TY - JOUR
T1 - A greener alternative for inline nitrate reduction in the sequential injection determination of NOx in natural waters
T2 - replacement of cadmium reduction by UV radiation
AU - Machado, Ana
AU - Marshall, Graham
AU - Bordalo, Adriano A.
AU - Mesquita, Raquel B. R.
PY - 2017/3/28
Y1 - 2017/3/28
N2 - The use of sequential injection analysis (SIA) for key nutrient determination in water has been previously described using a copperised cadmium column to attain nitrate reduction to nitrite prior to determination, yielding hazardous waste. Here, a greener alternative is proposed for nitrate reduction using a UV lamp, aiming to avoid the use of cadmium. This method was based on the colorimetric Griess reaction for nitrite determination, after the UV reduction of nitrate. The reduction was performed inline during the determination of nitrite, minimizing both effluent production and the overall determination rate. Its application to natural waters, namely river water, proved to be effective as the results were comparable to those obtained with the reference procedure. Furthermore, certified reference samples were analysed, and an average of 3% relative deviation was observed. A limit of detection of 5.30 mM was achieved, enabling the nitrate determination in the dynamic range of 25-500 mM with a determination rate of 24 h(-1), and with a recovery percentage rate around 100%.
AB - The use of sequential injection analysis (SIA) for key nutrient determination in water has been previously described using a copperised cadmium column to attain nitrate reduction to nitrite prior to determination, yielding hazardous waste. Here, a greener alternative is proposed for nitrate reduction using a UV lamp, aiming to avoid the use of cadmium. This method was based on the colorimetric Griess reaction for nitrite determination, after the UV reduction of nitrate. The reduction was performed inline during the determination of nitrite, minimizing both effluent production and the overall determination rate. Its application to natural waters, namely river water, proved to be effective as the results were comparable to those obtained with the reference procedure. Furthermore, certified reference samples were analysed, and an average of 3% relative deviation was observed. A limit of detection of 5.30 mM was achieved, enabling the nitrate determination in the dynamic range of 25-500 mM with a determination rate of 24 h(-1), and with a recovery percentage rate around 100%.
UR - http://www.scopus.com/inward/record.url?scp=85036463608&partnerID=8YFLogxK
U2 - 10.1039/c7ay00261k
DO - 10.1039/c7ay00261k
M3 - Article
VL - 9
SP - 1876
EP - 1884
JO - Analytical Methods
JF - Analytical Methods
SN - 1759-9660
IS - 12
ER -