Ahn Soyoun, Magaña Armando Alcazar, Bozarth Connie, Shepardson Jonathan, Morré Jeffery, Dreher Theo, Maier Claudia S
Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA.
Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, USA.
J Mex Chem Soc. 2018;62(2). doi: 10.29356/jmcs.v62i2.386.
The occurrence of harmful algal blooms in nutrient-rich freshwater bodies has increased world-wide, including in the Pacific Northwest. Some cyanobacterial genera have the potential to produce secondary metabolites that are highly toxic to humans, livestock and wildlife. Reliable methods for the detection of cyanobacterial toxins with high specificity and low limits of detection are in high demand. Here we test a relatively new hybrid high resolution accurate mass quadrupole time-of-flight mass spectrometry platform (TripleTOF) for the analysis of cyanobacterial toxins in freshwater samples. We developed a new method that allows the quantitative analysis of four commonly observed microcystin congeners (LR, LA, YR, and RR) and anatoxin-a in a 6-min LC run without solid-phase enrichment. Limits of detection for the microcystin congeners (LR, LA, YR, and RR) and anatoxin-a were <5 ng/L (200-fold lower than the guideline value of 1 μg/L as maximum allowable concentration of MC-LR in drinking water). The method was applied for screening freshwaters in the Pacific Northwest during the bloom and post-bloom periods. The use of high resolution mass spectrometry and concomitant high sensitivity detection of specific fragment ions with high mass accuracy provides an integrated approach for the simultaneous identification and quantification of cyanobacterial toxins. The method is sensitive enough for detecting the toxins in single colonies.
在营养丰富的淡水水体中，有害藻华的发生在全球范围内都有所增加，包括太平洋西北地区。一些蓝藻属有可能产生对人类、牲畜和野生动物具有高毒性的次生代谢产物。因此，对具有高特异性和低检测限的蓝藻毒素检测方法的需求很大。在此，我们测试了一种相对较新的混合高分辨率精确质量四极杆飞行时间质谱平台（TripleTOF），用于分析淡水样本中的蓝藻毒素。我们开发了一种新方法，可在无需固相富集的情况下，在6分钟的液相色谱运行中对四种常见的微囊藻毒素同系物（LR、LA、YR和RR）以及类毒素-a进行定量分析。微囊藻毒素同系物（LR、LA、YR和RR）和类毒素-a的检测限均<5 ng/L（比饮用水中微囊藻毒素-LR的最大允许浓度指导值1 μg/L低200倍）。该方法应用于太平洋西北地区藻华期和藻华后期的淡水筛查。高分辨率质谱的使用以及对具有高质量精度的特定碎片离子的高灵敏度检测，为蓝藻毒素的同时鉴定和定量提供了一种综合方法。该方法灵敏度足以检测单个菌落中的毒素。
