title: Comparison of ELISA and LC-MS analyses for yessotoxins in blue mussels (Mytilus edulis).
abstract: Blue mussels (Mytilus edulis) collected from Flødevigen Bay, Norway, in 2001 and 2002 were analysed for yessotoxins (YTXs) by ELISA and yessotoxin (YTX), 45-hydroxyYTX, and carboxyYTX by LC-MS. Results from the two methods were compared to evaluate the ELISA. The response in the ELISA was 3-13 times higher than LC-MS, probably due to the antibodies binding to other YTX analogues not included in the LC-MS analysis. Nevertheless, the correlation between ELISA and LC-MS was good, with r2 values> or =0.8. The results indicate that the ELISA is a reliable method for estimating the total level of YTXs in mussels, and are consistent with extensive metabolism of algal YTXs in mussels. YTX was a minor component in the blue mussels at all times compared to 45-hydroxyYTX and especially carboxyYTX, except when the P. reticulatum bloom occurred. The results also indicate the presence of significant amounts of YTX analogues in addition to those measured by LC-MS. All samples below 4 mg/kg by ELISA were below the current EU regulatory limit of 1 mg/kg by LC-MS. Therefore, we propose using ELISA as a screening tool with a cut-off limit at 4 mg/kg for negative samples, whereas samples above this limit would be reanalyzed by LC-MS.
authors.affiliation: National Veterinary Institute, P.O. Box 8156 Dep., N-0033 Oslo, Norway. ingunn.samdal@vetinst.no
authors.forename: Ingunn A
authors.initials: IA
authors.lastname: Samdal
authors.forename: John A B
authors.initials: JA
authors.lastname: Aasen
authors.forename: Lyn R
authors.initials: LR
authors.lastname: Briggs
authors.forename: Einar
authors.initials: E
authors.lastname: Dahl
authors.forename: Christopher O
authors.initials: CO
authors.lastname: Miles
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000737:chemistry* / Q000502:physiology; D002853:Chromatography, Liquid / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004988:Ethers, Cyclic / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D008978:Mollusk Venoms / Q000032:analysis*; D009664:Norway; D035964:Oxocins / Q000032:analysis*; D012621:Seasons
chemical_list: C419348:45-hydroxyyessotoxin; D004988:Ethers, Cyclic; D008978:Mollusk Venoms; D035964:Oxocins; C503829:carboxyyessotoxin; C066632:yessotoxin