A Direct Bicarbonate Detection Method Based on a Near-Concentric Cavity-Enhanced Raman Spectroscopy System

作者：Yang, Dewang; Guo, Jinjia^*; Liu, Chunhao; Liu, Qingsheng; Zheng, Ronger

来源：Sensors (Switzerland), 2017, 17(12): 2784.

DOI：10.3390/s17122784

• laser Raman spectroscopy
• bicarbonate
• direct detection
• ocean application

Raman spectroscopy has great potential as a tool in a variety of hydrothermal science applications. However, its low sensitivity has limited its use in common sea areas. In this paper, we develop a near-concentric cavity-enhanced Raman spectroscopy system to directly detect bicarbonate in seawater for the first time. With the aid of this near-concentric cavity-enhanced Raman spectroscopy system, a significant enhancement in HCO3- detection has been achieved. The obtained limit of detection (LOD) is determined to be 0.37 mmol/L-much lower than the typical concentration of HCO3 in seawater. By introducing a specially developed data processing scheme, the weak HCO3 signal is extracted from the strong sulfate signal background, hence a quantitative analysis with R-2 of 0.951 is made possible. Based on the spectra taken from deep sea seawater sampling, the concentration of HCO3 has been determined to be 1.91 mmol/L, with a relative error of 2.1% from the reported value (1.95 mmol/L) of seawater in the ocean. It is expected that the near-concentric cavity-enhanced Raman spectroscopy system could be developed and used for in-situ ocean observation in the near future.

• 出版日期2017-12
• 单位中国海洋大学