New development of optical fibre sensor for determination of nitrate and nitrite in water

A novel ultraviolet optical fibre sensor is developed for the determination of nitrate and nitrite in water samples. The absorptivity spectra of nitrate and nitrite are determined at analytical wavelengths of 302 nm and 356 nm. Nitrate and nitrite are measured in the concentration range from 0.0 mg/L to 50 mg/L. The obtained results indicate that a linear relationship between the absorbance with the concentration of nitrate and nitrite in water. The other chemical species present in water do not much interfere with ultraviolet absorbance measurement of nitrate and nitrite. Detection limits are investigated by optical fibre sensor for nitrate is 0.0017 mg/L and nitrite is 0.0014 mg/L. Regression equations for the determination of nitrate and nitrite are presented and successful applied which require the determination concentration nitrate and nitrite in environmental water samples.