Unbound MEDLINE

Refinement of AOAC Official Method 2005.06 liquid chromatography-fluorescence detection method to improve performance characteristics for the determination of paralytic shellfish toxins in king and queen scallops.

Abstract

AOAC Official Method 2005.06 LC-fluorescence detection (FLD) method is an official alternative to the mouse bioassay for the determination of paralytic shellfish poisoning (PSP) toxins in bivalve shellfish. To validate the method for species of relevance to the UK official control monitoring program, the method performance characteristics were tested for whole king and queen scallops. Validation showed that, while the performance was generally acceptable for the quantitation of non-N-hydroxylated toxins, poor toxin recovery and sensitivity was evident for the analysis of N-hydroxylated toxins following periodate oxidation. These effects occurred in a range of scallop samples with variable temporal and spatial sources. The effects were also noted in other laboratories following a small interlaboratory study. As a result, the method was refined to improve the recovery and sensitivity of analysis following the periodate oxidation step in the PSP method for scallops. Performance improved through alterations to the preparation of the periodate oxidant, use of higher volumes for C18 cleanup, and injection volumes in combination with the use of a king scallop matrix modifier for oxidation of N-hydroxylated toxin calibration standards. A single-laboratory validation of the refined method showed that the selectivity, linearity, sensitivity, recovery, and precision were acceptable and similar to values reported previously for AOAC Official Method 2005.06 in other bivalve species. Results showed the method to be rugged for all parameters investigated, including small changes to the composition of the new periodate reagent utilized in the refined method. The refined scallops LC method was subsequently compared with the European reference method. PSP-positive scallops showed an excellent agreement between the methods for queen and Atlantic scallops, with a small level of positive bias in the LC results for whole king scallops. These differences were related solely to the use of the highest toxicity equivalence factors for toxin epimeric pairs, with gonyautoxin (GTX)1,4 and GTX2,3 in particular present at high concentrations in the king scallops. Overall, the refined LC-FLD method improved the performance characteristics of AOAC Official Method 2005.06 for the determination of PSP toxins in whole king and queen scallops, and showed a good overall agreement between the official methodologies. It is, therefore, recommended as a more appropriate option for the routine monitoring of PSP toxins in these species.

Links

  • Publisher Full Text
  • Authors

    Turner AD, Hatfield RG

    Institution

    Centre for Environment, Fisheries and Aquaculture Science, Barrack Rd, The Nothe, Weymouth, Dorset DT4 8UB, United Kingdom. andrew.turner@cefas.co.uk

    Source

    Journal of AOAC International 95:1 pg 129-42

    MeSH

    Animals
    Calibration
    Chromatography, High Pressure Liquid
    Chromatography, Ion Exchange
    Hydrogen-Ion Concentration
    Hydroxylation
    Indicators and Reagents
    Limit of Detection
    Marine Toxins
    Oxidants
    Oxidation-Reduction
    Pectinidae
    Periodic Acid
    Peroxides
    Proteins
    Reference Standards
    Reproducibility of Results
    Saxitoxin
    Shellfish Poisoning
    Solid Phase Extraction
    Spectrometry, Fluorescence
    Temperature
    Uncertainty

    Pub Type(s)

    Journal Article
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    22468351