fast and accurate results for the determination of

algal toxins in drinking water.

Introduction

When the density of the colonies of

Microcystis

and

Nodularia

cyanobacteria surpass a certain level, they

produce hepatotoxic substances called microcystins and

nodularins, respectively,

while

Anabaena

and

Apha-

zinomenon

are known to produce a neurotoxin called

anatoxin.

These toxins can cause deaths of wild animals

and domestic livestock. Human poisoning can lead to

gastrointestinal and allergy-like reactions and, in rare

occasions, death. Of the cyanobacteria species,

Microcystis

has been observed to be dominant in the majority of

eutrophication events. Microcystins, the toxins it

produces, are cyclic peptides comprised of seven amino

acids, each with a relatively large molecular mass ranging

from 900 to 1,100 Da. There are approximately 60 to 85

variants of microcystins reported to date (Figure 1).

4,5

Moreover, nodularins produced by

Nodulariais

are

peptide-based hepatotoxins similar to microcystins.

According to the World Health Organization (WHO),

microcystins are chemically stable and can have an

adverse impact on human health if present in a water

supply source.

Prior research has shown that the

microcystins -YR, -RR, and -LR (Figure 1) are the most

common isomers detected, and that microcystin-LR is the

most toxic. Based on these results, the WHO has set forth

a water quality guideline specifying that the microcystin-LR

concentration be maintained below 1 ng/mL. This

guideline is currently being used in Korea as part of a

candidate list for drinking water standards.

Figure 1. Structures of the cyclic peptide microcystins and

nodularin