The studies on the silica species in regional and seasonal change, and on development of measurement in pure water

硅藻的活动和海水的循环使硅藻的浓度和种类随季节变化。在东京湾和相模湾的海水中观察到了二氧化硅物种。二聚体和线状四聚体被硅藻消耗。春季，与环状四聚体相比，二聚体和线状四聚体的浓度变得很低。然而，在2003年春季，也就是夏季寒冷的一年，二聚体和线性四聚体并没有降低。2003年秋季，二聚体和线状四聚体的分布与2002年和2004年秋季基本一致。这说明二聚体和线性四聚体在春季的分布反映了夏季是否炎热。通过FAB-MS对二氧化硅物种的测定，很难在纯净水中检测到这些物种。开发了在纯水中制备高浓度二氧化硅的方法。通过这种方式，人工溶液可以复制成与高浓度二氧化硅的河水一样。对该高浓度二氧化硅溶液进行了FAB-MS和ESI-MS检测，并对观察到的二氧化硅形态进行了比较。通过电喷雾质谱(ESI-MS)对二氧化硅物种进行脱溶处理，从而检测到脱水过程中二氧化硅物种的变化。

The silica concentration and species change according to season by the activity of diatom and circulation of seawater. The silica species were observed in seawater of Tokyo and Sagami Bays. Dimer and linear tetramer were consumed by diatom. In spring, dimer and linear tetramer became very low concentration compared with cyclic tetramer. However, in spring of 2003, which was the year of cold summer, dimer and linear tetramer did not become low. And in fall of 2003, the distribution of dimer and linear tetramer was almost same as those in fall of 2002 and 2004. This indicated that the distribution of dimer and linear tetramer in spring showed the hot summer or not.By this measurement of silica species by FAB-MS, it was difficult to detect these species in pure water. The preparation with high concentration of silica in pure water was developed. From this way, the artificial solution could be reproduced just the same as the river water with high concentration of silica. This high concentration silica solution was examined by FAB-MS and ESI-MS, and observed silica species were compared with each other. The silica species were pass the desolvated process by ESI-MS, therefore, detected silica species changed by dehydration.