Analysis azaspiracid

European regulations set the limit for azaspiracid toxins content in shellfish that is to be destined to human consumption in 160 pg of azaspiracid eqnwalents/kg in the whole body or any part edible separately (EU 2002). This limit has a higher valne than the NOEL to allow for detection by mouse bioassay, the most commonly nsed method due to the lack of standards for chemical analysis. 

The liver is also typically affected after acute azaspiracid intoxication, showing accmnulation of fat droplets in a microscopic analysis at 1 horn after p.o. administration Fatly liver was observed macro-scopically after 4 hours, inducing the typical change in liver color (Ito et al. 2000). After severe lesions to the liver, recovery lasted for 20 d s (Ito et al. 2002). 

Hess, E, Nguyen, L., Aasen, I, Keogh, M., Kilcoyne, J, McCarron, P., and Aune, T. 2005. Tissue distribution, elFects of cooking and parameters affecting the extraction of azaspiracids from mussels, Mytilus edulis, prior to analysis by liquid chromatography coupled to mass spectrometry. Toxicon 46, 62—71. 

Azaspiracid (AZA-1) and related compounds were involved in a nnmber of recent hnman intoxifications, cansing DSP-like symptoms. The toxic syndrome is called azaspiracid poisoning (AZP). The LC-MS analysis of AZA-1 was reported by Draisci et al. [125]. Isocratic elntion with 85% acetonitrile in 0.03% aqneons TFA from a 1.0-imn-ID Cig colnnm at 30 pl/min was performed. [M+H] was observed at m/z 842. In MS-MS, three snbsequent water losses were observed, next to several other minor fragments. The irrstrumental detection limit was 20 pg, which is cortsiderably better than the conventional mottse bioassay (2.8 pg). Lehane et al. [126] reported the analysis of AZA-1 and fom related compounds in shellfish down to 0.05 pg/ml. The same group compared various SPE methods [127]. They developed a CRM procedtrre with an ion-trap irrstrument for the determination of... 

In a series of papers, the group of Volmer [130-132] studied the analysis of azaspiracid biotoxins. Ultrafast and/or high-resolution LC of azaspiracids on monohthic LC columns was evaluated [130]. Chromatograms of five azaspiracids on a 100-mm and a 700-mm monolithic column are shown in Figure 14.11. Fragmentation of azaspiracids in MS-MS on ion-trap and triple-quadrupole instruments was studied as well [131]. The interpretation was confirmed using accurate-mass data from a Q-TOF instrument. Validation of a quantitative method for AZA-1 was also reported [132]. The LOQ was 5 and 50 pg/ml extract using a triple-quadrapole in SRM mode and an ion-trap instrument, respectively. 

Very recently, Stobo et al. proposed a multiple LC-MS method that allows the detection of YTX together with most of the DSP toxins. The method was set up on a triple quadrupole spectrometer. Chromatographic separation of multiple lipophilic toxins was achieved by using a base deactivated silica C8 column eluted with a 5 mM ammonium acetate-acetonitrile mobile phase under gradient conditions. The method was applied to the analysis of sheUflsh and was validated for the quantitative detection of OA, YTX, PTX-2, and Azaspiracid-1 (AZA-1). 

K. Nicolaou, D. Chen, Y. Li, N. Uesaka, G. Petrovic, T. Koftis, F. Bernal, M. Frederick, M. Govindasamy, T. Ling, P. Pihko, W. Tang, and S. VyskocU, Total s)mthesis and structural elucidation of azaspiracid-1. Synthesis-based analysis of originally proposed structures and indication of their non-identity to the natural product. Journal of American Chemical Society 128 (2006) 2258-2267. 

---