title: Quantitative determination of gymnodimine-A by high performance liquid chromatography in contaminated clams from Tunisia coastline.
abstract: Quantitative determination by high performance liquid chromatography (HPLC) was performed for gymnodimine-A (GYM-A), a phycotoxin responsible for the contamination of Tunisian clams. This study demonstrates a rapid and reproducible HPLC-ultraviolet (UV) method for extraction, detection and quantification of GYM-A in toxic clams. The extraction of GYM-A from the digestive gland of clams in acetone, subsequent clean-up with diethyl ether and extraction with dichloromethane is the more valid protocol. Chromatography analyses were performed using a gradient of acetonitrile-water (10:90 to 90:10), containing trifluoroacetic acid (0.1%) for 20 min at 1 mL/min rate with a C18 column. Recovery rates exceeded 96%, and limits of detection and quantification were 5 ng/mL and 8 ng/g digestive gland, respectively. Repeatability and reproducibility were tested for various samples containing different levels of GYM-A. A significant correlation was observed between toxicity level of samples and the determined amount of GYM-A. Also, the persistence of GYM-A in contaminated clams from Boughrara lagoon was demonstrated. The kinetics discharge study of GYM-A in controlled medium, during 1 month, showed that the process of depuration was biphasic with an exponential discharge of 75% of the total amount of sequestered GYM-A during the first 12 days followed by a slow discharge (>10%) for the subsequent days up to the seventeenth day. This is the first time that a quantitative study of GYM-A in clams from Tunisian coasts is performed through the development of a new method for detection and quantify of this phycotoxin. We found HPLC-UV a reliable and suitable alternative to the mouse bioassay.
authors.affiliation: Laboratoire des Toxines Alimentaires, Institut Pasteur de Tunis, B.P. 74, 1002, Tunis-Belvédère, Tunisia.
authors.forename: Riadh
authors.initials: R
authors.lastname: Marrouchi
authors.forename: Faten
authors.initials: F
authors.lastname: Dziri
authors.forename: Nawel
authors.initials: N
authors.lastname: Belayouni
authors.forename: Asma
authors.initials: A
authors.lastname: Hamza
authors.forename: Evelyne
authors.initials: E
authors.lastname: Benoit
authors.forename: Jordi
authors.initials: J
authors.lastname: Molgó
authors.forename: Riadh
authors.initials: R
authors.lastname: Kharrat
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D006575:Heterocyclic Compounds, 3-Ring / Q000032:analysis*; D006844:Hydrocarbons, Cyclic / Q000032:analysis*; D007097:Imines / Q000032:analysis*; D012623:Seawater; D014416:Tunisia
chemical_list: D006575:Heterocyclic Compounds, 3-Ring; D006844:Hydrocarbons, Cyclic; D007097:Imines; C407350:gymnodimine