沉积色素已经成为反映浮游植物生物量和群落结构的有效指标,被广泛应用到研究过去湖泊和海洋生态系统初级生产力变化及其对气候变化与人类活动的响应中.但是由于色素的特殊化学属性,不同的提取和分析方法对不同介质中的色素具有明显的...沉积色素已经成为反映浮游植物生物量和群落结构的有效指标,被广泛应用到研究过去湖泊和海洋生态系统初级生产力变化及其对气候变化与人类活动的响应中.但是由于色素的特殊化学属性,不同的提取和分析方法对不同介质中的色素具有明显的选择性.因此,在不同区域,为获得浮游植物生物量和群落结构等信息,需要选择合适的色素提取和分析方法.本文利用L9（3^4）正交实验方案,对青藏高原中部典型半对流型湖泊（达则错）和双季对流型湖泊（江错）表层沉积物进行对比研究,选择适用于青藏高原湖泊沉积色素的提取和分析方法.对比发现提取试剂的类型及含量、色谱柱和流动相分别是影响湖泊沉积色素提取与分析过程中的关键因素.利用丙酮：甲醇：水混合试剂（80：15：5,体积比）,冰浴超声30s并低温静置6h对于青藏高原湖泊沉积色素提取具有最佳提取效率.在进行色素分析时,反相高效液相色谱（RP-HPLC）系统中采用Eclipse Plus C8色谱柱（150mm×4.6mm,粒径为3.5mm）,流动相A为甲醇：乙腈：0.25m吡啶（50：25：25,体积比）;流动相B为甲醇：乙腈：丙酮（20：60：20,体积比）,流动相A的pH利用醋酸调节为6,柱温保持40℃时,色素分离效果最好.本研究为进一步利用青藏高原湖泊沉积色素研究湖泊初级生产力变化和湖泊生态系统对气候变化和人类活动的响应提供了实验基础.展开更多
Sedimentary pigments are useful proxy indicators of phytoplankton biomass, community structure, primary productivity and human influence in lacustrine and oceanic ecosystems. Pigments are relatively labile due to thei...Sedimentary pigments are useful proxy indicators of phytoplankton biomass, community structure, primary productivity and human influence in lacustrine and oceanic ecosystems. Pigments are relatively labile due to their complex chemical structures, which makes the extraction and analysis of sedimentary pigments challenging. In addition, it is important to select appropriate methods to study sedimentary pigments in regions which lack previous investigations. In this study, we adopted the L9（34） orthogonal design to develop methods of extraction and HPLC （high performance liquid chromatography） analysis of sedimentary pigments at two lakes on the Tibetan Plateau： meromictic lake-Dagze Co and dimictic lake-Jiang Co. The orthogonal design comprises 9 combinations of various parameters for extraction and HPLC analysis. The results show that the type and volume of solvent are the most important factors for pigment extraction, and the mobile phase and column selection are the most important for HPLC analysis. For the study sites, we found that the best methods to extract sedimentary pigments are as follows： the use of a mixture of acetone：methanol：water （80： 15：5, v：v：v） as the extraction solvent; sol- vent/sample ratio of 10 mL/g; sonication for 30 s and standing extraction for 6 h. The best methods for HPLC analysis are as follows： Zorbax Eclipse plus C8 column with mobile phase A, methanol：acetonitrile：0.25 M aqueous pyridine （50： 25：25, v ： v ： v） and mobile phase B, methanol： acetonitrile： acetone （20： 60： 20, v： v： v）; pH of mobile phase A adjusted to 6 with acetic acid; and HPLC column temperature maintained at 40~C. The study provides an experimental basis for future investigations of past changes in primary productivity and the response of lake ecosystems to climate change and human activities on the Tibetan Plateau.展开更多
文摘沉积色素已经成为反映浮游植物生物量和群落结构的有效指标,被广泛应用到研究过去湖泊和海洋生态系统初级生产力变化及其对气候变化与人类活动的响应中.但是由于色素的特殊化学属性,不同的提取和分析方法对不同介质中的色素具有明显的选择性.因此,在不同区域,为获得浮游植物生物量和群落结构等信息,需要选择合适的色素提取和分析方法.本文利用L9（3^4）正交实验方案,对青藏高原中部典型半对流型湖泊（达则错）和双季对流型湖泊（江错）表层沉积物进行对比研究,选择适用于青藏高原湖泊沉积色素的提取和分析方法.对比发现提取试剂的类型及含量、色谱柱和流动相分别是影响湖泊沉积色素提取与分析过程中的关键因素.利用丙酮：甲醇：水混合试剂（80：15：5,体积比）,冰浴超声30s并低温静置6h对于青藏高原湖泊沉积色素提取具有最佳提取效率.在进行色素分析时,反相高效液相色谱（RP-HPLC）系统中采用Eclipse Plus C8色谱柱（150mm×4.6mm,粒径为3.5mm）,流动相A为甲醇：乙腈：0.25m吡啶（50：25：25,体积比）;流动相B为甲醇：乙腈：丙酮（20：60：20,体积比）,流动相A的pH利用醋酸调节为6,柱温保持40℃时,色素分离效果最好.本研究为进一步利用青藏高原湖泊沉积色素研究湖泊初级生产力变化和湖泊生态系统对气候变化和人类活动的响应提供了实验基础.
基金supported by National Key Basic Research Programs of China (Grant No. 2012CB956100)the National Natural Science Foundation of China (Grant Nos. 41072120 & 41321061)
文摘Sedimentary pigments are useful proxy indicators of phytoplankton biomass, community structure, primary productivity and human influence in lacustrine and oceanic ecosystems. Pigments are relatively labile due to their complex chemical structures, which makes the extraction and analysis of sedimentary pigments challenging. In addition, it is important to select appropriate methods to study sedimentary pigments in regions which lack previous investigations. In this study, we adopted the L9（34） orthogonal design to develop methods of extraction and HPLC （high performance liquid chromatography） analysis of sedimentary pigments at two lakes on the Tibetan Plateau： meromictic lake-Dagze Co and dimictic lake-Jiang Co. The orthogonal design comprises 9 combinations of various parameters for extraction and HPLC analysis. The results show that the type and volume of solvent are the most important factors for pigment extraction, and the mobile phase and column selection are the most important for HPLC analysis. For the study sites, we found that the best methods to extract sedimentary pigments are as follows： the use of a mixture of acetone：methanol：water （80： 15：5, v：v：v） as the extraction solvent; sol- vent/sample ratio of 10 mL/g; sonication for 30 s and standing extraction for 6 h. The best methods for HPLC analysis are as follows： Zorbax Eclipse plus C8 column with mobile phase A, methanol：acetonitrile：0.25 M aqueous pyridine （50： 25：25, v ： v ： v） and mobile phase B, methanol： acetonitrile： acetone （20： 60： 20, v： v： v）; pH of mobile phase A adjusted to 6 with acetic acid; and HPLC column temperature maintained at 40~C. The study provides an experimental basis for future investigations of past changes in primary productivity and the response of lake ecosystems to climate change and human activities on the Tibetan Plateau.
