Quantitative determination by liquid chromatography (LC) coupled with mass spectrometry (MS) was achieved for the following 10 toxins found in association with
diarrhetic shellfish poisoning:
okadaic acid (OA),
dinophysistoxin-1 (
DTX1), 7-O-palmitoylokadaic
acid (palOA), 7-O-palmitoyldinophysistoxin-1 (pa1DTX1),
pectenotoxin-1 (
PTX1), pectenotoxin-2 (PTX2), pectenotoxin-2 seco
acid (PTX2SA), pectenotoxin-6 (
PTX6),
yessotoxin (YTX), and
45-hydroxyyessotoxin (YTXOH). Toxins in 2 g of the adductor muscle or the digestive glands of scallops, Patinopecten yessoensis, were extracted with 18 ml of
methanol-water (9:1, v/v), freed of polar contaminants by partition between
chloroform and water, and treated by solid-phase extraction on a
silica cartridge column. Samples containing YTXOH were purified separately on a buffered reversed-phase column. Chromatographic separation was achieved by the following combinations of columns and mobile phases: a Symmetry C18 column with
acetonitrile-0.05%
acetic acid (7:3, v/v) for OA,
DTX1,
PTX6 and PTX2SA; a Develosil ODS column with the same mobile phase for
PTX1 and PTX2; a Capcellpak column with
methanol-2.5%
acetic acid (98:2, v/v) for palOA and palDTX1; and an Inertsil ODS column with methanol-0.2 M
ammonium acetate (8:2, v/v) for YTX and YTXOH.
Carboxylic acid toxins were selectively monitored on [M-H]-
ions, sulfated toxins on [M-Na]-
ions, and neutral toxins on [M+NH4]+
ions. Average recoveries of the toxins spiked to tissue homogenates ranged from 70 to 134%. Detection limits in the muscle ranged from 5 to 40 ng/g and those in the digestive glands from 10 to 80 ng/g.