[Quantitative determination of tetrodotoxin in poisoned biological samples by two-dimensional liquid chromatography-tandem mass spectrometry].

Tetrodotoxin （TTX） is a powerful small-molecule neurotoxin primarily produced by specific marine endosymbiotic bacteria and can be enriched during symbiosis with aquatic organisms such as pufferfish， gastropods， and blue-ringed octopuses. TTX prevents sodium ions from entering nerve cells， which affects neuromuscular conduction and leads to progressive paralysis and even death due to respiratory failure. Poisoning ascribable to the ingestion of TTX-containing seafood has occurred occasionally in some coastal areas of China. The early identification of toxins and the administration of symptomatic detoxification therapies can improve the resuscitation success rates of poisoned patients. The concentration of TTX in clinical biological samples reflects the degree of patient poisoning and their prognosis. A method was established for the determination of the TTX in poisoned biological samples by two-dimensional liquid chromatography-tandem mass spectrometry （2D-LC-MS/MS）. A human plasma or urine sample （100 μL） was accurately pipetted into a 2-mL centrifuge tube， sequentially added a 10 mg/L kasugamycin solution （10 μL； internal standard）， ultrapure water （150 μL）， and 0.5% （v/v） acetic acid in acetonitrile （250 μL） as the extraction solvent， after which the mixture was subjected to vortex mixing at 2 200 r/min for 10 min and centrifugation for 10 min at 15 000 r/min and 4 ℃. The supernatant was roughly separated using a first-dimensional reverse-phase C