Online zinc reduction-sequential injection analysis for the determination of nitrogen species in extracts of riverine sediment

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Date
2017-04-07
Authors
Oladosu, N. O.
Abayomi, A. A.
Zhang, X.
Olayinka, K. O.
Alo, B. I.
Deng, A.
Journal Title
Journal ISSN
Volume Title
Publisher
Springer
Abstract
The substitution of hazardous analytical reagents such as Cd with benign alternatives for chemical determination is one of the principles of green chemistry. An eco-friendly Zn reduction method for nitrate determination was developed to achieve this end. Online zinc reduction-sequential injection analysis (ZnR-SIA) protocol was developed for the determination of nitrogen (N) species in the Lagos Lagoon sediments by modification of some standard methods. The novel application of boric acid-borate buffer employed in borate-buffered granular Zn reduction suppressed gas evolution from the Zn micro-column, making the Zn reduction adaptable to online use, unlike the frequently used ammonia-ammonium buffer. Further results showed that the sampling rate for the two-zone stack was 65 h−1. The boric acid-borate buffer offered 5.9-fold and 1.3-fold of the instrument response given by the ammonia-ammonium buffer at 0.50 and 5.0 mg N L−1 respectively. The method detection limits of the ZnR-SIA for the three matrices studied were 24.6 μg N L−1 for reagent water, 0.383 mg N kg−1 for KCl-extractable nitrate, and 3.18 mg N kg−1 for total nitrogen. The average recovery of nitrate-N in matrix samples was 94.7%, and its precision was 4.52%. The average recoveries of total N in blanks and matrix samples were 97.9 and 93.2% respectively. The method accuracies demonstrated the suitability of the ZnR-SIA for sediment N determination. Zn reduction is recommended where sustainable development is desired and is a potential substitute for the standard Cd reduction owing to Cd toxicity.
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Keywords
Research Subject Categories::NATURAL SCIENCES::Chemistry::Analytical chemistry::Separation methods , Zn reduction method , boric acid-borate , ammonia-ammonium buffer , Lagos Lagoon , sediments
Citation
Oladosu, N. O., Abayomi, A. A., Zhang, X., Olayinka, K. O., Alo, B. I., & Deng, A. (2017). Online zinc reduction-sequential injection analysis for the determination of nitrogen species in extracts of riverine sediment. Journal of Analytical Science and Technology, 8(1), 5.