In Canada in late 1987 there was an outbreak of an acute illness characterized by gastrointestinal symptoms and unusual neurologic abnormalities among persons who had eaten cultivated mussels. Health departments in Canada solicited reports of this newly recognized illness. A case was defined as the occurrence of gastrointestinal symptoms within 24 hours or of neurologic symptoms within 48 hours of the ingestion of mussels. From the more than 250 reports received, 107 patients met the case definition. The most common symptoms were vomiting (in 76 percent of the patients), abdominal cramps (50 percent), diarrhea (42 percent), headache, often described as incapacitating (43 percent), and loss of short-term memory (25 percent). Nineteen patients were hospitalized, of whom 12 required intensive care because of seizures, coma, profuse respiratory secretions, or unstable blood pressure. Male sex and increasing age were associated independently with the risks of hospitalization and memory loss. Three patients died. Mussels associated with this illness were traced to cultivation beds in three river estuaries on the eastern coast of Prince Edward Island. Domoic acid, which can act as an excitatory neurotransmitter, was identified in mussels left uneaten by the patients and in mussels sampled from these estuaries. The source of the domoic acid appears to have been a form of marine vegetation, Nitzschia pungens, also identified in these waters in late 1987. The contaminated mussels from Prince Edward Island were removed from the market, and no new cases have occurred since December 1987. We conclude that the cause of this outbreak of a novel and severe intoxication was the ingestion of mussels contaminated by domoic acid, a potent excitatory neurotransmitter.

Domoic acid (DomA) is an excitatory amino acid which can accumulate in shellfish and finfish under certain environmental conditions. DomA is a potent neurotoxin. In humans and in non-human primates, oral exposure to a few mg/kg DomA elicits gastrointestinal effects, while slightly higher doses cause neurological symptoms, seizures, memory impairment, and limbic system degeneration. In rodents, which appear to be less sensitive than humans or non-human primates, oral doses cause behavioral abnormalities (e.g. hindlimb scratching), followed by seizures and hippocampal degeneration. Similar effects are also seen in other species (from sea lions to zebrafish), indicating that DomA exerts similar neurotoxic effects across species. The neurotoxicity of DomA is ascribed to its ability to interact and activate the AMPA/KA receptors, a subfamily of receptors for the neuroexcitatory neurotransmitter glutamate. Studies exploring the neurotoxic effects of DomA on the developing nervous system indicate that DomA elicits similar behavioral, biochemical and morphological effects as in adult animals. However, most importantly, developmental neurotoxicity is seen at doses of DomA that are one to two orders of magnitude lower than those exerting neurotoxicity in adults. This difference may be due to toxicokinetic and/or toxicodynamic differences. Estimated safe doses may be exceeded in adults by high consumption of shellfish contaminated with DomA at the current limit of 20 microg/g. Given the potential higher susceptibility of the young to DomA neurotoxicity, additional studies investigating exposure to, and effects of this neurotoxin during brain development are warranted.Copyright © 2010 Elsevier Inc. All rights reserved.

Ion-spray mass spectrometry was investigated for the analysis of three marine neurotoxins: domoic acid, saxitoxin and tetrodotoxin. All three compounds gave positive-ion spectra with abundant ions of protonated molecules and no significant fragmentation. Domoic acid gave a negative-ion spectrum with a strong [M-H]- ion. Tandem mass spectrometry provided useful fragment-ion spectra for all compounds. Detection limits for flow injection analyses with selected-ion monitoring were determined to be 30 pg for saxitoxin, 100 pg for domoic acid and 200 pg for tetrodotoxin. Combining liquid chromatography with ion-spray mass spectrometry allowed the determination of domoic acid and some of its isomers in toxic shellfish tissue extracts.

Amnesic shellfish poisoning is a potentially lethal human toxic syndrome which is caused by domoic acid (DA) that originates in marine phytoplankton belonging to the Pseudonitzschia genus. A new sensitive liquid chromatographic-mass spectrometry (LC-MS) method has been developed for the determination of DA in various marine biological samples. The characteristic fragmentation pathways for DA were established using multiple stage MS on selected daughter ions, which were sequentially trapped and fragmented. Chromatography was performed using a gradient of acetonitrile-water (5:95 to 40:60), containing trifluoroacetic acid (0.05%), over 25 min at 0.2 ml/min with a C18 column (Luna-2, 150 x 2.0 mm, 5 microm). Using electrospray ionisation, multiple tandem MS experiments were performed with an ion-trap mass spectrometer (Finnigan MAT LCQ). The protonated DA molecule was the precursor ion, m/z 312, and the relative collision energies were optimised for multiple MS (MS(n), n = 2-4) studies. LC-MS3 using the ions, m/z 266 and 220, from the loss of two HCOOH molecules, produced the best sensitivity data. Calibration data for various MS modes were: MS (0.05-10 microg DA/ml, r2 = 0.9973); MS2 (0.025-10 microg DA/ml, r2=0.9997); MS3 (0.025-10 microg DA/ml, 0.9994). The detection limits (3:1 signal:noise) were better than 0.02 microg DA/ml for LC-MS, 0.014 microg DA/ml for LC-MS2 and 0.008 microg DA/ml for LC-MS3. This method was applied to determine DA in scallop (Pecten maximus) tissues, which subsequently led to the closure of several shellfish harvesting sites on the west coast of Ireland.

During 1998 and early 1999, shellfish samples from sites in Scotland were found to contain the amnesic shellfish poisoning toxin, domoic acid (DA). Two different techniques, liquid chromatography (LC) with UV diode-array detection and LC with mass spectrometric (MS) detection, were used to detect and confirm DA in shellfish extracts. The LC/UV method was validated for routine monitoring by recovery experiments on spiked mussel and scallop tissues with a certified mussel tissue used as reference material. Crude extracts of selected samples as well as extracts cleaned with strong anion exchange (SAX) were analyzed by both LC/UV and LC/MS. Good correlation (linear regression r2 = 0.996, slope = 0.93) between the 2 methods was found for cleaned extracts. Analyses of crude extracts by LC/UV produced false-positive results in 2 crab samples, whereas LC/MS analyses gave accurate results. It was concluded that LC/UV is a valid approach for routine monitoring of DA in shellfish when cleanup is performed with a SAX cartridge to prevent false positives. A variety of shellfish species were surveyed for DA content, including Pecten maximus (king scallops), Chlamys opercularis (queen scallop), Mytilus edulis (blue mussels), Cancer pugaris (crab), and Ensis ensis (razor fish). The highest concentration of DA was 105 microg/g in Pecten maximus.

This paper describes a new method for sensitive, specific and direct determination of domoic acid (DA), the causative toxin of amnesic shellfish poisoning (ASP) syndrome, in shellfish. It is based on combination of hydrophilic interaction liquid chromatography with mass spectrometry (HILIC/MS). The high percentage of organic modifier in the mobile phase and the omission of ion-pairing reagents, both favoured in HILIC, result in enhanced detection limits with MS detection. The new method was set up either on an ionspray ion trap MS instrument operating in MS and MS/MS scanning acquisition modes, or on a turboionspray triple-quadrupole MS system operating in selected ion monitoring (SIM) and multiple reaction monitoring (MRM) acquisition modes. Positive and negative ion experiments were performed. MRM experiments are recommended for screening contaminated shellfish tissue and for quantitative analyses due to highest sensitivity and selectivity. The minimum detection levels for the toxin in tissue were found to be 63 and 190 ng/g in positive and negative MRM experiments, respectively, which are well below the regulatory limit for DA in tissue (20 microg/g). Application to shellfish samples collected in the Adriatic Sea (Italy) in the period 2000-2004 demonstrated for the first time in Italy the presence of DA as a new toxin that has entered the Adriatic Mytilus galloprovincialis toxin profile.Copyright (c) 2005 John Wiley & Sons, Ltd.

液相色谱-串联质谱（LC-MS/MS）法具有高灵敏度、高选择性、高通量等特点，已经成为生物分析的主流方法，广泛应用于新药发现和开发过程中新化学实体及其代谢物的定量分析。然而，由于生物样品基质成分复杂，共洗脱物质会影响分析物的离子化，使分析物的质谱响应增加或降低，从而影响LC-MS/MS分析方法的准确度和精密度。一般而言，离子抑制较离子增强更为常见。因此，在建立LC-MS/MS法时，需要对离子抑制进行评估和校正，并采用不同的策略消除或减少基质效应的影响。本文综述了生物样品分析中基质效应的来源和评估方法，重点介绍了克服基质效应的策略。引起基质效应的物质包括磷脂、盐类、尿素、代谢物等内源性物质和赋形剂、抗凝剂、固定相释放物质及降解产物等外源性物质。目前基质效应的评价方法主要有提取后加入法和柱后灌注法。克服基质效应的策略主要有使用稳定同位素内标，将极性药物衍生化，沉淀蛋白后稀释上清液，优化样品预处理方法、色谱和质谱条件等。结合本课题组的应用实例，重点阐述了建立LC-MS/MS生物分析方法时，为减少基质效应遇到的困难及解决方法。

本文建立了淡水养殖水体中呋喃丹的全自动固相萃取-超高效液相色谱检测方法。选取HLB固相萃取小柱作为水样的富集和净化小柱，水样以5 mL·min-1的速度上样，用10 mL甲醇洗脱。洗脱液经浓缩、定容后，用超高效液相色谱-荧光检测法分析，色谱柱为ACQUITY UPLC BEH C18柱（100 mm × 2.1 mm，粒径1.7 μm），流动相为乙腈-水（40∶60，V/V），流速为0.200 mL·min-1，激发波长为270 nm，发射波长为310 nm。呋喃丹在20~1 000 μg·L-1范围内线性关系良好，相关系数R2 > 0.999，方法检出限为0.100 μg·L-1，定量限为0.250 μg·L-1，在0.250、2.50、10.0 μg·L-1三种加标浓度水平下，平均加标回收率为90.4% ~ 96.3%，相对标准偏差为2.55% ~ 5.10%。该方法自动化程度高、操作简便、快速准确、稳定性好，适用于淡水养殖水体中呋喃丹的测定。

实验采用高效液相色谱-串联质谱法（HPLC-MS/MS）检测2017—2018年福建中部海域养殖贝类麻痹性贝类毒素（PSTs）。结果表明：2018年采集的贝类样本均未检出麻痹性贝类毒素，2017年采集的贝类样本有17批次检出麻痹性贝类毒素，主要检出成分为脱氨甲酰基石房蛤毒素（dcSTX）、膝沟藻毒素（GTX1、GTX2、GTX3、GTX4、GTX5），脱氨甲酰基膝沟藻毒素（dcGTX2、dcGTX3）也占有一定比例，未发现石房蛤毒素（STX）。2017年福建中部海域链状裸甲藻（Gymnodinium catenatum）暴发事件对该海域养殖贝类的麻痹性贝类毒素有一定影响，其中有毒赤潮对贻贝的影响大于牡蛎，而对缢蛏和蛤类则无影响。

福建是我国赤潮多发省份之一，2000—2017年共发现赤潮219起，其中35起赤潮造成养殖损失或群众健康受损事件。做好有毒赤潮应急处置，对保障人民群众生命安全，维护海洋渔业经济健康发展，服务福建生态省建设至关重要。本文以2017年福建中南部沿海海域链状裸甲藻赤潮事件为例，对赤潮事件过程、主要应急处置措施、存在的问题进行分析与讨论。在此次有毒赤潮事件处置过程中，政府部门采取及时控制贝毒超标水产品养殖区源头、根据赤潮动态调整监视监测工作、主动公开赤潮有关情况、适时终止应急响应等措施，有效地遏制赤潮对社会和水产品质量安全等不利影响的进一步扩大，切实保障群众水产品食用安全及生命财产的安全。针对事件过程中暴露出部门联动、赤潮监测能力等方面的不足，提出完善协同应急响应机制、加强地市级基本应急能力建设、利用新技术开展有毒赤潮生物监测、推广快检技术以加强海水贝类质量安全监测等建议。