Abstract-Probing the sulfur content in gasoline quantitatively with terahertz time-domain spectroscop

FangLi Qin, Qian Li, HongLei Zhan, WuJun Jin, HongLan Liu, Kun Zhao

http://pdfarticle.net/probing-the-sulfur-content-in-gasoline-quantitatively-with-terahertz-time-domain-spectroscopy/

Terahertz time-domain spectroscopy (THz-TDS) was used for the quantitative detection of sulfur content in gasoline. Models of chemo metrics methods and partial least squares (PLS) were built to measure THz-TDS and the sulfur content. All of the samples were divided into two parts. One part was used for calibration and the other one for validation. In order to evaluate the quality of the models, the correlation coefficient (R) and root-mean-square errors (RMSE) of calibration and validation models were calculated. The value of R and RMSE were close to 1 and 0 within acceptable levels, respectively, indicating that the combination of THz-TDS and PLS is a potential method for further quantitative detection

Abstract-Detecting NO 3 − concentration in nitrate solutions using terahertz time-domain spectroscopy

Qian Li, 

Honglei Zhan, 

Fangli Qin, 

Wujun Jin, 

Honglan Liu, 

Kun Zhao

http://link.springer.com/article/10.1007/s12200-014-0437-z
In this paper, we employed terahertz time domain spectroscopy (THz-TDS) to investigate the nitrate () concentration in four types of nitrate solution (sodium nitrate, aluminum nitrate, calcium nitrate and magnesium nitrate). Their absorption coefficient and refractive index were calculated in 0.2–2.5 THz, and a logarithmic relationship was observed between NO 3 −concentrations and selected optical parameters regardless of the kinds of nitrate solution. Partial least square (PLS) model was built between THz-TDS and NO 3 −concentration. The correlation coefficient of PLS model was calculated. The results make the quantitative analysis of NO 3 −concentration possible by THz-TDS and indicate the bright future in practical application.