Sensitive profiling of trace neurotoxin domoic acid by pressurized capillary electrochromatography with laser-induced fluorescence detection

Abstract

A stable, sensitive and low-reagent consumption method for the quantification of trace neurotoxin domoic acid (DA) was presented by pressurized capillary electrochromatography (pCEC) with laser-induced fluorescence (LIF) detection.

Advances in the Determination of Nonprotein Amino Acids in Foods and Biological Samples by Capillary Electrophoresis

“…The determination of NPAAs in food provides relevant information about food quality and safety. Different works have demonstrated the importance of analyzing NPAAs in food to detect adulterations [21], to evaluate nutritional quality of foods [24,26] or to detect toxic effects [15,19], among others. When the NPAAs of interest are chiral, their enantiomeric determination can also be a powerful tool to obtain valuable information on the effects of food processing or storage or on the presence of adulterations [42].…”

“…As it can be seen in Table 1, this is the only work in which CEC was applied to the analysis of NPAAs in the period of time reviewed in this article. A solid-liquid extraction followed by a clean-up procedure and a derivatization step with NBD-F was achieved before CEC analysis that was carried out in positive and negative voltage using 5 mM phosphate buffer containing 60 % acetonitrile (pH 2.5), enabling a LOD for domoic acid as low as 10 ng/mL [15]. The developed methodology was compared with a HPLC-MS/MS method showing similar LODs and RSD results, and better recoveries in the case of CEC.…”

“…Fluorescence detection has also been widely employed for the analysis of NPAAs due to its high sensitivity; however, a derivatization procedure is also needed due to the lack of fluorescence of most amino acids. Many derivatization reagents such as 2,3-naphthalenedicarboxaldehyde (NDA) [9,10,11,12,13,14], 4fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) [15,16,17,18], fluorescein isothiocyanate (FITC) [19], 9-fluorenylmethyl chloroformate (FMOC-Cl) [20], benzoyl chloride, 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC), dansyl chloride (DNS-Cl) [21] and o-phthaldialdehyde (OPA) [16] have been employed. An interesting alternative to these detection approaches is mass spectrometry (MS) that presents higher sensitivity and selectivity than other systems [5] and provides structural information being not necessary a derivatization step although sometimes it is also employed.…”