Liquid chromatographic post-column oxidation method for analysis of paralytic shellfish toxins in mussels, clams, scallops, and oysters: single-laboratory validation.
A single-laboratory validation study was conducted for the LC post-column oxidation analysis of paralytic shellfish toxins (PST): saxitoxin (STX); neosaxitoxin (NEO); gonyautoxins (GTX) 1-5; decarbamoyl gonyautoxins (dcGTX) 2 and 3; decarbamoyl saxitoxin (dcSTX); and N-sulfocarbamoyl-gonyautoxin-2 and 3 (C1 and C2) in mussels (Mytilus edulis), soft shell clams (Mya arenaria), scallops (Placopectin magellanicus), and oysters (Crassostrea virginicus). The instrumental technique was developed for the analysis of PST in shellfish as an alternative to the precolumn oxidation method, AOAC Official Method 2005.06, and a replacement for the current AOAC biological method 959.08. The method used reversed-phase LC with post-column oxidation and fluorescence detection. Test materials for method recovery were prepared by fortification of blank material with a cocktail of PST. Materials used to determine method repeatability and intermediate precision were prepared by blending blank material with naturally incurred material. The target total toxicity levels evaluated in the study were 0.40, 0.80, and 1.60 mg STX x diHCl equivalents per kilogram [(eq/kg) 1%, 1, and 2 times the regulatory limit]. Linearity, recovery, and within-laboratory precision parameters of the method were evaluated. Correlation coefficients of the calibration curves for all toxins studied were > 0.99. Total toxin recovery ranged from 94 to 106% at the three levels of interest. Repeatability and intermediate precision RSD ranged from 2 to 7% and 2 to 8%, respectively. The method LOD and LOQ (assuming the presence of all toxins) were determined to be equivalent to 0.18 and 0.39 mg STX x diHCl eq/kg. The method is intended for a regulatory framework and will be submitted for an AOAC collaborative study.
Van de Riet
Jeffrey M
JM
Canadian Food Inspection Agency, Dartmouth Laboratory, 1992 Agency Dr, Dartmouth, NS, Canada B3B 1Y9. Jeffrey.vanderiet@inspection.gc.ca
Gibbs
Ryan S
RS
Chou
Faith W
FW
Muggah
Patricia M
PM
Rourke
Wade A
WA
Burns
Garth
G
Thomas
Krista
K
Quilliam
Michael A
MA
D000818:Animals; D049872:Bivalvia; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D008387:Marine Toxins / Q000032:analysis* / Q000633:toxicity; D010125:Ostreidae; D010084:Oxidation-Reduction; D010243:Paralysis / Q000139:chemically induced; D049897:Pectinidae; D012015:Reference Standards; D015203:Reproducibility of Results; D012758:Shellfish / Q000032:analysis*; D012996:Solutions; D013050:Spectrometry, Fluorescence
D008387:Marine Toxins; D012996:Solutions