南海北部低浓度磷酸盐的测定与分布  

THE DISTRIBUTION OF LOW-LEVEL PHOSPHATE IN THE NORTHERN SOUTH CHINA SEA

作　　者：袁梁英[1] 戴民汉[1] 

机构地区：[1]近海海洋环境科学国家重点实验室厦门大学环境科学研究中心

出　　处：《海洋与湖沼》2008年第3期202-208,共7页Oceanologia Et Limnologia Sinica

基　　金：国家自然科学基金重点项目,90211020号

摘　　要：应用改进的镁共沉淀法,首次在国内较为系统的测定了南海北部冬、夏两季表层海水中的磷酸盐,冬季其浓度在6.6—95.0nmol/L范围内,平均值为34.5nmol/L,由于受珠江径流影响,表层磷酸盐的水平分布呈现随离岸距离的增加而逐渐减小的趋势;夏季其浓度在6.3—66.6nmol/L范围内,平均值为17.4nmol/L,整体分布较均匀。冬季远岸表层磷酸盐浓度高于夏季,这与南海北部生产力水平的季节变化相一致。南海北部上层磷酸盐存在明显的跃层,冬季跃层的浓度梯度比夏季小;跃层深度与常规方法检测的结果有所不同。The distribution of phosphate in nanomolar level in the northern South China Sea was determined with magnesium-induced coprecipitation （MAGIC） method in an optimized procedure in which precisions reached 1.53% and 6.63% in recovery rate of 95.5%-98.0% for high and low level measurements, respectively. Samples collected in February and July 2004 representing winter and summer were examined. The horizontal distribution of phosphate was found sig- nificantly influenced by the Pearl River discharge, as the concentration decreased with the distance offshore. The results show that in winter, phosphate concentration in the surface water ranged 6.6-95.0 nmol/L in average of 34.6 nmol/L, while it varied 6.3-66.6 nmol/L in average of 17.4 in summer, lower than that of winter. Vertically, the phosphate profile was apparently stratified and the phosphate gradient was smaller in winter than in summer, and thus a nutricline is revealed by this low-level phosphate measurement.

关 键 词：磷酸盐 低浓度 镁共沉淀法(MAGIC) 南海北部 

分 类 号：P734.2[天文地球—海洋化学]