McCarron Pearse, Emteborg Håkan, Hess Philipp
Marine Institute, Marine Environment and Food Safety Service, Rinville, Oranmore, Galway, Ireland.
Anal Bioanal Chem. 2007 Apr;387(7):2475-86. doi: 10.1007/s00216-006-1104-z. Epub 2007 Jan 26.
Two samples of mussels (Mytilus edulis) were collected from the southwest of Ireland. One sample contained domoic acid, the other sample contained okadaic acid, dinophysistoxin-2 and azaspiracid-1, -2 and -3. Wet and freeze-dried reference materials were prepared from each of the two samples to test for differences in homogeneity, stability and extractability of the analytes in either condition. Wet materials were homogenised, aliquoted and hermetically sealed under argon and subsequently frozen at -80 degrees C. Dry materials were similarly homogenised but frozen in flat cakes prior to freeze-drying. After grinding, sieving and further homogenisation, the resulting powder was aliquoted and hermetically sealed. Domoic acid materials were characterised using HPLC-UV, while LC-MS was used for the determination of lipophilic toxins. The extractabilities of all phycotoxins studied were comparable for wet and freeze-dried materials once a sonication step had been carried out for reconstitution of the freeze-dried materials prior to extraction. Homogeneity was assessed through replicate analysis of the phycotoxins (n = 10), and was found to be similar for wet and freeze-dried materials, for both hydrophilic and lipophilic toxins. Water contents were determined for both wet and freeze-dried materials, and particle size was determined for the freeze-dried materials. Stability was evaluated isochronously over eight months at four temperatures (-20, +4, +20 and +40 degrees C). The freeze-dried material containing domoic acid was stable over the whole duration at all temperatures, while in the wet material domoic acid degraded to some extent at all temperatures except -20 degrees C. In freeze-dried and wet materials containing lipophilic toxins, okadaic acid, dinophysistoxin-2, azaspiracid-1 and azaspiracid-2 were stable over the whole duration at all conditions, while concentrations of azaspiracid-3 changed significantly in both materials at some storage temperatures. Figure Aliquots of freeze-dried and wet mussel tissue reference materials containing the various shellfish toxins examined in the study.
从爱尔兰西南部采集了两份贻贝（紫贻贝）样本。一份样本含有软骨藻酸，另一份样本含有冈田酸、鳍藻毒素 -2 以及azaspiracid -1、-2 和 -3。从这两份样本中分别制备了湿态和冻干的参考物质，以测试在这两种状态下分析物的均匀性、稳定性和可提取性的差异。湿态物质进行匀浆、分装，在氩气下密封，随后在 -80℃冷冻。干态物质同样进行匀浆，但在冷冻干燥前制成扁平饼状冷冻。经过研磨、筛分和进一步匀浆后，将所得粉末分装并密封。软骨藻酸物质使用高效液相色谱 - 紫外检测法进行表征，而液相色谱 - 质谱联用仪用于测定亲脂性毒素。一旦在提取前对冻干物质进行超声处理以复溶，那么所有研究的藻毒素在湿态和冻干物质中的可提取性相当。通过对藻毒素进行重复分析（n = 10）评估均匀性，发现对于亲水性和亲脂性毒素，湿态和冻干物质的均匀性相似。测定了湿态和冻干物质的含水量，并测定了冻干物质的粒径。在四个温度（-20℃、+4℃、+20℃和 +40℃）下同步评估八个月的稳定性。含有软骨藻酸的冻干物质在所有温度下整个时间段内都稳定，而在湿态物质中，除了 -20℃外，软骨藻酸在所有温度下都有一定程度的降解。在含有亲脂性毒素的冻干和湿态物质中，冈田酸、鳍藻毒素 -2、azaspiracid -1 和 azaspiracid -2 在所有条件下整个时间段内都稳定，而在某些储存温度下，两种物质中 azaspiracid -3 的浓度都发生了显著变化。图 研究中检测的含有各种贝类毒素的冻干和湿态贻贝组织参考物质的等分试样。
