P. G. Sim

Reference materials for domoic acid, a marine neurotoxin

SummaryDomoic acid was recognized recently [1, 2] to be a marine neurotoxin associated with shellfish harvested or cultured for use as human food. Evidence about the occurrence of domoic acid and its importance to shellfish industries is reviewed. The preparation and certification of two reference materials for the determination of domoic acid, an instrument calibration solution (DACS-1, released by the Marine Analytical Chemistry Standards Program [MACSP] in May, 1989), and a tissue reference material (MUS-1, homogenized soft tissues of Mytilus edulis, released by the MACSP in August, 1989) are described. We believe these are the first certified standards or reference materials to be available for the determination of shellfish toxins, a problem of increasing importance to aquaculturists and the seafood industry, as well as to agencies concerned with the safety of food. The tissue homogenate preparation techniques we have developed and used may be of general interest for the preparation of other tissue reference materials for the determination of other organic compounds, since the sealed, fluid homogenate samples seem acceptably stable without being continuously frozen or refrigerated.

The Use of Copper Immobilized on Silica for Compound Class Fractionation of Polycyclic Aromatic Compounds in Environmental Samples

Abstract Copper immobilized on silica has been investigated as an adsorbent for the fractionation of polycyclic aromatic compounds (PACs) into different compound classes. an open column chromatographic packing based on copper (II) bound to a silica substrate was used as a means of subdividing the PACs into less complex groups of similar compound types. the process has been applied to the fractionation of PACs extracted from a marine harbour sediment, for which the complex mixture of PACs could be separated into three subgroups, the contents of which were: (1) polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and thiophenes; (2) compounds containing pyrrole-type (sp 3-hybridized) nitrogen (carbazoles), and also quinones and other oxygen containing species; and (3) compounds containing pyridine-type(sp 2-hybridized) nitrogen (acridine and its homologues). the fractions thus obtained have been characterized by gas chromatography-mass spectrometry (GC-MS). Extracted mass spectra, obtained from the cres...