Spectrophotometric Determination Of Cyanide Research Articles

Spectrophotometric Determination of Cyanide in Passaic River Paterson New Jersey by Distillation and Colorimetric Method with Pyridine: Barbituric Acid Reagent

Purpose: This work determines the concentration of total cyanide in the Passaic River in the New Jersey Area.
 Methodology: The concentration of cyanide and the subsequent reaction of the product with a mixed solution of pyridine-barbituric acid to form a stable complex. Therefore, before chlorination of cyanide, all cyanide compounds present in sample must be broken down by an acid reflux and distillation.
 Findings: The cyanide concentration in the Passaic River sediment solution and non-running wastewater was determined by measuring absorbance at max 578 nm, and cyanide amount has been found less than 0.005 ppm under the NEPA permit compliance. Industrial facilities who discharge wastewater to public waterways in the United States, stringent limits on cyanide, typically with monthly average effluent limits set around 0.005 ppm or less.
 Unique contributor to theory, policy and practice: This method is applicable to the determination of cyanide in drinking, saline, groundwater, surface water as well as domestic and industrial wastewater.

Spectrophotometric Determination of Cyanide Based on Berthelot Reaction

The proposed spectrophotometric method for the determination of cyanide involves conversion of cyanide to cyanate using sodium hypochlorite followed by acid hydrolysis to form ammonium sulphate. The formed ammonium sulphate is determined based on Berthelot reaction using salicylic acid, sodium hypochlorite, and sodium nitroprusside. The λmax for the formed dye is at 648 nm and the calculated molar absorptivity is 1.8 × 104 L mol−1 cm−1. Beer's law is obeyed in the concentration range 0–5 µg and the relative standard deviation is 2.2% for n = 10 at 0.3 ppm of CN−. The developed method was applied for the determination of cyanide in the hypochlorite/H2O2 treated electroplating effluents and sludges. The results obtained in the developed method compares well with the pyridine–barbituric acid method and by recovery studies of added cyanide.

Selective determination of gases by two-stage membrane-differentiated flow injection analysis. Determination of trace hydrogen cyanide in the presence of large concentrations of hydrogen sulfide

Hydrogen cyanide at low ppbv levels is determined in the presence of several thousand ppmv H 2 S. The gases diffuse through a porous poly(vinylidene difluoride) (PVDF) tubular membrane into an NaOH absorber; the pH is then adjusted to 9.5-10, and the liberated HCN is selectively permeated across a tubular silicone rubber membrane into an NaOH absorber. A limit of detection (LOD) of 35 ppbv HCN is attainable with a preconcentration time of 10 min (throughput rate of 5 samples h -1 ) and spectrophotometric determination of cyanide by the Kο#79nlg reaction with sodium isonicotinate and 3-methyl-1-phenyl-2-pyrazolin-5-one

Indirect spectrophotometric determination of cyanide

A spectrophotometric method for cyanide based on its inhibition of the colour formation reaction between nickel(II) and 3-(4′,5′-dimethyl-2′-thiazolylazo)-2,6-dihydroxybenzoic acid has been developed, and allows the determination of down to 0.1 μg of cyanide. Most of the interferences can be avoided by displacement of the hydrogen cyanide using an arsine generator.

Removal of interferences in the spectrophotometric determination of cyanide by dialysis using flow injection analysis

Flow injection analysis (FIA) has been combined with a dialysis unit in order to study the effect of interferences in the determination of free cyanide in waste water. Two kinds of interferences, metals and inorganic anions, were studied. In all the cases, solutions of constant cyanide concentration containing interferences were introduced in the FIA system and free cyanide was determined after hydrogen cyanide passes the dialysis membrane.

The effect of barbituric acid concentration in the spectrophotometric determination of cyanide and thiocyanate by the pyridine-barbituric acid method

The Konig reaction forms the basis of many analytical methods including those for the determination of chlorine, nicotinic acid, thiocyanate and cyanide. The colorimetric methods have, however, been plagued with various problems such as the use of hazardous, often carcinogenic compounds, and the instability of the final color formed as well as of the color reagent itself.

Spectrophotometric determination of cyanide by unsegmented flow methods

Photometric methods for cyanide determination by normal and reversed FIA techniques and by completely continuous monitoring are proposed. The sampling rates for the first two techniques are 20 and 28/hr, respectively, the r.s.d. being less than 0.8% in both cases. A simulation of cyanide control in industrial waste waters shows the usefulness of the continuous monitoring method.

Indirect spectrophotometric determination of cyanide by means of the colour reaction of silver with cadion 2B in presence of triton X-100

Silver gives a colour reaction with cadion 2B in the presence of the non-ionic surfactant Triton X-100, and the suppression of the colour by competitive complexation of the silver can be used for the spectrophotometric determination of cyanide. Cyanide in waste water can be separated by distillation from other ions that also interfere, and then determined.

Spectrophotometric Determination of Cyanide with Isonicotinic Acid and Barbituric Acid

Abstract A spectrophotometric method for the determination of cyanide in water with an isonicotinic acid-barbituric acid reagent having no offensive odor of pyridine is described. Cyanide reacts with chloramine-T, and then the reagent is added to form a soluble violet-blue product, which is measured at 600 nm. Maximum absorbance is achieved in 15 min at 25°C, and remains constant for about 30 min. This method is applicable to water samples containing 0-0.5 μg CN- ml−1. The reagent is stable for at least 4 weeks, if stored at about 10°C. The method is compared with a similar method using sodium isonicotinate and pyrazolone. Application of these methods to determination of cyanide in several plating wastewaters gave good results showing fair agreement with those obtained by the conventional pyridine-pyrazolone method.

Determination of cyanide by an indirect spectrophotometric method using 5-Br-PADAP

Complexation of Ni 2+ with cyanide inhibits its colour reaction with 5-Br-PADAP and this reaction is used in the spectrophotometric determination of cyanide at the ug level. Cyanide in industrial waste waters is determined after an initial transfer as hydrogen cyanide from the sample into sodium hydroxide solution with a stream of air.

Spectrophotometric determination of cyanide after its separation from sulfide by distillation

Spectrophotometric determination of cyanide after its separation from sulfide by distillation

Study of colour-developing factors in spectrophotometric determination of cyanide by the pyridine-barbituric acid method

The decomposition of cyanide-pyridine-barbituric acid in the wavelength around λmax=583 nm gives rise to formation of a new color species around λmax=490nm. Both reactions are first-order reactions with the same K value of 0.066 hr−1, but with opposite sign. The pH value, the nature and concentration of the buffer solution influence absorption to a considerable extent. A method for estimation of cyanide is suggested.

Spectrophotometric determination of cyanide with sodium isonicotinate and sodium barbiturate

Spectrophotometric determination of cyanide with sodium isonicotinate and sodium barbiturate

Spectrophotometric determination of cyanide by use of aqueous potassium iodide and mercury(II) iodide

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Spectrophotometric determination of cyanide with γ-picoline and barbituric acid

A spectrophotometric method for the determination of cyanide in water with a γ-picoline—barbituric acid reagent is described. Cyanide reacts with chloramine-T, and then the reagent is added to form a soluble violet-blue product, which is measured at 605 nm. Maximum absorbance is achieved within 5 min at 25 ± 1°C, and remains constant for about 30 min. This method is applicable to water samples containing 0–0.5 μg CN ml -1. The reagent is stable for at least 3 weeks, if stored at about 10°C. The procedure can also be employed for the determination of thiocyanate.

Spectrophotometric Determination of Cyanide in Biological Materials

Abstract The analytical methods currently used for the determination of cyanide in biological materials are the aeration method with the Prussian blue (ferricyanide) reaction [1] and some microdiffusion methods [2,3]. The methods are dependent on color reactions, the procedures are either time-consuming or cumbersome, and the results are of questionable accuracy. A method using the ultraviolet light absorption characteristics of a cyanonickelate complex was developed by Scoggins [4] for the accurate identification and quantitation of cyanide in aqueous solution. This method was found to be readily adaptable for the determination of cyanide in biofluids and tissues. The resulting cyanide-nickel complex which formed rapidly was found to be stable and could be quantitated readily. This paper presents a method to detect cyanide in biological materials by a spectrophotometric procedure.

Spectrophotometric determination of cyanide, sulfide, and sulfite with mercuric chloranilate

Spectrophotometric determination of cyanide, sulfide, and sulfite with mercuric chloranilate