Liquid Chromatography/Mass Spectrometry of Domoic Acid and Lipophilic Shellfish Toxins with Selected Reaction Monitoring and Optional Confirmation by Library Searching of Product Ion Spectra

Abstract

LC/MS methodology for the analysis of domoic acid and lipophilic toxins in shellfish was developed using a hybrid triple quadrupole linear ion trap mass spectrometer. For routine quantitation a scheduled selected reaction monitoring (SRM) method for the analysis of domoic acid, okadaic acid, dinophysistoxins, azaspiracids, pectenotoxins, yessotoxins, gymnodimines, spirolides, and pinnatoxins was developed and validated. The method performed well in terms of LOD, linearity, precision, and trueness. Taking advantage of the high instrument sensitivity, matrix effects were mitigated by reducing the amount of sample introduced to the mass spectrometer. Optionally, samples can be analyzed using information dependent acquisition (IDA) methods, either in positive or negative mode, which can provide an extra level of confirmation by matching the full product ion spectra acquired for a sample with those from a specially constructed spectral library. Methods were applied to the analysis df a new certified reference material and Canadian mussels (Mytilus edulis) implicated in a 2011 diarrhetic shellfish poisoning (DSP) incident. The scheduled SRM method enabled the screening and quantitation of multiple phycotoxins. As DSP had not previously been observed in this area of Canada, positive identification of putative toxins was accomplished using the IDA and spectral search method. Analysis of the 2011 toxic mussel samples revealed the presence of high levels of dinophysistoxin-1, which explained the DSP symptoms, as well as pectenotoxins, yessotoxins, and variety of cyclic imines.

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

“…For extraction, LSE procedures are commonly used for shellfish toxin determination [2,5,20,21], and recent work has shown the utility of MSPD in the analysis of these compounds as well [10]. LC-MS is the only detection and measurement technique offering sufficient sensitivity and precision for most of the target analytes in CRM-FDMT1.…”

“…Liquid chromatography-mass spectrometry (LC-MS) has proven to be a powerful technique for the analysis of multiple phycotoxins in a single run and has been implemented in many shellfish monitoring laboratories worldwide [1][2][3][4][5]. Recently, LC-MS has replaced the rodent bioassay as the official reference method for monitoring lipophilic algal toxins in shellfish [6].…”

High resolution mass spectrometry for quantitative analysis and untargeted screening of algal toxins in mussels and passive samplers

“…To achieve this goal, different studies have developed and validated quantitative methods for the analysis of phycotoxins, typically using low resolution mass spectrometry (LRMS) [4][5][6][7][8][9]. This technique is now being increasingly used for monitoring [10,11] and for characterization of reference materials [12,13]. Additionally, methods using high resolution mass spectrometry (HRMS) have recently been developed and quantitatively validated for some marine toxins [14][15][16].…”

“…Several approaches have been used to alleviate matrix effects in the quantitative analysis of lipophilic marine toxins. These approaches include SPE cleanup and column flushing [23,24], matrix-matched calibration and standard addition [24][25][26], reduction of the injection volume [11], use of an internal standard and use of a different ionization source such as APCI [19].…”

Identification of gymnodimine D and presence of gymnodimine variants in the dinoflagellate Alexandrium ostenfeldii from the Baltic Sea

“…Besides 12-methylgymnodimine isolated from an A. ostenfeldii strain from the U.S. East Coast, gymnodimine A and 12-methylgymnodimine have been found together with spirolides in isolates from a recent bloom of A. ostenfeldii in the Netherlands ( Van de Waal et al, 2015). Moreover, novel fatty acid ester metabolites of gymnodimine A (de la and several unknown gymnodimine-like compounds (McCarron et al, 2014) have been detected in shellfish by liquid chromatographyemass spectrometry (LCeMS). Compared to other cyclic imines, such as the structurally related pinnatoxins (Araoz et al, 2011) and spirolides (Gueret and Brimble, 2010), knowledge on gymnodimines is still limited.…”