Study of the matrix effects of tetrodotoxin and its content in cooked seafood by liquid chromatography with triple quadrupole mass spectrometry

Abstract

Tetrodotoxin is a marine biotoxin with high acute toxicity. The levels in cooked seafood will help us to assess its intake in humans and may help assess the risk of toxicity. However, heavy matrices hinder the direct quantitation of tetrodotoxin. A quantitative method of measuring tetrodotoxin in cooked seafood using liquid chromatography with triple quadrupole mass spectrometry was established in this study. Tetrodotoxin was extracted from the sample matrix using 2% formic acid in methanol and cleaned using a cation exchange cartridge. The cleanup conditions were optimized. The matrix effects were determined using the postextraction spiking method and by comparing the slope of the linear regression equation in sample matrix to that in solvent. The limit of detection in the sample matrix was 5 μg/kg and the limit of quantification was 10 μg/kg. The mean recoveries at three spiking levels were 66.9-89.2% with relative standard deviations of 5.0-10.8% (n = 6) in five different matrices. Tetrodotoxin was found at concentrations of 26.1-2462 μg/kg in nine of 83 cooked seafoods tested in this study. Eight analogs of Tetrodotoxin were detected in the samples studied.

Analytical Method Optimization of Tetrodotoxin and Its Contamination in Gastropods

“…The extraction of TTX from seafood mainly included two methods: boiling-assisted extraction with HCl or HAc/water [ 15 , 16 , 17 , 22 ] and ultrasound-assisted extraction with an HAc/methanol/water mixture [ 19 , 20 , 23 , 25 ]. The boiling-assisted extraction method has a good effect on protein precipitation, but there is a loss in the recovery of TTX.…”

“…Multiple reaction monitoring (MRM) mode was applied for TTX and IS. TTX and its analogues were measured according to the transitions of [M+H] + > [M+H-H2O] + (23 eV) and [M+H] + >162 (37 eV) [ 23 ]. The analogues included in this study were 11-oxoTTX ([M+H] + 336), 4-epiTTX ([M+H] + 320), 5-deoxyTTX or 11-deoxyTTX ([M+H] + 304), 4,9-anhydroTTX ([M+H] + 302), 11-norTTX-6(S)-ol or 11-norTTX-6(R)-ol ([M+H] + 290), 5,6,11-trideoxyTTX ([M+H] + 272), and 4,9-anhydro-5,6,11-trideoxyTTX ([M+H] + 254) [ 18 ].…”

Analysis of monofluoroacetic acid in urine by liquid chromatography-triple quadrupole mass spectrometry and preparation of the positive sample by the bioconversion from monofluoroacetamide to monofluoroacetic acid in vitro

“…Ion pair reagent in the mobile phase would present negative effects to MS measurements. Hydrophilic columns were reported to be good at separation of polar compounds without ion pair reagents [16][17][18][19][20][21]. Amide column, which behaves hydrophilic function for chromatographic separation, was introduced to separate FAcOH in urine in this study.…”

Fast Determination of Sodium Monofluoroacetate in Liquid Milk and Dairy Powder by Hydrophilic Interaction Liquid Chromatography-Triple Quadrupole Mass Spectrometry

“…However, this kind of reagents in the mobile phase would present negative effects to MS measurements. For its hydrophilic function, an amide column was reported to be good at separation of polar compounds under acid condition without ion pair reagents (Diez et al 2015;Kalikova et al 2013;Kotoni et al 2014;Xu et al 2015). An amide column was introduced to separate monofluoroacetate in this study.…”