Cation analysis of geothermal water samples with ion chromatography and spectroscopic methods

The aim of this study is to perform cation analysis of geothermal water samples with ion chromatography and spectroscopic methods.In the first part, simultaneous ion chromatographic analysis of six cations (lithium, sodium, ammonium, potassium, magnesium, and calcium) in geothermal water samples was performed by ion chromatography method. Some validation tests and the optimum conditions for the determination of cations were studied. The precision and accuracy of the method were tested at three different concentration levels for each standard. Recovery studies were performed by adding standards into the geothermal water and drinking water samples. Precision was also assessed as the percentage relative standard deviation of both repeatability (within-day) and reproducibility (between-day and different concentrations) for geothermal water samples. SD and RSD values of 320 geothermal water samples acquired during 12 months were evaluated.The second part consists of analysis of geothermal water samples by spectrophotometric method for manganese (II), zinc (II) and copper (II). The indicator dyes namely [5-phenylazo-8-quinolinol (A-8) and 5-(4-clorophenylazo)-8-quinolinol (A?13)] were offered for the first time for absorption based analysis of manganese (II), zinc (II) and copper (II). The indicator dyes were characterized in the different solvents of ethanol, dichloromethane, tetrahydrofurane and Toluene/Ethanol mixture (80:20)) and in solid matrix of PVC. Maximum absorption wavelength and molar extinction coefficients of the indicators were determined with UV-Vis spectrophotometer in all of the employed matrices. Cross sensitivities of the indicator dyes to other cations and anions was also tested and evaluated.