Determination of dissolved domoic acid in seawater with reversed-phase extraction disks and rapid resolution liquid chromatography tandem mass spectrometry with head-column trapping.
Domoic acid (DA) is the principal neurotoxin responsible for amnesic shellfish poisoning (ASP) and is produced, among other species, by marine diatoms of the genus Pseudo-nitzschia. In this work, a method for the determination of dissolved DA and its isomers present in seawater has been developed, based on a solid-phase extraction (SPE) disks followed by rapid resolution liquid chromatography coupled with tandem mass spectrometry. SPE provided sample desalting and 20-fold concentration of dissolved DA, while complete resolution between DA and its isomers was achieved in less than 3 min with rapid resolution chromatography thus providing high sample throughput. Additionally, a simple on-column chromatographic procedure allowed head-column trapping of DA providing 15-fold higher sensitivity. The conditions developed in this work have shown appropriate quality parameters in a within-laboratory validation. The detection limit was 0.02 ng mL(-1) for the whole method, while trueness ranged between 92.1% and 110.6% recovery and precision between 8.4% and 19.0% relative standard deviation. Expanded uncertainty measured was 1.92, 0.23 and 0.03 for 10.0, 1.0 and 0.1 ng mL(-1) DA concentrations, respectively, which demonstrated the accuracy of this method for confirmation and quantification of DA present at very low concentration levels in seawater.
de la Iglesia
Pablo
P
Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou, km. 5.5, 43540 Sant Carles de la Ràpita, Tarragona, Spain. pablo.delaiglesia@irta.cat
Giménez
Gemma
G
Diogène
Jorge
J
D007608:Kainic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D008387:Marine Toxins / Q000032:analysis*; D009498:Neurotoxins / Q000032:analysis*; D015203:Reproducibility of Results; D012623:Seawater / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012995:Solubility
D008387:Marine Toxins; D009498:Neurotoxins; C012301:domoic acid; D007608:Kainic Acid