Effect of addition of antibiotics and an antioxidant on the stability of tissue reference materials for domoic acid, the amnesic shellfish poison

Abstract

Five separate reference materials (RMs) were prepared from a mussel (Mytilus edulis) tissue containing domoic acid (DA) from scallop hepatopancreas (Pecten maximus). Homogenates were separately spiked with antibiotics, an antioxidant, or a combination of both. Control materials did not contain any additives and were prepared from lightly cooked and autoclaved mussel tissues. Stability studies were run over a 148-day period at three different temperature conditions: -20 degrees C, +4 degrees C and +40 degrees C. DA contents in all materials were characterised by HPLC-UV. Homogeneities were demonstrated at the beginning of the study, with coefficients of variance of less than 4% (n = 9). DA was stable at -20 degrees C in all materials. The control materials showed significant degradation after two days at +40 degrees C, and after eight days at +4 degrees C. Each of the materials containing additives demonstrated better stability during the initial period of the study. In addition there was no significant degradation in any of the materials with additives stored at +4 degrees C over the duration of the study. The material containing a combination of the antibiotics and the antioxidant displayed the best stability of all the materials. There was no significant reduction in DA concentration at all temperature conditions after eight days, and after 32 days the decrease at +40 degrees C was still <20 %. Following this, a DA laboratory reference material (LRM) was prepared and, based on previous results, spiked with both the antioxidant and antibiotics. A short-term stability study on this material gave similar results to the corresponding material in the additives study. This study shows that combined use of the additives investigated in the preparation of a mussel tissue reference material for DA ensures analyte stability for a period of up to eight days at temperatures of up to +40 degrees C, a condition that is particularly important when shipping test materials globally. Aliquots of individual feasibility materials used in the study.

A mussel tissue certified reference material for multiple phycotoxins. Part 4: certification

“…With the increased use of LC-MS for multi-toxin monitoring, the need for a CRM certified for multiple groups of toxins has also increased. An international collaboration to produce a freeze-dried mussel tissue (Mytilus edulis) CRM (CRM-FDMT1) [11] was initiated following a series of feasibility studies [7,[11][12][13][14][15]. This Electronic supplementary material The online version of this article (doi:10.1007/s00216-016-0004-0) contains supplementary material, which is available to authorized users.…”

A mussel (Mytilus edulis) tissue certified reference material for the marine biotoxins azaspiracids

“…During this moisture adjustment step, a number of stabilizing agents were added at a concentration of 0.02 % (w/ w) in the final material. Previous studies have shown that a combination of antioxidant and antibiotics is beneficial for the stability of some shellfish toxins, and importantly, they are beneficial for the stability of the mussel matrix [38].…”

Feasibility of gamma irradiation as a stabilisation technique in the preparation of tissue reference materials for a range of shellfish toxins

“…Previous studies have shown that the oxidative rancidity of lamb meat increased with increasing dose of radiation [11] but use of small quantities of antioxidants have been shown to inhibit this lipid peroxidation [12]. Parallel studies have shown that use of antioxidants alone can improve the stability of DA in mussel tissue RMs [13] and they have been used in the preparation of the matrix CRMs available for shellfish toxins [1].…”