A simple method for determining water content in organic solvents based on cobalt(II) complexes

A method to determine water content in organic solvents was developed based on the color change of cobalt(II) nitrate in different solvents. The color-change mechanism and optimal conditions for determining the water content were investigated. The results showed that there was a good linear relationships between the absorbance of cobalt(II) complexes in organic solvents and water contents with γ in 0.9989∼0.9994. This method has the advantages of low cost, good reproducibility, good sensitivity, simple in operation, fast in detection, friendly to the environment and no limitation on linear range for determining water content. It was used to determine water in samples with a satisfactory recovery in 97.81%∼101.24%.