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On-line solid phase extraction and spectrophotometric detection with flow technique for the determination of nanomolar level ammonium in seawater samples
Citation
Chen, G and Zhang, M and Zhang, Z and Huang, Y and Yuan, D, On-line solid phase extraction and spectrophotometric detection with flow technique for the determination of nanomolar level ammonium in seawater samples, Analytical Letters, 44, (1-3) pp. 310-326. ISSN 0003-2719 (2011) [Refereed Article]
Copyright Statement
Copyright 2011 Taylor & Francis Group, LLC
DOI: doi:10.1080/00032719.2010.500775
Abstract
The determination of low-level ammonium in seawaters suffers from low sensitivity and high contamination; therefore, it is desirable to develop highly sensitive methods for automatic measurements. A highly sensitive and automated flow technique system for nanomolar level ammonium measurement is described. Reagents for Berthelot reaction were automatically added into seawater samples. After a 10 min reaction at 40°C, the formed indophenol blue compound was on-line extracted onto an Hydrophilic-Lipophilic Balance (HLB) cartridge. The enriched compound was rinsed with water and ethanol solution (30%, v/v) and, in turn, eluted with an eluent containing 30% (v/v) ethanol and 5.0 mM of NaOH, and determined with a spectrophotometer at 640 nm. Parameter, including extraction conditions, reagent concentrations, pH, temperature, and reaction time, were optimized. Under the optimized conditions, the detection limit was 3.5 nM and the linear range was 0–428 nM. The relative standard deviations were 5.7% (n = 8) for 44.6 nM standard solution and less than 6.0% (n = 3–5) for samples within concentrations of about 52.4–288.7 nM; the recovery was in the range 93.6 to 108.5%. The sample throughput was 3 h−1. The proposed method provides a simple, cheap, and automatic way to determine ammonium in seawater samples without complicated sample treatment.
Item Details
Item Type: | Refereed Article |
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Keywords: | ammonium, seawater, sequential injection, solid phase extraction |
Research Division: | Chemical Sciences |
Research Group: | Analytical chemistry |
Research Field: | Flow analysis |
Objective Division: | Environmental Management |
Objective Group: | Marine systems and management |
Objective Field: | Measurement and assessment of marine water quality and condition |
UTAS Author: | Zhang, M (Dr Min Zhang) |
ID Code: | 104697 |
Year Published: | 2011 |
Web of Science® Times Cited: | 30 |
Deposited By: | Chemistry |
Deposited On: | 2015-11-18 |
Last Modified: | 2018-03-17 |
Downloads: | 0 |
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