液质联用技术在测定浮游植物色素与粒级分类中的应用

本研究为探讨液质联用技术在测定黄海浮游植物特征色素含量与粒级分类中应用的可行性,在黄海47个站位取表、中、底三层水样进行了分析,对比了超高效液相色谱(UHPLC)和超高效液相色谱串联三重四级杆质谱(UHPLC-MS/MS)两种仪器的色素检测结果。研究发现UHPLC-MS/MS的灵敏度更高,但多数情况下两种方法检测结果吻合度较好,均适用于黄海色素样品的测定。叶绿素a(Chl a)浓度和浮游植物粒级结构空间分析结果显示,山东半岛近岸和长江口东北侧海域,Chl a浓度较高,小型浮游植物占优势;黄海冷水团海域,Chl a浓度较低,微型和微微型浮游植物比例明显升高。该航次的Chl a绝对浓度和不同粒径浮游植物的贡献率与历史数据相比存在一定差异,这与调查时间、站位以及粒级分析方法的差异有关,需进一步比较研究。

Application of UHPLC-MS/MS in determination of the phytoplankton pigment and size fraction

In order to explore the feasibility of applying ultra-high performance liquid chromatography tandem triple quadrupole mass spectrometry (UHPLC-MS/MS) on pigment analysis and size fraction monitoring, seawater samples collected from 3 different water layers at 47 sites in the Yellow Sea were analyzed, it in terms of pigment concentrations acquired by ultra-high performance liquid chromatography (UHPLC) and UHPLC-MS/MS respectively and results got from the two ways were compared. No observious differences were observed from the result comparisons between the two methods for most cases although UHPLC-MS/MS were more sensitive, and the two methods were both suitable for pigment detection in the Yellow Sea. Based on the pigment results provided by UHPLC-MS/MS, the spatial distribution of chlorophyll a (Chl a) and size fraction were studied. The concentration of Chl a was much higher in the northeast of Yangtze River mouth and coastal waters of Shandong Peninsula, where micro phytoplankton was the dominant size fraction. The concentration of Chl a was much lower in the central Yellow Sea, and the contribution of nano- and pico- phytoplankton increased significantly in this region. Compared with previous studies, the absolute concentrations of Chl a and contribution of size fractions in our study showed some differences, which may be caused by the differences of investigation time, sites or analytical methods. Thus, more comparison study is still needed to further probe the reason behind these differences.