Automated on-line solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry for determination of lipophilic marine toxins in shellfish

Jorge Regueiro; Araceli E Rossignoli; Gonzalo Álvarez; Juan Blanco

doi:10.1016/j.foodchem.2011.04.054

Automated on-line solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry for determination of lipophilic marine toxins in shellfish

Food Chem. 2011 Nov 15;129(2):533-540. doi: 10.1016/j.foodchem.2011.04.054. Epub 2011 May 4.

Authors

Jorge Regueiro¹, Araceli E Rossignoli², Gonzalo Álvarez³, Juan Blanco²

Affiliations

¹ Centro de Investigacións Mariñas (Xunta de Galicia), Apartado 13, E-36620 Vilanova de Arousa, Pontevedra, Spain. Electronic address: regueiro.jorge@cimacoron.org.
² Centro de Investigacións Mariñas (Xunta de Galicia), Apartado 13, E-36620 Vilanova de Arousa, Pontevedra, Spain.
³ Centro de Investigacións Mariñas (Xunta de Galicia), Apartado 13, E-36620 Vilanova de Arousa, Pontevedra, Spain; Facultad de Ciencias del Mar, Departamento de Acuicultura, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile.

PMID: 30634263
DOI: 10.1016/j.foodchem.2011.04.054

Abstract

Automated on-line solid-phase extraction (SPE) coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for fast determination of lipophilic marine toxins in shellfish samples. The direct coupling of an on-line SPE column to LC-MS/MS was accomplished using column switching techniques. Suitable chromatographic separation was performed on a reversed-phase C18 column under alkaline conditions (pH 11). The selected reversed-phase C18 SPE column allowed rapid and efficient on-line desalting of hydrolysed shellfish samples, avoiding signal suppression during mass spectrometry detection. Furthermore, the on-line SPE procedure allowed reducing matrix effects observed in raw and hydrolysed shellfish extracts. The proposed method was evaluated in terms of linearity, precision, accuracy and limits of detection (LODs). Quantitative recovery (97-102%) and satisfactory inter-day precision (RSD<8%) were achieved for all target compounds. LODs in the sub-μgkg^-1 level (0.37-0.68μgkg^-1) were obtained for all toxins except for okadaic acid, which showed a value of 2.75μgkg^-1. Several mussel samples from North-western Spain were finally analysed in order to demonstrate the applicability of the method. Okadaic acid was the predominant toxin in all samples, although other lipophilic toxins were also detected.

Keywords: Column switching; Lipophilic marine toxins; Liquid chromatography–tandem mass spectrometry; Mussel; On-line solid-phase extraction; Shellfish poisoning.