pH and buffering capacity problems involved in the determination of ammonia in saline water using the indophenol blue spectrophotometric method

Pai, Su‐Cheng; Tsau, Yung‐Jin; Yang, Tai-I

doi:10.1016/s0003-2670(01)00851-0

Cited by 171 publications

(94 citation statements)

References 8 publications

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“…SRP, DSi and NH 4 -N were measured based on the standard phospho-molybdenum blue, silicon molybdenum blue and indophenol blue [36] spectrophotometric procedures, respectively. NO 3 -N, NO 2 -N, and SRP were determined using an AA3 Auto-Analyzer (Bran+Luebbe Co., Germany) [35], while NH 4 -N and DSi were measured using a Tri-223 continuous Auto-Analyzer [35].…”

Section: Sampling and Analysesmentioning

confidence: 99%

Distribution, fluxes and decadal changes of nutrients in the Jiulong River Estuary, Southwest Taiwan Strait

et al. 2012

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The Jiulong River Estuary (JRE) is a typical subtropical macro-tide estuary on the southwest coast of the Taiwan Strait (TWS), which has been greatly impacted by human activities over the past 30 years. To understand nutrient dynamics and fluxes under such a heavy background of anthropogenic perturbation, eight cruises were conducted from April 2008 to April 2011, covering both wet (May to September) and dry (October to April next year) seasons. Nutrient concentrations were very high for the freshwater end-member in the upper reach of the JRE (nitrate (NO 3 In dry seasons, concentrations of these nutrients were higher than in wet seasons. Nitrate was the dominant chemical species of dissolved inorganic nitrogen (DIN), with percentages of 67%-96% in wet seasons and 55%-72% in dry seasons. Distributions of NO 3 -N and DSi against salinity were nearly constant during all cruises, and showed generally conservative mixing behaviors in the estuary (1

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Section: Sampling and Analysesmentioning

confidence: 99%

Distribution, fluxes and decadal changes of nutrients in the Jiulong River Estuary, Southwest Taiwan Strait

et al. 2012

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“…4. It was seen that the reduction peak current decreased significantly when NH 4 + was added into the solution (solid lines in Fig. 4).…”

Section: Cyclic Voltammograms Of Kbr In Presence Of Ammonium Ionmentioning

confidence: 94%

“…When the pH was raised, 2 bromine was hydrolyzed to hypobromous acid (HBrO) and further dissociated into hypobromite (BrO -), as were shown in equations (3), (4). The proportions of each product will depend on the pH of solution.…”

Section: Voltammetric Behavior Of Kbr In Aqueous Solutionmentioning

confidence: 99%

“…Table 1 summarized the equilibrium constants for equations (2) -(4). K 1 is the formation constant of tribromide in equation (2), K 2 is the hydrolysis constant for the equilibrium of equation (3) and K 3 is the dissociation constant of HBrO in equation (4). By rearranging equation (2) - (4) Fig.…”

Section: In-situ Uv-vis Spectra Of the Electrogenerated Brominementioning

confidence: 99%

“…The development of a sensitive and selective analytical method for the determination of ammonium ion is very important in the environmental evaluation of water pollution and fundamental to the understanding of nitrogen cycling in aquatic ecosystems. Indophenol blue spectrophotometry has been widely used for the determined in environmental waters because of the ease in operation and inexpensive equipment [4]. It involves the formation of the deep blue color of indophenol by reaction of ammonium ion with hypochlorite and phenol under alkaline conditions.…”

Section: Introductionmentioning

confidence: 99%

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Study on the Indirect Electrochemical Detection of Ammonium Ion with In Situ Electrogenerated Hypobromous Acid

2008

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The mechanism on the electrochemical oxidation of bromide in the presence of ammonium ion was studied by cyclic voltammetry and in-situ UV-Vis spectroscopy. The results indicated that the anodically generated bromine (Br 2 ) would be hydrolyzed to hypobromous acid (HBrO) at the pH range of 5 -7 and was further disproportionate to hypobromite anion (BrO -) when pH was large than 7. Both HBrO and BrO -were confirmed to be participated in the following homogeneous chemical reaction with the ammonium ion co-existed in the electrolytic solution. However, HBrO is electroactive whereas BrO -is electroinactive at carbon electrode. Based upon the reaction of HBrO with ammonium ion, an indirect electrochemical method was proposed for determination of ammonium ion at pH 7 with dual-electrode configuration, where HBrO was produced at a generator electrode and the excess HBrO was subsequently detected at a collector electrode after a reaction with ammonium ion. It was demonstrated that ammonium ion concentrations were proportional to the decreasing of reduction current at the collector electrode either in a batch solution or in a micro flow injection analytical (micro-FIA) system using an interdigitated array (IDA) Pt microelectrode and a carbon film ring-disk electrode (CFRDE), with the detection limit below 3 Μ. This approach shows the advantage of highly selectivity even in presence of a large amount of co-existed cations.

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The nonconservative property of dissolved molybdenum in the western Taiwan Strait: Relevance of submarine groundwater discharges and biological utilization

Wang

Xia

et al. 2016

Geochem Geophys Geosyst

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This study examined dissolved Mo and sedimentary Mo along with hydrochemical parameters in the western Taiwan Strait (WTS) in May and August 2012. The results demonstrate that dissolved Mo could be depleted of as high as 10–20 nM during our May sampling period when the nutrient‐enriched Min‐Zhe coastal current ceased and spring blooms developed. The negative correlation between Chl‐a and dissolved Mo suggests the possible involvement of high algal productivity in removing dissolved Mo out of the water column. Specific oceanographic settings (little currents) permitted a high sedimentary enrichment of Mo (>6 µg/g Mo) within the highly productive waters outside the Jiulong River mouth. Possibly, the high algal productivities and consequent organic matter sinks provide a pathway of Mo burial from water columns into sediments. Dissolved Mo was relatively high in groundwater samples, but we observed that submarine groundwater discharges (SGDs) only contributed to a relatively small percentage of the total dissolved Mo pool in WTS. It is probably attributable to the immediate removal of SGD‐released Mo ions via adsorption onto newly formed Mn oxides once exposed to oxygenated seawater, followed by an elevated sedimentary Mo accumulation near the SGDs (∼5 µg/g). In addition to metal oxide particle scavenging and sulfide precipitation, we estimated that biological uptake along with Mo adsorption onto organic matter carriers could finally provide more than 10% of the annual sedimentary Mo accumulation in WTS.

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pH and buffering capacity problems involved in the determination of ammonia in saline water using the indophenol blue spectrophotometric method

Cited by 171 publications

References 8 publications

Distribution, fluxes and decadal changes of nutrients in the Jiulong River Estuary, Southwest Taiwan Strait

Distribution, fluxes and decadal changes of nutrients in the Jiulong River Estuary, Southwest Taiwan Strait

Study on the Indirect Electrochemical Detection of Ammonium Ion with In Situ Electrogenerated Hypobromous Acid

The nonconservative property of dissolved molybdenum in the western Taiwan Strait: Relevance of submarine groundwater discharges and biological utilization

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