title: Laser ablation electrospray ionization high-resolution mass spectrometry for regulatory screening of domoic acid in shellfish.
abstract: BACKGROUND
  Domoic acid (DA) is a potent neurotoxin that accumulates in shellfish. Routine testing involves homogenization, extraction and chromatographic analysis, with a run time of up to 30 min. Improving throughput using ambient ionization for direct analysis of DA in tissue would result in significant time savings for regulatory testing labs.
  
  
  METHODS
  We assess the suitability of laser ablation electrospray ionization high-resolution mass spectrometry (LAESI-HRMS) for high-throughput screening or quantitation of DA in a variety of shellfish matrices. The method was first optimized for use with HRMS detection. Challenges such as tissue sub-sampling, isobaric interferences and method calibration were considered and practical solutions developed. Samples included 189 real shellfish samples previously analyzed by regulatory labs as well as mussel matrix certified reference materials.
  
  
  RESULTS
  Domoic acid was selectively analyzed directly from shellfish tissue homogenates with a run time of 12 s. The limits of detection were between 0.24 and 1.6 mg DA kg-1tissue, similar to those of LC/UV methods. The precision was between 27 and 44% relative standard deviation (RSD), making the technique more suited to screening than direct quantitation. LAESI-MS showed good agreement with LC/UV and LC/MS and was capable of identifying samples above and below 5 mg DA kg-1wet shellfish tissue, one quarter of the regulatory limit.
  
  
  CONCLUSIONS
  These findings demonstrate the suitability of LAESI-MS for routine, high-throughput screening of DA. This approach could result in significant time savings for regulatory labs carrying out shellfish safety testing on thousands of samples annually. © 2016 Her Majesty the Queen in Right of Canada and John Wiley & Sons Ltd.
authors.affiliation: Measurement Science and Standards, National Research Council Canada, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada. daniel.beach@nrc-cnrc.gc.ca.
authors.forename: Daniel G
authors.identifier: http://orcid.org/0000-0002-5680-2112
authors.initials: DG
authors.lastname: Beach
authors.affiliation: Protea Biosciences Inc., 1311 Pineview Dr., Morgantown, WV, 26505, USA.
authors.forename: Callee M
authors.initials: CM
authors.lastname: Walsh
authors.affiliation: Protea Biosciences Inc., 1311 Pineview Dr., Morgantown, WV, 26505, USA.
authors.forename: Pamela
authors.initials: P
authors.lastname: Cantrell
authors.affiliation: Canadian Food Inspection Agency, 1992 Agency Drive, Dartmouth, NS, B3B 1Y9, Canada.
authors.forename: Wade
authors.initials: W
authors.lastname: Rourke
authors.affiliation: Marine Institute, Rinville, Oranmore, Co. Galway, H91 R673, Ireland.
authors.forename: Sinead
authors.initials: S
authors.lastname: O'Brien
authors.affiliation: Measurement Science and Standards, National Research Council Canada, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada.
authors.forename: Kelley
authors.initials: K
authors.lastname: Reeves
authors.affiliation: Measurement Science and Standards, National Research Council Canada, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada.
authors.forename: Pearse
authors.initials: P
authors.lastname: McCarron
mesh_terms: D000818:Animals; D007608:Kainic Acid / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D007834:Lasers; D008387:Marine Toxins / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012758:Shellfish / Q000032:analysis / Q000592:standards*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D008387:Marine Toxins; C012301:domoic acid; D007608:Kainic Acid