差分非色散红外法测量不同盐度海水样品的总溶解无机碳研究

Research on the Detection of Dissolved Inorganic Carbon in Seawater with Different Salinities through Non-Dispersive Infrared Detector

海洋碳循环是全球碳循环的重要组成部分,是影响全球变化的关键控制环节。海洋是地球最大的碳库,是地球吸纳CO2的重要缓冲器。海水中溶解无机碳是海洋CO2系统的重要参数,利用AS-C3型溶解性无机碳分析仪进行不同盐度海水溶解无机碳的测量,利用t检验法检验使用仪器的测量精度,探寻盐度与海水总溶解无机碳的关系。实验结果表明:AS-C3型溶解性无机碳分析仪的测量精度在±0.3μmol/L左右,测量过程中无系统差异;海水盐度与总溶解无机碳呈正相关关系,即盐度增大,海水总溶解无机碳增加。最后总结了海水总溶解无机碳测量时的影响因素,如N2纯度、气流状况、实验过程中的温度控制等。

The ocean carbon cycle is a vital component of the global carbon cycle and a critical control link affecting global climate change. As the largest carbon sink on the Earth, the oceans function as an effective buffer for absorbing CO2. Seawater dissolved inorganic carbon（DIC） is an important parameter of the ocean CO2 system.Aimed at exploring the relationship between salinity and DIC, the AS-C3 DIC analyzer was used for the measurement of DIC in seawater with different salinities, and the t-testing method was adopted to inspect the measurement accuracy of the equipment. The experiment results show that the AS-C3 DIC analyzer has a measurement accuracy of around ± 0.3 mol/L for different samples and no systematic difference is observed in the measuring process. Seawater salinity and DIC is positively correlated, in other words, salinity rises with increasing DIC in seawater. Finally, the factors affecting the measurement of DIC are summarized, including the purity of nitrogen, the stability of air flow and temperature control in the experiment process.