Spectrophotometric Determination of Ammonia in Estuarine Waters by Hybrid Reagent‐Injection Gas‐Diffusion Flow Analysis

Gray, Sarah M.; Ellis, Peter Smith; Grace, Mike; McKelvie, Ian D.

doi:10.1080/00387010600934766

Cited by 34 publications

(9 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Willason and Johnson [144], who were among the first to demonstrate the use of FIA for ammonia determinations in seawater, addressed this problem by the addition of citrate to complex these ions prior to gas diffusion. Gray et al [145], however, minimized the extent of Mg and Ca hydroxide precipitation prior to gas diffusion by the use of a hybrid reagent injection system in which microlitre volumes of base were injected into a continuous flow of sample. Watson et al [50] combined gas diffusion separation with the OPA-ammonia reaction and used fluorescence detection to achieve very low detection limits (7 nM) for ammonia determination in seawater (see Table 3).…”

Section: Ammoniummentioning

confidence: 99%

Flow injection analysis as a tool for enhancing oceanographic nutrient measurements—A review

Worsfold

Clough

Lohan

et al. 2013

Analytica Chimica Acta

Self Cite

View full text Add to dashboard Cite

Section: Ammoniummentioning

confidence: 99%

Flow injection analysis as a tool for enhancing oceanographic nutrient measurements—A review

Worsfold

Clough

Lohan

et al. 2013

Analytica Chimica Acta

Self Cite

View full text Add to dashboard Cite

“…At pHo8.75 [3], the predominant ammonia species is the ammonium ion (NH 4 þ ). Since all experiments were performed at pHr7, all ammonia concentrations are expressed as mg L À 1 NH 4 þ , although a small amount of molecular ammonia was also present.…”

Section: Reagents and Solutionsmentioning

confidence: 99%

“…below 8.75), within the concentration range usually found in environmental waters (e.g. 0.03-17.5 mg L À 1 NH 4 þ [3]). Dinonylnaphthalene sulfonic acid (DNNS), used as a commercial sulfonic acid-based extractant that facilitates the transport of cations ( Fig.…”

Section: Introductionmentioning

confidence: 97%

A study of the ammonium ion extraction properties of polymer inclusion membranes containing commercial dinonylnaphthalene sulfonic acid

Almeida

Silva

Cattrall

et al. 2015

Journal of Membrane Science

View full text Add to dashboard Cite

“…The direct determination of NH 4 + has been investigated, including optical biosensors with a 5-μM limit of detection (LOD) (Azmi et al, 2009) and ion selective electrodes with 1.6-μM LOD (Eaton et al, 2005). Other NH 4 + detection methods/analyzers have also been summarised (MeseguerLloret et al, 2002;Gray et al, 2006), with the reported LOD improved down to 14 nM using a flow injection gas diffusion spectrophotometry-based analyzer. Recent work (Plant et al, 2009) has demonstrated an in situ analyser with a LOD of 10 nM.…”

Section: Introductionmentioning

confidence: 98%

A high-resolution analyser for the measurement of ammonium in oligotrophic seawater

et al. 2011

View full text Add to dashboard Cite

In this work, we describe a high-resolution fluorometric shipboard analyser and an improved method to determine NH 4 + in oligotrophic seawater. The limit of detection is <5 nM, calculated with 95% confidence level using the weighted regression line applied to the standard addition method using real samples prepared with low nutrient seawater from the Atlantic. The results are summarised and cross-compared with spiked artificial seawater (ASW) and spiked Milli-Q water samples. The analyser has a precision of ±1-4% with a high performance over a wide range from 5 nM to 25 μM. The methodology of NH 4 + analysis is based on the fluorescent product formed between o-pthaldialdehyde and NH 4 + in the presence of sulfite. Due to the high resolution of the developed system, we were able to study in depth the sensitivity of the method to salinity, amines, amino acids and potential interferences from particles/algae. The method was found to be sensitive to salinity variations, reducing the signal by up to 85% at 5 nM; this effect decreased at higher concentrations of ammonium. It was noted that the interference from amines at low concentrations was negligible; however, at either high amino acid or high amine concentrations, the signal was depressed. To test for the effect of particles on the system, the system was tested with samples containing phytoplankton (Dunaliella primolecta) cells at different concentrations prepared with ASW to simulate the effect of a phytoplankton bloom. This experiment assessed the potential impact of both particles and other potential fluorescence interferences from cells and/or ammonium leaching from cells. This experiment showed that a phytoplankton bloom could potentially have an impact of up to 12% on the signal of interest. Thus, we propose that this method is suitable for oligotrophic environments rather than coastal and eutrophic environments. The reagent was found to be stable for 17 days and standards of 1 μM were stable for 6 days under laboratory conditions. The developed analyser was successfully demonstrated in the North Atlantic Ocean, in an area of oligotrophic, low NH 4 + oceanic waters.

show abstract

Spectrophotometric Determination of Ammonia in Estuarine Waters by Hybrid Reagent‐Injection Gas‐Diffusion Flow Analysis

Cited by 34 publications

References 21 publications

Flow injection analysis as a tool for enhancing oceanographic nutrient measurements—A review

Flow injection analysis as a tool for enhancing oceanographic nutrient measurements—A review

A study of the ammonium ion extraction properties of polymer inclusion membranes containing commercial dinonylnaphthalene sulfonic acid

A high-resolution analyser for the measurement of ammonium in oligotrophic seawater

Contact Info

Product

Resources

About