海水黄色物质吸收系数测量中的关键问题探讨

Discussion on the Key Problems in Measuring the Absorption Coefficient of Yellow Substance in Seawater

黄色物质是海洋中的有色可溶性有机物,是重要的水质参数之一。目前实验室黄色物质样品测量技术虽已有标准参考,但测量过程的一些重要变量对测量结果的定量影响仍未明确。基于2016年东印度洋南部水体综合调查所得的实测样品,分析了参比纯水是否过滤和过滤压力等因素对测量结果准确性的具体影响,发现:(1)参比纯水未过滤会使测量结果明显高估,ag(350)和ag(440)的高估程度分别为0.137 m^(-1)和0.114 m^(-1);(2)过滤压力的不同对测量结果影响较为明显,过滤压力越大,测得的吸收系数越大,对于a_g(350),150 mm Hg相对100 mm Hg的平均偏差为0.195 m^(-1),200 mm Hg相对150 mm Hg的平均偏差为0.058 m^(-1);对于ag(440),150 mm Hg相对100mm Hg的平均偏差为0.168 m^(-1),200 mm Hg相对150 mm Hg的平均偏差为0.064 m^(-1)。本文的实验研究可促进实验者对规范中黄色物质样品处理过程以及相关参数设置原因和意义的理解。

The yellow substance in seawater is also called ＂chromophoric dissolved organic matter＂, which is one of the important water quality parameters. At present, there are standard references to the yellow material sample measurement technology, but the quantitative influence of some important variables of the measurement process on the measurement results is still not clear. Based on the measured samples obtained from the survey of water bodies in the southern Indian Ocean in 2016, this paper analyzes the specific effects of the factors such as filtration and filtration pressure on the accuracy of the measurement results. The results show that the reference water without filtration will make the measurement results significantly overestimated. For ag （350） and ag（440）, The deviations are 0.137 m^-1 and 0.114 m-1, respectively. The influence of the filtration pressure on the measurement results is more obvious. Briefly, the greater the filtration pressure, the larger the measured absorption coefficient. For % （350）, the average deviation of 150 mmHg to 100 mmHg is 0.195 m^-1, and that of 200 mmHg to 150 mmHg is 0.058 m^-1 For ag （440）, the average deviation of 150 mmHg to 100 mmHg is 0.168 m^-1, and that of 200 mmHg to 150 mmHg is 0.064 m^-1. The experimental study of this paper can help the researcher to understand the specification of the yellow material sample processing process and the significance of relevant parameters.