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

Sensors

Dewang Yang¹  Jinjia Guo¹  Ronger Zheng¹  Chunhao Liu¹  Qingsheng Liu¹ 

[1] College of Information Science & Engineering, Ocean University of China, Qingdao 266000, China;

关键词: laser Raman spectroscopy;    bicarbonate;    direct detection;    ocean application;   

DOI  :  10.3390/s17122784

来源: DOAJ

【 摘 要 】

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 R2 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.

【 授权许可】

Unknown