Determination of nitrate and nitrite in seawater by flow injection analysis1

Johnson, Kenneth S.; Petty, Robert L.

doi:10.4319/lo.1983.28.6.1260

Cited by 136 publications

(54 citation statements)

References 6 publications

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“…Nitrate and nitrite were measured by standard colorimetric methods (Johnson and Petty, 1983). Phosphate was determined using a colorimetric method described elsewhere (Eibl and Lands, 1969).…”

Section: Analysis Of Nutrient Alkalinity and Dissolved Inorganic Camentioning

confidence: 99%

Responses of Nannochloropsis oceanica IMET1 to Long-Term Nitrogen Starvation and Recovery

et al. 2013

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The Nannochloropsis genus contains oleaginous microalgae that have served as model systems for developing renewable biodiesel. Recent genomic and transcriptomic studies on Nannochloropsis species have provided insights into the regulation of lipid production in response to nitrogen stress. Previous studies have focused on the responses of Nannochloropsis species to short-term nitrogen stress, but the effect of long-term nitrogen deprivation remains largely unknown. In this study, physiological and proteomic approaches were combined to understand the mechanisms by which Nannochloropsis oceanica IMET1 is able to endure long-term nitrate deprivation and its ability to recover homeostasis when nitrogen is amended. Changes of the proteome during chronic nitrogen starvation espoused the physiological changes observed, and there was a general trend toward recycling nitrogen and storage of lipids. This was evidenced by a global down-regulation of protein expression, a retained expression of proteins involved in glycolysis and the synthesis of fatty acids, as well as an up-regulation of enzymes used in nitrogen scavenging and protein turnover. Also, lipid accumulation and autophagy of plastids may play a key role in maintaining cell vitality. Following the addition of nitrogen, there were proteomic changes and metabolic changes observed within 24 h, which resulted in a return of the culture to steady state within 4 d. These results demonstrate the ability of N. oceanica IMET1 to recover from long periods of nitrate deprivation without apparent detriment to the culture and provide proteomic markers for genetic modification.

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Section: Analysis Of Nutrient Alkalinity and Dissolved Inorganic Camentioning

confidence: 99%

Responses of Nannochloropsis oceanica IMET1 to Long-Term Nitrogen Starvation and Recovery

et al. 2013

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“…Weights of between 5 and 50 mg were used, depending on nitrogen content. We used a 20/20 Europa Scientific ANCA-SL mass spectrometer to measure percent nitrogen content and at.% 15 N. The water samples were analysed for nitrate plus nitrite (Johnson 1983), and ammonium (Switala 1993 The last factor provided correction for the 15 N enrichment of the addition solution (15 at.% 15 N). The mean total N incorporation of the 4 replicate cores was then calculated.…”

Section: We Added Inorganicmentioning

confidence: 99%

The role of benthic vegetation as a sink for elevated inputs of ammonium and nitrate in a mesotrophic estuary

Dudley¹,

Gahnström²,

Walker³

2001

Mar. Ecol. Prog. Ser.

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“…The greatest residence time in the Lachat nitrate chemistry manifold is due to the reduction column, but Johnson and Petty (1983) showed that the reduction of nitrate to nitrite was nearly 100% complete with column residence times of only about 1 s; the large volume of the standard Lachat reduction columns is an obvious volume to minimize. It is straightforward to simply build a smaller column with Cd powder but this has several limitations.…”

Section: Materials and Proceduresmentioning

confidence: 99%

“…Nitrate analysis follows a modification of this method by Johnson and Petty (1983); briefly, samples are injected into a carrier stream through an injection valve and then buffered to pH ≥ 8 with an imidazole buffer rather than the ammonium chloride used previously (Grasshoff 1983;Johnson and Petty 1983). Nitrate in the sample is reduced to nitrite in a column packed with copperized cadmium granules.…”

mentioning

confidence: 99%

High‐frequency measurement of seawater chemistry: Flow‐injection analysis of macronutrients

Hales

Geen

Takahashi

2004

Limnology & Ocean Methods

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We adapted a commercially available flow-injection autoanalyzer (Lachat Quik-Chem 8000) to measure seawater nitrate concentrations at a rate of nearly 0.1 Hz and phosphate and silicate concentrations at a rate half that. Several minor improvements, including reduced sample-loop size, high sample flushing rate, modified carrier chemistry, and use of peak height rather than peak area as a proxy for nutrient concentration aided in the increase in sampling rate. The most significant improvement, however, was the construction of a copperized cadmium NO 3 -reduction column that had a high surface area to volume ratio and a stable packing geometry. Preliminary results from a cruise in the Ross Sea in austral spring of 1997 are shown. Precision of all three analyses is better than 1%. Comparison of the nutrient concentrations determined by the rapid analysis method described here with traditional discrete analyses shows that nitrate and silicate determined by the two approaches are within a few percent of each other, but that the phosphate concentrations determined by the rapid analysis are as much as 10% lower than those determined by the discrete analyses.

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Determination of nitrate and nitrite in seawater by flow injection analysis1

Cited by 136 publications

References 6 publications

Responses of Nannochloropsis oceanica IMET1 to Long-Term Nitrogen Starvation and Recovery

Responses of Nannochloropsis oceanica IMET1 to Long-Term Nitrogen Starvation and Recovery

The role of benthic vegetation as a sink for elevated inputs of ammonium and nitrate in a mesotrophic estuary

High‐frequency measurement of seawater chemistry: Flow‐injection analysis of macronutrients

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