TY - CONF

T1 - Application of calibrated reagent-free spectrophotometry in determining nitrate in river water

AU - Vu, Ngoc Quynh

AU - Dietrich, Jörg

AU - Houben, Georg

PY - 2019

Y1 - 2019

N2 - Nitrate is a naturally occurring nitrogen compound, which can be found within environmental components like soil, water and plants. However, the excess amount of nitrate, which results from anthropogenic sources such as fertilizer use in agricultural production and wastewater, has led to water pollution and water quality degradation. Different methods have been developed over the past decades to determine and monitor nitrate in water bodies. One of the most widely-used methods can be listed as the spectrophotometry due to its rapidity, economy and simplicity. Recently, the spectrophotometric method has been improved with the approach of using no reagent in analysis for the sake of the environment and for cost saving. This study investigated the applicability and precision of the reagent-free spectrophotometry in determining the nitrate concentration of river water. The measured nitrate results from the tests had a tendency to be higher than the reference values which were obtained by ion chromatography. Two calibration methods were applied: the first method was two-point linear calibration; and the other was quantile mapping, a bias correction technique. Although two-point calibration is faster and simpler, quantile mapping is likely to generate better results: 72% of the results from two-point calibration method are within a deviation of ten percent from the reference values, while this number is 85% for quantile mapping method. These results support the applicability of reagent-free spectrophotometry with calibration techniques for on-site nitrate detection on the purpose of water quality research.

AB - Nitrate is a naturally occurring nitrogen compound, which can be found within environmental components like soil, water and plants. However, the excess amount of nitrate, which results from anthropogenic sources such as fertilizer use in agricultural production and wastewater, has led to water pollution and water quality degradation. Different methods have been developed over the past decades to determine and monitor nitrate in water bodies. One of the most widely-used methods can be listed as the spectrophotometry due to its rapidity, economy and simplicity. Recently, the spectrophotometric method has been improved with the approach of using no reagent in analysis for the sake of the environment and for cost saving. This study investigated the applicability and precision of the reagent-free spectrophotometry in determining the nitrate concentration of river water. The measured nitrate results from the tests had a tendency to be higher than the reference values which were obtained by ion chromatography. Two calibration methods were applied: the first method was two-point linear calibration; and the other was quantile mapping, a bias correction technique. Although two-point calibration is faster and simpler, quantile mapping is likely to generate better results: 72% of the results from two-point calibration method are within a deviation of ten percent from the reference values, while this number is 85% for quantile mapping method. These results support the applicability of reagent-free spectrophotometry with calibration techniques for on-site nitrate detection on the purpose of water quality research.

UR - https://www.researchgate.net/publication/334671209_Application_of_calibrated_reagent-free_spectrophotometry_in_determining_nitrate_in_river_water

M3 - Poster

T2 - International Interdisciplinary Conference on Land Use and Water Quality

Y2 - 3 June 2019 through 6 June 2019

ER -