title: High-throughput quantitative analysis of domoic acid directly from mussel tissue using Laser Ablation Electrospray Ionization - tandem mass spectrometry.
abstract: Eliminating sample extraction or liquid chromatography steps from methods for analysis of the neurotoxin Domoic Acid (DA) in shellfish could greatly increase throughput in food safety testing laboratories worldwide. To this end, we have investigated the use of Laser Ablation Electrospray Ionization (LAESI) with tandem mass spectrometry (MS/MS) detection for DA analysis directly from mussel tissue homogenates without sample extraction, cleanup or separation. DA could be selectively detected directly from mussel tissue homogenates using MS/MS in selected reaction monitoring scan mode. The quantitative capabilities of LAESI-MS/MS for DA analysis from mussel tissue were evaluated by analysis of four mussel tissue reference materials using matrix-matched calibration. Linear response was observed from 1 mg/kg to 40 mg/kg and the method limit of detection was 1 mg/kg. Results for DA analysis in tissue within the linear range were in good agreement with two established methods, LC-UV and LC-MS/MS (recoveries from 103 to 125%). Beyond the linear range, extraction and clean-up were required to achieve good quantitation. Most notable is the extremely rapid analysis time of about 10 s per sample by LAESI-MS/MS, which corresponds to a significant increase in sample throughput compared with existing methodology for routine DA analysis.
authors.affiliation: National Research Council Canada, Measurement Science and Standards, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada. Electronic address: daniel.beach@nrc-cnrc.gc.ca.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Beach
authors.affiliation: Protea Biosciences Group, Inc., 955 Hartman Run Road, Morgantown, WV, 26505, USA.
authors.forename: Callee M
authors.initials: CM
authors.lastname: Walsh
authors.affiliation: National Research Council Canada, Measurement Science and Standards, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada.
authors.forename: Pearse
authors.initials: P
authors.lastname: McCarron
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000737:chemistry*; D057166:High-Throughput Screening Assays / Q000379:methods*; D007608:Kainic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D053685:Laser Therapy / Q000379:methods; D008387:Marine Toxins / Q000032:analysis*; D009498:Neurotoxins / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D008387:Marine Toxins; D009498:Neurotoxins; C012301:domoic acid; D007608:Kainic Acid
keywords: Algal toxin; Ambient ionization; Amnesic shellfish poisoning (ASP); Direct analysis; LAESI-MS/MS; Shellfish testing