Nitrate Interference Research Articles

Mutual interference of ammonium, nitrate, and urea on uptake of 15N sources by the marine diatom Skeletonema costatum (Grev.) Cleve

14N- and 15N-labelled ammonium, urea, and nitrate were used to determine mutual influence effects on uptake in Skeletonema costatum (Grev.) Cleve. The following combinations of N sources showed mutual interference on uptake rates: ammonium on nitrate, ammonium + urea on nitrate, urea on ammonium, nitrate + urea on ammonium, nitrate on urea, ammonium on urea, and ammonium + nitrate on urea, whereas there was no mutual interference of nitrate on ammonium and of urea on nitrate. In all cases, but one, the uptake rates were constant throughout the incubation period. The uptake rate of nitrate, with the simultaneous addition of ammonium + urea, decreased in a hyperbolic manner with time. The summed uptake rates for an oxidized (nitrate) and a reduced N source (urea, ammonium) greatly exceeded the uptake rate necessary to maintain the preconditioned growth rate, whereas the summed uptake rate of two reduced N sources exceeded this maintenance rate to a lesser degree. The experiments were begun immediately before the preconditioned cells had used the available nitrate. A model is described whereby the uptake of 15N can be calculated in uptake experiments, where the initial amount of cellular N is known instead of the final, and where there is a simultaneous uptake of other (unlabelled) N sources.

Ultraviolet spectrophotometric determination of gadolinium in concentrated solutions of nitrate salts

Ultraviolet spectroscopy was successfully applied for determining the gadolinium concentration in Gd(NO/sub 3/)/sub 3/ solutions. The /sup 6/I/sub 15/2/, /sup 6/I/sub 13/2/ reverse arrow /sup 8/S/sub 7/2/ transitions of the Gd/sup 3 +/ ion, which are responsible for the fine structure at 272.8 nm, were selected as a basis for the investigation of three analytical modes, one based on three wavelength measurements (mode ABS) and the others on first- and second-derivative measurements (modes deltaA/deltalambda and delta/sup 2/A/deltalambda/sup 2/). For the particular problem concerned here, namely, to deal with nitrate interference in the spectral region of interest (270-280 nm), the best performance was shown by the first-order derivative mode, which had a precision of +- 0.035 g L/sup -1/, a discrimination limit of 0.071 g L/sup -1/, and an accuracy of 0.60% for an 8 g L/sup -1/ Gd solution. This study shows that it is possible to adopt this principle for quantitative analysis of the Gd(NO/sub 3/)/sub 3/ solutions (0.0509 M or 8 g L/sup -1/ Gd) used in the emergency shutdown systems of CANDU-PHW (Canada deuterium uranium-pressurized heavy water) reactors. 19 references, 4 figures, 2 tables.

A comparison of nitric acid and particulate nitrate measurements by the penetration and denuder difference methods

Measurements of ambient nitric acid and particulate nitrates were made by the dual-filter, denuder difference and penetration methods for 53 days during the summer of 1981 in Warren, Michigan. Nitric acid average concentrations determined by the penetration method (3.71 μg m −3) and the denuder difference method (3.11 μg m −3) were significantly lower than the dual-filter measurements (4.52 μg m −3). Similarly, nonvolatile particulate nitrate averaged 0.95 μg m −3 by penetration and 1.10 μg m −3 by denuder difference compared to 1.53 μg m −3 by the dual-filter method. These comparisons indicated that the penetration and denuder difference methods achieve significant reductions in nitric acid and nonvolatile particulate nitrate interferences. Based upon its operational simplicity, the denuder difference method is recommended.

Elimination of nitrate interference in the determination of platinum in some animal tissues using furnace atomic absorption spectrometry

Elimination of nitrate interference in the determination of platinum in some animal tissues using furnace atomic absorption spectrometry

Interference of nitrate in the determination of formaldehyde by the chromotropic acid method

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInterference of nitrate in the determination of formaldehyde by the chromotropic acid methodElizabeth L. R. Krug and William E. HirtCite this: Anal. Chem. 1977, 49, 12, 1865–1867Publication Date (Print):October 1, 1977Publication History Published online1 May 2002Published inissue 1 October 1977https://doi.org/10.1021/ac50020a059RIGHTS & PERMISSIONSArticle Views171Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (372 KB) Get e-Alerts Get e-Alerts

Observations on the bismuth sulfide colorimetric procedure for sulfate analysis in soil

Abstract The bismuth sulfide and methylene blue colorimetric finishes for soil sulfate determination by the Johnson‐Nishita distillation method were examined and compared. Both procedures gave comparable results when applied to soils and soil extracts, but the bismuth method was more rapid and more reliable. Nitrogen flow rate over the range 100–500 ml/min was not critical for the bismuth method, provided appropriate distillation times were employed. However, the release and transfer of hydrogen sulfide in the bismuth method was effected in one‐third of the time required for the methylene blue finish, largely due to the elimination of a gas‐washing step. Predrying of soil extract samples increased recovery of hydrogen sulfide with the bismuth procedure arid could be used to increase sensitivity. Nitrate interference was observed with the bismuth procedure but attributed to interference during the reduction step. The bismuth procedure can readily be adapted for microdetermination in the 0–40 ppm sulfate‐S ...

Elimination of nitrate interference in the trace détermination of sulphate as hydrogen sulphide

The microdetermination of sulphate by reduction to hydrogen sulphide, determined colorimetrically as Methylene Blue, is subject to interference from nitrate ion. This interference is eliminated by adding zinc acetate and igniting samples at 320° for one hr.

An automated method for the determination of boron in sewage, sewage effluents and river waters

An automated method for the determination of boron in sewage, sewage effluents and river waters on the Technicon AutoAnalyzer is described. The reaction of carminic acid with boron in concentrated sulphuric acid is used. The limit of detection is about 0·02 mg l–1 of boron and the standard deviation is ±0·03 mg l–1 at concentrations of 3·0 mg l–1 of boron. The interference of nitrate and its suppression by the use of phenol are examined.

A simple diffusion method for the determination of fluoride

A method is described for the determination of sub-microgram amounts of inorganic fluoride. Diffusion on to a thin layer of solid alkali is used to separate fluoride from any contaminants. The diffused fluoride may be determined with an ion-selective fluoride electrode or by spectrophotometric methods.Phosphate and sulphate do not interfere. The interference of halides, carbonate, nitrate and acetate is discussed. Organic material was found not to interfere with the recovery of fluoride except in determinations involving human serum. High-temperature ashing of organic samples was found to lead to loss of fluoride.When used with the ion-selective electrode the method is applicable over the range 0·05 to 200 µg of fluoride.

The sequence of elution of plant organic acids from silica gel chromatographic columns

The sequence of emergence of 39 plant and related acids from silica gel chromatographic columns by gradient elution with chloroform- n-butanol mixtures is described. The interference of nitrate in the determination of several acids and, most importantly, malic and citric is reported. The effect of structural relationships such as chain length, number of carboxyl, hydroxyl or keto groups and cis and trans isomerisation on the volume of solvent required for elution is discussed.

Volumetric determination of styphnates with methylene blue

A modification of Bolliger's extraction titration of o-polynitrophenols with methylene blue is described. Because of its better solvent power, nitrobenzene has been used as the extracting agent instead of chloroform, which would necessitate repeated renewal during the titration. The method is applied to the determination of lead styphnate and of the intermediates and effluents in its production, as well as to the analysis of priming compositions. Nitrate interference is removed by extracting the styphnic acid with isobutyl methyl ketone before the titration.

Interference of nitrate and nitrite in the iron-sulfuric acid cholesterol reaction

Interference of nitrate and nitrite in the iron-sulfuric acid cholesterol reaction

Extraction-Flame Photometric Determination of Boron.

Submilligram quantities of boron were completely extracted from aqueous solution into methyl isobutyl ketone as the tetrabutylammonium boron -- tetrafluoride ion association complex. The boron content of the separated organic phase was determined by direct flame spectrophotometric analysis, using an oxygen-sheathed oxyhydrogen flame as the excitation source. Of 30 metal ions studied, only five interfered at a l to 1 mole ratio to boron. Interfering anions were phosphate, perchlorate, and high levels of nitrate. Nitrate interference was eliminated by suifuric acid fuming prior to extraction. (auth)