Determination Of Cyanide In Water Research Articles

Determination of Cyanide in Water and Food Samples Using an Efficient Naphthalene-Based Ratiometric Fluorescent Probe.

Monitoring cyanide levels in water and food samples is crucial. Herein, we rationally developed a simple and efficient fluorescent probe for cyanide determination. The probe displayed selective ratiometric fluorescent response to cyanide. In addition, after treatment with cyanide, the fluorescence ratios (I509/I466) exhibited a good linearity with cyanide concentration in the range of 0–60 μM, and the detection limit was determined to be 0.23 μM (S/N = 3). Significantly, the practical application demonstrated that the probe was able to quantitatively detect cyanide concentration in natural water samples. Monitoring of endogenous cyanide in cherry nut by the probe was also successfully conducted. Notably, upon fabrication of test strips, the probe could be conveniently utilized for field measurement of cyanide in bitter almond without relying on sophistical instruments. Furthermore, the cyanide in potato tissues was determined for the first time by means of fluorescence imaging.

Flow Injection On-Line Distillation Method for Determination of Cyanide in Water

Purpose The flow injection distillation (zinc acetate solution) was changed to be 5% phosphoric acid in the method of determination of cyanide. Application Cyanide in groundwater was measured by FIA6000 + automatic flow injection analyzer directly. Results In the 2.0-100.0μg/L range, the linear correlation coefficient was greater than 0.9, the recovery was 86.1% -100.8%, relative standard deviation 1.3% -3.8%. Conclusion This method not only reduces the white crystals [Zn (OH)2] on the pump tube blockage, making the operation more simple and efficient, but also for the detection of a large number of groundwater samples.

A Selective Spectrofluorometric Determination of Micromolar Level of Cyanide in Water Using Naphthoquinone Imidazole Boronic-Based Sensors and a Surfactant Cationic CTAB Micellar System

We developed a new spectrofluorometric method for qualitative and quantitative determination of cyanide in water using the incorporation of naphthoquinone imidazole boronic-based sensors (m-NQB and p-NQB) and a cationic surfactant, certyltrimethyl ammonium bromide (CTAB). This micellar system exhibited great selectivity for cyanide detection with an assistance of the cationic surface of micelle. The interaction of boronic acid of the sensor toward cyanide in CTAB micellar media gave a quantitative measure of cyanide concentration in the micromolar level. Under the optimal condition, fluorescence intensity at 460 nm of m-NQB and p-NQB provided two sets of linear ranges, 0.5-15 μM and 20-40 μM and the limit of cyanide detection of 1.4 μM. Hence, both sensors in CTAB aqueous micellar system offered a considerably promising cyanide detection with 1000-fold enhancement of the detection limit compared to those studied in DMSO: H(2)O. The proposed sensors could also be used to determine cyanide in water with good analytical characteristics.

Indirect determination of free cyanide in water and industrial waste water by flow injection-atomic absorption spectrometry

A simple and rapid flow injection system is proposed for indirect determination of cyanide by flame atomic absorption spectrometry. It consists of a microcolumn of immobilized salen (N,N′-bis(salicylidene)ethylenediamine) on sodium dodecyl sulfate (SDS)-coated alumina saturated with silver ion and a carrier of dilute solution of sodium hydroxide (10−5 mol L−1). The micro-column was located between the injection valve and nebulizer of atomic absorption spectrometry. Injection of 250 µL of aqueous cyanide standard or sample solution at pH range of 9–11 cause elution of silver as silver cyanide complexes, which was then measured by flame atomic absorption spectrometry. The absorbance was proportional to the concentration of cyanide in the sample. The graph of absorbance (as peak height) vs. cyanide concentration was linear over the concentration range of 0.1–10 mg L−1 of cyanide, and the detection limit was 0.06 mg L−1. The relative standard deviation at 1 and 3 mg L−1 of cyanide concentration were 4.1 and 4.7%, respectively. The method was successfully applied to determination of cyanide in water and industrial waste waters, and the accuracy was examined through independent analysis by accepted method of pyridine-barbituric acid.

Concept of contemporary methods for monitoring and determination of cyanide in water

The quality of life depends on water quality. Good water quality and the rational use of water are an absolute need of the new millennium. Although it is an ecological and health priority to prohibit the contamination of water and water protection, it is a responsibility for environmental engineers and chemists to develop and apply effective methods for monitoring and controlling of water quality, and at that way prevent ecological and technological catastrophe on time. In this paper modern methods and process for monitoring, control and detection of cyanide in water and wastewater are presented. Recent developments in instrumental techniques and treatment for determination of this toxic substance in water are described, particularly the methods according to green analytical aspects.

The determination of cyanide in water and biological tissues by methemoglobin

The authors developed a simple and sensitive method for the determination of cyanide using spectrophotometry to measure changes caused by cyanide in the absorption spectra of methemoglobin. Met-hemes in the hemoglobin molecules react with cyanide rapidly to form a cyanomethemoglobin complex, even at low concentrations of cyanide, in a stoichiometric manner. After adding cyanide, the absorption spectra of methemoglobin changed with a typical decrease in absorbance at 630 nm, and an increase in absorbance at 540 nm. These changes were closely correlated with the concentrations of cyanide ion. From the results, it was shown that 0.2 μg/ml of cyanide ion in water and 0.4 μg/ml in biological tissues can be detected by this method. The method may be useful for the convenient and sensitive detection of cyanide in waste water and biological tissues and fluids.

Determination of Free Cyanide in Water by Released Flourescence of a Dissociated Ternary Complex

Abstract A flourometric procedure for the analysis of free cyanide is described. The method is based on the dissociation of a ternary complex of silver-1, 10-phenanthroline-tetrabromofluorescein by cyanide to produce a fluorescent product. The fluorescence intensity is found to be directly proportional to the cyanide concentration. The method can reliably detect 0.02 μg/mL cyanide.

Separation and automatic spectrophotometric determination of low concentrations of cyanide in water

Semi-automatic methods are described for the routine determination of cyanide in water. Membrane diffusion and isothermal distillation are examined for the separation/concentration of cyanide; the isothermal distillation procedure is optimized for routine use. An air-segmented flow analyzer is used to quantify cyanide. Two classical spectrophotometric methods are adapted and compared. The method based on reaction with picric acid is applicable at cyanide concentrations exceeding 1 mg l −1. A modified Aldridge method is far better for lower concentrations. Combination of isothermal distillation with the automatic version of the Aldridge method is suitable for the determination of cyanide in waters in the concentration range 0.01–10 mg l −1. Interference by sulphide and sulphite and their removal are described.

A Discussion of the Method for the Determination of Free Cyanide in Water and Wastewater by Microdiffusion

ASTM Committee D-19 on Water has recently published a method for the determination of free cyanide in water and wastewater by microdiffusion. This method (ASTM Method for the Determination of Free Cyanide in Water and Wastewater by Microdiffusion [ASTM D 4282-83]) is based on adjusting a sample in a microdiffusion cell to pH 6.0. All cyanides present that can form hydrogen cyanide (HCN) are defined as free cyanide by this method. The HCN is allowed to diffuse for 4 h into the center chamber of the microdiffusion cell, which contains sodium hydroxide. The cyanide ion thus formed is chlorinated and then reacted with pyridine-barbituric acid. A colorimetric measurement is made to determine the cyanide level. The round robin data obtained show percent biases of −1.9, −5.0, and −4.2% at concentrations of 32, 80, and 144 μg/L of CN−, respectively, in Reagent Type II water. Data are shown from the original investigation that established the method parameters. Additional pertinent work is documented.

Indirect determination of cyanide in water by atomic-absorption spectrophotometry

An indirect method for determination of trace cyanide in water by atomic-absorption spectrophotometry is described. Cyanide forms a stable complex anion with Pd in alkaline solution. This complex anion can form an ion-association complex with tetra-alkylammonium ions which can be extracted into n-butyl alcohol with an efficiency higher than 90%. The extract can be analysed directly for palladium (and hence indirectly for cyanide) by flame atomic-absorption spectrophotometry. The detection limit for cyanide by this method is 0.1 μg ml in the n-butyl alcohol extract. Beer's law is obeyed for 0.13–9 μg of CN − per ml of n-butyl alcohol. Several foreign ions do not interfere.

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.

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.