Nitrate photometric determination

In this development of a flow injection method for the determination of nitrate andnitrite, Anderson [168] chose the Shinn [155] method to reduce nitrate and nitrite because of its high sensitivity and relative freedom from interferences. Anderson [168] used flow injection in the photometric determination of nitrite and nitrate with sulfanilamide and N-( 1-naphthyl) ethylenediamine as reagents, as discussed next. The detection limit is 0.05 xm for nitrite and 0.1 xm for nitrate at a total sample volume of 200 iL. Up to 30 samples can be analysed per hour with relative precision of about 1%. 

Polyphosphonic acids can be separated on a special latex-based anion exchanger. They are photometrically determined after complexation with ferric nitrate [27] (see Section 3.3.5.2). This method enables a qualitative analysis of inorganic and organic phosphates that are contained in conditioners. Fig. 8-27 illustrates this with the chromatogram of a commercial product. Clearly, it is a multicomponent mixture with two main components and several minor components. 

Peak smoothing is also an option, as demonstrated in the spectro-photometric determination of nitrate and nitrite [93]. The signals recorded for the blank and the sample were processed by applying a simple algorithm, allowing the blank signal to be subtracted. Analytical repeatability, however, was impaired due to the error propagation effects involved. 

For the photometric determination of nitrates their reaction with brucine... 

In addition to the absorption photometric determination of nitrates in the visible region, absorption spectrophotometric methods in the UV region are also used. This method is one of the standard methods, e.g. [13, 32], but it is recommended only for very pure waters (drinking or unpolluted natural waters) [50, 51]. 

The pharmacopoeia test is quite unique in that a content of nitrate under the conditions given will react with nitrobenzene to give m-dinitrobenzene, which then will react with acetone to form a colored product indication a positive reaction. The methodology of this second reaction was first described in literature in 1939 by Pesez and is based on the Janovsky reaction that for many years was widely used for the colorimetric/photometric determination of substances sometimes referred to as methyl ketones. ... 

Photometric determination of nitrate with 2,6-dimethylphenol is conducted in accordance with the German Standard Methods and/or in accordance with DIN 38403, Part 9. In a sulphuric or phosphoric acid solution, nitrate ions react to this reagent within approximately 3 minutes to produce yellowish-coloured 4-nitro-2,6-dimethylphenol. 

Phosphorus has been determined [23, 24] in thermally stable polymers by mineralisation with a nitric - perchloric acid mixture and subsequent titration with lanthanum nitrate or by photometric determination of the phosphomolybdic blue complex. 

M.A. Feres, B.F. Reis, A downsized flow set up based on multicommutation for the sequential photometric determination of iron(II)/iron(III) and nitrite/nitrate in surface water, Talanta 68 (2005) 422-428. 

Matthews and Riley [99] preconcentrated iodide by co-precipitation with chloride ions. This is achieved by adding 0.23 g silver nitrate per 500 ml of seawater sample. Treatment of the precipitate with aqueous bromine and ultrasonic agitation promote recovery of iodide as iodate which is caused to react with excess iodide under acid conditions, yielding I3. This is determined either spectrophotometrically or by photometric titration with sodium thiosulfate. Photometric titration gave a recovery of 99.0 0.4% and a coefficient of variation of 0.4% compared with 98.5 0.6% and 0.8%, respectively, for the spectrophotometric procedure. 

HMX on a Semi-Plant Scale , PATR 2183 (1955) (Conf, not used as a source of info) 20) D.E. Seeger et al, "Preliminary Investigation of HMX and Medina for Use in Detonators , PATR 2245 (1956) (Conf, not used as a source of info) 21) P. N. Lensi et al, PATR 2326 (1956) (Conf, not used as a source of info) 2) T.M. Finnie H.J. Yallop, Anal 82, 653 (1957) (Application of DPhA related compds to spot-tests for nitrate nitramine expls) 23) R- Robbins, "The Preparation, Properties and Uses of HMX , Holston Defense Corp Control Rept RR-GC-149 (1958) 24) W. Jeffers, ERDE Rept l/R/58 (1958) (Conf, not used as a source of info) 25) S. Semel et al, AnalChan 31, 1050-52 (1959)(Colorimetric determination of RDX HMX) 26) F. Pristera et al, "Infrared Spectro-photometric Method for Determining Alpha Gamma Polymorphs in Beta HMX, PicnArsn Rept FRL-TR 19 (I960) 26a) C.C. Jamison, "Determination of... 

Fig. 3. Trace determination of some inorganic and organic anions in pure water, after an electrophoretic enrichment at 5 kV for 45 s with an addition of 75 p,M octanesulfonate to the sample [42]. The electrolyte 10 mM sodium chromate and 0.5 mM OFM-BT (a surfactant used as the EOF modifier), adjusted to pH 8 with sulfuric acid 15 kV 60 cmX75 fjim I.D. capillary, distance to detector, 52 cm UV photometric detection at 254 nm. Anions (concentrations in mg/1) 1, chloride (3.5) 2, sulfate (4.8) 3, nitrate (6.2) 4, oxalate (5) 5, fluoride (1.9) 6, formate (5) 7, phosphate (3.2) 8, acetate (5) 9, propionate (5).

Calibration solutions of cadmium and lead have been prepared from high purity (higher than 98%) cadmium and lead nitrate dissolved in nitric acid. A high accuracy titration method (EDTA complexometry reaction with photometric detection) was used to determine the final... 

Two colorimetric methods are recommended for boron analysis. One is the curcumin method, where the sample is acidified and evaporated after addition of curcumin reagent. A red product called rosocyanine remains it is dissolved in 95 wt % ethanol and measured photometrically. Nitrate concentrations >20 mg/L interfere with this method. Another colorimetric method is based upon the reaction between boron and carminic acid in concentrated sulfuric acid to form a bluish-red or blue product. Boron concentrations can also be determined by atomic absorption spectroscopy with a nitrous oxide—acetylene flame or graphite furnace. Atomic emission with an aigon plasma source can also be used for boron measurement. 

For the determination of nitrates at concentrations > 0.5 mg the photometric method with sodium salicylate is used. It is based on the reaction of NO3 with sodium salicylate in the presence of trichloroacetic or sulphuric acid. After alkalization yellow salts of nitrosalicylic acid are formed ... 

B. C. Madsen, Utilization of Flow Injection with Hydrazine Reduction and Photometric Detection for the Determination of Nitrate in Rain-Water. Anal. Chim. Acta, 124 (1981) 437. 

The nitrogen contained in organic substances in water is converted to ammonium ions by KjeldahEs decomposition method. The ammonium ions are distilled from alkaline solution as ammonia, collected in boric acid solution and determined acidimetrically or photometrically in the receiver. Ammonium ions originally contained in the sample are separated, identified and deducted, or separated off by distillation before carrying out the Kjeldahl decomposition. Nitrite and nitrate are volatilized by H2SO4 in the... 

Nitrate and nitrite The nitrate and nitrite content of cheeses that have been treated with these salts can be determined by reduction with cadmium followed by reaction with sulfonamide and N-l,nap-hthylethylenediamine hydrochloride. This produces a colored compound that can be quantified spectro-photometrically. 

Patton, C. J., A. E. Fischer, W. H. Campbell, and E. R. Campbell. 2002. Corn leaf nitrate reductase A nontoxic alternative to cadmium for photometric nitrate determinations in water samples by air-segmented continuous-flow analysis. Environ. Sci. Technol. 36 729-735. 

Several tests that could not be carried out in the field were completed in the laboratory within five hours after the samples were collected. These included chemical oxygen demand (COD), which was determined photometrically after oxidation of the oombustible organic material in chromate sulfuric add in the presence of silver sulfate. The nitrate concentration was calculated from the nitrite concentration determined photometrically employing the Griess Reaction after the reduction of the nitrate to nitrite by metallic cadmium. The nitrite-N concentration determined in the field was subtracted 6om the result to calculate the nitrate-N content of the water, which was then converted to the nitrate concentration by multiplication. Fluoride was determined photometrically based on the decoloration of Spadns reagent. 

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