title: Diarrhetic shellfish toxins: improvement of sample clean-up for HPLC determination.
abstract: Okadaic acid and dinophysistoxin-1, the principal toxic components in diarrhetic shellfish poisoning, may be detected by high-performance liquid chromatography and fluorometric measurement as 9-anthrylmethyl esters. However, "greasy" samples may occur and the fluorescent reagent 9-anthryldiazomethane may decompose during storage, resulting in impurities that may seriously interfere with quantitative determination. Ultrasonic treatment of the samples during derivatization with 9-anthryldiazomethane was found to improve reproducibility. This may result from increased access to reactive sites on toxins by 9-anthryldiazomethane due to disruption of micelles formed by toxins and other partly hydrophobic compounds. A procedure for cleaning the derivatized samples, using a 0.1 g silica cartridge column and different eluent compositions from that reported by LEE et al. (1987), was found to facilitate chromatogram interpretation. Deoxycholic acid, a commercial available bile acid, was found to be an acceptable internal standard. The 9-anthrylmethyl esters of okadaic acid, dinophysistoxin-1 and deoxycholic acid, were stable at 4 degrees C for at least seven days when stored dry or in methanol.
authors.affiliation: Department of Food Hygiene, Norwegian College of Veterinary Medicine, Oslo.
authors.forename: O B
authors.initials: OB
authors.lastname: Stabell
authors.forename: V
authors.initials: V
authors.lastname: Hormazabal
authors.forename: I
authors.initials: I
authors.lastname: Steffenak
authors.forename: K
authors.initials: K
authors.lastname: Pedersen
mesh_terms: D000818:Animals; D000873:Anthracenes; D049872:Bivalvia; D002851:Chromatography, High Pressure Liquid; D004952:Esters; D004988:Ethers, Cyclic / Q000302:isolation & purification*; D005456:Fluorescent Dyes; D008387:Marine Toxins / Q000302:isolation & purification*; D019319:Okadaic Acid / Q000031:analogs & derivatives; D011714:Pyrans / Q000302:isolation & purification*; D015203:Reproducibility of Results; D014465:Ultrasonics
chemical_list: D000873:Anthracenes; D004952:Esters; D004988:Ethers, Cyclic; D005456:Fluorescent Dyes; D008387:Marine Toxins; D011714:Pyrans; C027347:9-diazomethylanthracene; D019319:Okadaic Acid; C051904:dinophysistoxin 1