A Rapid LC-HRMS Method for the Determination of Domoic Acid in Urine Using a Self-Assembly Pipette Tip Solid-Phase Extraction.

Yiping Zhang,Zhuan Hong,Dawei Chen

doi:10.3390/toxins8010010

Abstract

In this study, we developed a self-assembly pipette tip solid-phase extraction (PTSPE) method using a high molecular weight polymer material (PAX) as the adsorbent for the determination of domoic acid (DA) in human urine samples by liquid chromatography high-resolution mass spectrometry (LC-HRMS) analysis. The PTSPE cartridge, assembled by packing 9.1 mg of PAX as sorbent into a 200 μL pipette tip, showed high adsorption capacity for DA owing to the strong cationic properties of PAX. Compared with conventional SPE, the PTSPE is simple and fast, and shows some advantages in the aspects of less solvent consumption, low cost, the absence of the evaporation step, and short time requirement. All the parameters influencing the extraction efficiency such as pH, the amount of sorbent, the number of aspirating/dispensing cycles, and the type and volume of eluent in PTSPE were carefully investigated and optimized. Under the optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) values of DA were 0.12 μg/L and 0.37 μg/L respectively. The extraction recoveries of DA from the urine samples spiked at four different concentrations were in a range from 88.4% to 102.5%. The intra- and inter-day precisions varied from 2.1% to 7.6% and from 2.6% to 12.7%, respectively. The accuracy ranged from −1.9% to −7.4%.

Highlights

Domoic acid (DA, Figure 1a), a major amnesic shellfish poisoning (ASP) toxin, is a naturally-occurring hydrophilic neurotoxic amino acid produced by algae (e.g., Chondria armata) and accumulates in shellfish, sardines, and anchovies [1]
We developed a self-assembly pipette tip solid-phase extraction (PTSPE) method using a high molecular weight polymer anion exchange material (PAX) as the adsorbent for the determination of domoic acid (DA) in urine by Toxins 2015, 7, page–page liquid chromatography high-resolution mass spectrometry (LC-HRMS) analysis
Value for DA was 0.12 μg/L, and the limit of quantification (LOQ) value was 0.37 μg/L when 100 μL urine was analyzed which were sufficiently low to meet the requirements of routine monitoring and exposure assessment

Summary

Introduction

Domoic acid (DA, Figure 1a), a major amnesic shellfish poisoning (ASP) toxin, is a naturally-occurring hydrophilic neurotoxic amino acid produced by algae (e.g., Chondria armata) and accumulates in shellfish, sardines, and anchovies [1]. Consumption of DA-contaminated shellfish is responsible for severe neurological symptom disorders, such as headache, disorientation, confusion, and short-term memory loss [2,3]. The neurological effects of DA have been attributed to several mechanisms, but the one of concern is through glutamate receptors. As an excitatory amino acid analogue of glutamate, DA displays a very strong affinity for the glutamate receptors, which results in excitotoxicity initiated by an integrative action on ionotropic glutamate receptors. DA binds predominately to N-methyl-D-aspartate (NMDA) receptors in the central nervous system [4,5,6].

Methods

Results

Conclusion