Determination Of Nitrite In Water Research Articles

Gas chromatographic determination of nitrite in water by precolumn formation of 2-phenylphenol with flame ionization detection

Nitrite can be determined by its reaction with 2-aminobiphenyl in acidic medium to produce 2-phenylphenol which is quantified by gas chromatography with flame ionisation detection using biphenyl as an internal standard. The hydrolysis of the intermediate diazonium ion avoids many of the problems encountered in the conventional determination of nitrite by the diazotization of an aromatic amine (usually sulphanilamide) and coupling with N-(1-napthyl)ethylenediamine dihydrochloride to yield an azo dye followed by spectrophotometry. Unlike this method, the proposed reaction is rapid and does not suffer from interferences by copper(II), iron(III) and lead(II). The calibration graph was linear over the range 5–1000 μg/l NO 2-N and the limit of detection found to be 0.5 μg/l NO 2-N. A single analysis can be completed within 20 min. The method was not affected by coloured or turbid analyte solutions and has been used to determine nitrite in natural waters.

Kinetic Flow Injection Spectrophotometric Determination of Nitrite by its Catalytic Effect on the Oxidation of Chlorophosphonazo-pN by Bromate

Abstract A flow injection kinetic method has been developed for the determination of nitrite, based on its catalytic effect on bromate oxidation of chlorophosphonazo-pN in H2SO4 medium. The reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 551 nm. The sampling frequency was 83 h−1. The calibration curve was linear between 0.050 and 1.00 μg/ml, and the detection limit was 0.018 μg/ml. The proposed method was applied to the determination of nitrite in waters and soil with satisfactory results.

Fluorimetric Determination of Nitrite Using a New Reagent System

Abstract A simple and highly sensitive fluorimetric method for the determination of nitrite has been investigated. The method is based on the reaction of nitrite with tyrosine to form a highly fluorescent compound in alkaline medium. The calibration graph is linear in the concentration range of nitrite 4-200ng/ml with a detection limit 0.2ng/ml of nitrite. Interference due to other ions were studied to test the selectivity. The method was applied successful to the determination of nitrite in water and food samples.

HPLC fluorescence determination of nitrites in water using precolumn derivatization with 4-methyl-7-aminocoumarin

A rapid, simple, and sensitive method is described for determination of nitrites in water. Nitrite (NO2−) ions react with coumarin 120® (4-methyl-7-aminocoumarin) in sulfuric acid medium to give the corresponding 7-diazo compound. After hydrolysis, this latter yields (95%) the highly fluorescent 4-methyl-7-hydroxycoumarin (4-methylumbelliferone) which is fluorimetrically detected at 380 nm after excitation at 325 nm. In order to avoid interference from both excess coumarin 120® and the trace amounts of 4-methylumbelliferone which occurs in coumarin 120® as an impurity, use of HPLC is mandatory; a satisfactory separation is obtained on a cyano stationary phase with apolar hexane-isopropanol (95∶5, v/v) as eluent. Under these conditions, linearity of response is obtained from 1 to 30 μg.L−1 of NO2−; the limit of detection is 0.5 μg.L−1. The repeatability and reproducibility, expressed as RSD %, are 2.5 and 4.7 % respectively, for n=6 and 5 μg.L−, analytical characteristics which demonstrate the reliability of the proposed method.

Fluorimetric determination of nitrite

A sensitive and rapid fluorimetric method for the determination of nitrite is described. The method is based on the reaction of nitrite with tryptophan to form a highly fluorescent compound in alkaline medium. The method has been applied in the determination of nitrite in water and food samples.

Comparison of the simplex and Powell methods with a weighted response function for the optimization of FIA systems

An experimental comparison between the relative performances of the Powell and simplex methods for the optimization of a Flow Injection Analysis (FIA) system for the determination of nitrite in water is reported. An evaluation of the advantages of using a weighted linear combination of two variables (related to sensitivity and sample throughput rate) as the response function in the guidance of the optimization procedures towards different practical requirements is also included. Both methods proved to be effective for the optimization, none having shown definite advantages over the other. The use of a weighted response function in these optimization methods proved to be useful for assessing the versatility of FIA systems.

Kinetic-spectrofluorimetric determination of nitrite and nitrate at the nanograms per millilitre level by manual and flow-injection methods

The catalytic effect of nitrite on the oxidation of phenosafranine by bromate in acidic medium was studied by using the decrease in fluorescence intensity of phenosafranine. This kinetic—spectrofluorimetric method for nitrite is linear over the range 0.9–13.8 ng ml −1 with a relative standard deviation of about 1.5%. The method can be successfully adapted to flow-injection analysis in the stopped-flow mode. Manual and flow-injection methods were satisfactorily applied to the determination of nitrite in waters and meat products. The inclusion of a copperized cadmium column in the flow system allows the determination of nitrate and the sequential determination of nitrate and nitrite in mixtures.

Continuous flow determination of nitrite with membrane separation/chemiluminescence detection

A method for the determination of nitrite in water utilizing a membrane separation process and a chemiluminescence detector, with the addition of air-stripping and air-carrier, is proposed. The microporous poly(tetrafluoroethylene) tube was used as separator to transfer nitric oxide (reduced by iodine in acidic media) into a gas phase. Air-stripping was used to enhance the separation. Chemiluminescence signals produced from the reaction of nitric oxide with ozone were linearly proportional to the concentration of nitrite from 10 ppb (micrograms as N/L) to 5 ppm (mg N/L). The relative standard deviation (n = 5) was 0.7% at 0.1 ppm. The time elapse from starting the sample flow until the signal reached a stable level was 1.5 min.

ChemInform Abstract: A Rapid Spectrophotometric Method for the Determination of Nitrite in Water.

ChemInformVolume 21, Issue 4 Other Subjects ChemInform Abstract: A Rapid Spectrophotometric Method for the Determination of Nitrite in Water. D. P. S. RATHORE, D. P. S. RATHORE Chem. Lab., Reg. Centre Explor. Res., Atomic Minerals Div., Dep. Atomic Energy, Shillong-793012, IndiaSearch for more papers by this authorP. K. TARAFDER, P. K. TARAFDER Chem. Lab., Reg. Centre Explor. Res., Atomic Minerals Div., Dep. Atomic Energy, Shillong-793012, IndiaSearch for more papers by this author D. P. S. RATHORE, D. P. S. RATHORE Chem. Lab., Reg. Centre Explor. Res., Atomic Minerals Div., Dep. Atomic Energy, Shillong-793012, IndiaSearch for more papers by this authorP. K. TARAFDER, P. K. TARAFDER Chem. Lab., Reg. Centre Explor. Res., Atomic Minerals Div., Dep. Atomic Energy, Shillong-793012, IndiaSearch for more papers by this author First published: January 23, 1990 https://doi.org/10.1002/chin.199004310AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume21, Issue4January 23, 1990 RelatedInformation

A Rapid Spectrophotometric Method for the Determination of Nitrite in Water

A Rapid Spectrophotometric Method for the Determination of Nitrite in Water

Communication. Rapid determination of nitrite in water by flow injection with chemiluminescence detection

Communication. Rapid determination of nitrite in water by flow injection with chemiluminescence detection

Spectrophotometric determination of nitrite in water.

A sensitive and selective colour reaction for the determination of nitrite is presented. Nitrite reacts with p-aminophenylmercaptoacetic acid in the presence of hydrochloric acid to form a diazonium cation, which is subsequently coupled with N-(1-naphthyl)ethylenediamine dihydrochloride in acidic medium to form a stable bluish violet azo dye. The method is suitable for the determination of nitrite from 0.02 to 0.80 p.p.m. in a 1.0-cm cuvette. The observed molar absorptivity and Sandell's sensitivity of the azo dye are 4.65 × 104 l mol–1 cm–1 and 0.001 µg cm–2, respectively. The method is free from most interferences. The method has been applied to polluted water samples and the results obtained compare favourably with those from standard methods.

Spectrophotometric reaction-rate method for the determination of nitrite in waters with pyridine-2-aldehyde 2-pyridylhydrazone

A method for the kinetic determination of submicrogram amounts of nitrite has been developed, based on its acceleration of the rate of bromate oxidation of pyridine-2-aldehyde 2-pyridylhydrazone in acidic medium. The reaction is monitored spectrophotometrically at 372 nm. A comparative study with hydrochloric acid and perchloric acid media shows that the analytical parameters are affected by the type of acid used. Within-day precision, based on ten replicate determinations, was better than 0.011 μ/ml, which corresponds to 2.2-1.5% relative standard deviation at the concentrations examined. Application of this method in the determination of nitrite in water has been discussed. The recovery of nitrite from drinking waters ranges from 90 to 117% and the average relative standard deviation for nitrite determinations in polluted river water is 3.2%. Large amounts of nitrate and ammonium ions do not interfere. However, there is interference by Cu 2+, Pd 2+ and electroactive substances. Major advantages for the method are simplicity, absence of a reagent blank, and the wide determination range.

Spectrophotometric determination of nitrite in waters with 5,7-dihydroxy-4-imino-2-oxochroman.

La deviation relative standard est ±0,3% pour le dosage de 0,105 ppm de N nitrite. Application au dosage de nitrite dans des eaux de riviere, lac, pluie et dans des eaux usees

Kinetic determination of nitrite in waters by using a stopped-flow analyser

Automatic kinetic methods for the determination of nitrite in waters with a stopped-flow analyser are described. The methods are based on the diazotisation of sulphanilamide, the product being coupled with N-(1-naphthyl)-ethylenediamine dihydrochloride to form a highly coloured azo dye, which is measured at 540 nm. A single-point kinetic procedure uses a delay time of 10 s and one measurement of 0.7 s. A multi-point reaction rate method uses a delay time of 0.8 s and a measurement time of 1.5 s. The methods are fast, sensitive, accurate and precise, and without serious interference. The sample throughput for routine analysis can be up to 360 samples per hour in the range 0.025–2.00 p.p.m. of nitrite-nitrogen.

Spectrophotometric determination of nitrite in waters

Spectrophotometric determination of nitrite in waters

An improved flow injection determination of nitrite in waters by using intermittent flows

An injector—commutator with a 0:1:2 section is employed to achieve intermittent flows without intermittent pumping. The resulting flow injection system is very simple, manually operated, and requires only one peristaltic pump. When applied to the spectrophotometric determination of nitrite in waters, the device leads to an enhancement of the sensitivity and sampling rate without affecting other analytical characteristics. The merging zones approach is employed to decrease consumption of reagents.

Studies on Pollutants : A New Reagent for the Determination of Nitrite in Water

Studies on Pollutants : A New Reagent for the Determination of Nitrite in Water

The spectrophotometric determination of nitrite in water with 8-quinolinol

The method is based on the formation of a purple azoxine dye by coupling diazotized p-nitroaniline with 8-quinolinol. Beer's law is obeyed at 550 nm in the range 2–28 μg NO 2 - per 25 ml. The molar absorptivity and Sandell sensitivity are 3.88 × 10 4 l mol -1 cm -1 and 0.0012 μg cm -2, respectively.

Unexpectedly rapid esterification of nitrite applied to the determination of nitrite in water.

Unexpectedly rapid esterification of nitrite applied to the determination of nitrite in water.