Quantitative Analysis of Ions in Spring Water in Three Different Areas of Hyogo Prefecture in Japan by Far Ultraviolet Spectroscopy

Far-ultraviolet (FUV) spectra in the 190 - 300 nm region were measured for spring water in Awaji-Akashi area, Tamba area and Rokko-Arima area in Hyogo Prefecture, Japan, these areas have quite different geology features. The spectra of the spring water in the Awaji-Akashi area can be divided into two groups: the spring water samples containing large amounts of NO3- and/or Cl-, and those containing only small amounts of NO3- and Cl-. The former shows a saturated band below 190 nm due to NO3- and/or Cl-. These two types of spectra correspond to different lithological areas: sedimentary lithology near the sea shore containing many ions in the seawater and gravitic lithology far from the sea side, in the Awaji-Akashi area. The spring water from the Tamba area, which is far from the sea, contains relatively small amounts of NO3- and Cl-; it does not yield a strong band in the region observed. The FUV spectra of three of four kinds of spring water samples in the Arima Hotspring show characteristic spectral patterns. They are quite different from the spectra of the spring water samples of the Rokko area. Calibration models were developed for NO3-, Cl-, SO42-, Na+, and Mg2+ in the nine kinds of spring water collected in the Awaji-Akashi area, Tamba, and Rokko-Arima area by using univariate analysis of the first derivative spectra and the actual values obtained by ion chromatography. NO3- yields the best results: correlation coefficient of 0.999 and standard deviation of 0.09 ppm with the wavelength of 212 nm. Cl- also gives good results: correlation coefficient of 0.993 and standard deviation of 0.5 ppm with the wavelength of 192 nm.