Cyanide Ions In Water Research Articles

Miniaturized dual-wavelength β-correction spectrophotometric probe for sensitive detection of cyanide in water via formation of cyano dithizone adduct

Cyanide toxicity in water significantly threatens public health and the environment. To address this, a miniaturized simple, low-cost, selective and sensitive direct dual wave β-correction spectrophotometric probe has been established for cyanide detection in water. The dual-wavelength β-correction spectrophotometry enhances the selectivity and sensitivity of the probe in the presence of interfering species. The assay relies a highly selective nucleophilic addition of cyanide ions to dithizone (H2Dz) as chromogenic reagent in aqueous media of pH 6.8–7.2, forming a red-colored cyano H2Dz adduct. The electronic spectrum of the formed adduct displays a sharp absorption peak at λmax = 480 nm, enabling precise colorimetric detection. The molar absorptivity and Sandell’s sensitivity index for the cyano H2Dz adduct with and without β-correction spectrophotometry were 5.62 × 103, and 1.79 × 103 L mol−1 cm−1, and 0.002 and 0.0033 µg cm−2, respectively. Beer’s law and Ringbom’s plots are valid in the range 0.01–5.0 and 0.06–2.0 µg mL−1 CN– concentration, respectively. The limits of detection (LOD) and quantification (LOQ) improved from 1.03 × 10−1 and 3.13 × 10−1 μg/mL using ordinary spectrophotometry to 2.8 × 10−2 and 8.7 × 10−2 μgmL−1 employing β-correction spectrophotometry. The probe offers rapid response, good anti-interference ability, reproducibility, and cost-effectiveness. The probe was successfully applied for detection of trace levels of cyanide ions in water with good repeatability. It has been also validated in water samples with good recoveries (99.2 ± 5.02 %). The experimental Student t test (texp = 1.2–1.5) was lower than the critical (texp = 2.78) at 95 % probability (n = 5). The stoichiometry and mechanism of formation of the cyano adduct were assigned and addressed.

Water-soluble coumarin based sequential colorimetric and fluorescence on-off chemosensor for copper(II) and cyanide ions in water

A new colorimetric and fluorescent water-soluble chemosensor Lg for the sequential detection of copper(II) and cyanide ions has been synthesized and characterized. This probe comprises two coumarin sugar units linked by an ethylenediamine spacer. The chemosensor Lg exhibits selectively a quenched fluorescence in the presence of copper(II) cations, as well as a redshift of the absorbance at 380 nm. However, in the presence of other cations, Lg exhibits a strong fluorescence at 492 nm. Furthermore, the formed complex Lg/Cu2+ is selectively fluorescent in the presence of cyanide anions, and its absorbance data show a clear blue shift due to the release of the starting probe Lg and the formation of the highly stable complex Cu(CN)2. The detection limit was calculated to be 0.34 and 0.13 μM for copper(II) and cyanide ions, respectively.

Colorimetric and turn-on fluorescent chemosensor with large stokes shift for sensitively probing cyanide anion in real samples and living systems

Cyanide anion is a ubiquitous chemical substance in the ecosystem, however, human daily life is severely threatened by its toxicity at any time. In this paper, a novel colorimetric and turn-on chemosensor 4-(4-(2,2-difluoro-6-methyl-2H-1,3,2-dioxaborinin-4-yl)buta-1,3-dien-1-yl)-N,N-dimethylaniline (NBF) for detecting cyanide anion was synthesized based on the 4-(dimethylamino)cinnamaldehyde and β-diketone difluoroboron complex. This fluorescent probe exhibited excellent spectroscopy properties such as large stokes shift, long emission wavelength, and good sensitivity. The detection limit of NBF towards cyanide ion was determined as low as 2.23 μM. Additionally, the detection mechanism towards cyanide ion was confirmed to be the nucleophilic addition interaction by high resolution mass spectrum (HRMS), 1H Nuclear Magnetic Resonance (NMR) titration, and quantum chemistry theory calculation. In addition, the probe NBF had been successfully utilized in detecting cyanide ions in water and food samples as well as imaging in the biological system, which broadened its practical application prospects.

Cover Feature: Selective and Sensitive Fluorescence Turn‐On Detection of Cyanide Ions in Water by Post Metallization of a MOF (ChemPlusChem 1/2022)

The Cover Feature shows a potential sensory material (CuCl2@MOF-867), which has been developed by post metallization (CuCl2) of a water stable luminescent metal-organic framework, namely MOF-867, constructed with bipyridyl functionality as organic linker. The sensory probe demonstrates highly selective and sensitive aqueous phase “turn-on” detection towards toxic cyanide (CN-) ions even in the presence of other co-existing anions with a very low limit of detection (0.19 μM), which is considerably lower than the WHO permissible limit in water. More information can be found in the Full Paper by Sujit K. Ghosh, and co-workers.

Selective and Sensitive Fluorescence Turn-On Detection of Cyanide Ions in Water by Post Metallization of a MOF.

Owing to detrimental impact of cyanide ion (CN- ) towards the entire living system as well as its availability in drinking water, it has become very important developing potential sensory materials for the selective and sensitive recognition of CN- ions in water. In the domain of sensory materials, luminescent metal-organic frameworks (LMOFs) have been considered as a promising candidate owing to their unique host-guest interaction, where MOFs can serve as an ideal scaffold for encapsulating relevant guest molecules rendering specific functionality. In this study, a post-synthetically modified MOF (viz., CuCl2 @MOF-867) was applied to recognize cyanide (CN- ) ions in water via "turn-on" response. The bipyridyl functionalities in MOF-867 were used to perform post-synthetic metalation to infiltrate CuCl2 inside porous architecture of the MOF. Moreover, a CuCl2 @MOF-867 based probe demonstrated highly selective and sensitive aqueous phase recognition of CN- ions even in the presence of other interfering anions such as Br- , NO3- , I- , SO42- , OAc- , SCN- , NO2- , etc. The selective binding of CN- ions to the copper-metal center has led to the generation of stable Cu(CN)2 species. This phenomenon has further resulted in a fluorescence turn-on response. The aqueous phase cyanide detection by the rationally modified MOF system exhibited very low limit of detection (0.19 μM), which meets the standardized limit stated by World Health Organization (WHO) that is 1.9 μM.

A novel sugar pyrazolin-5-one based optical chemosensor for sequential detection of copper (II) and cyanide ions in real samples. Experimental and theoretical studies

A novel colorimetric glyco-conjugated chemosensor for sequential detection of the copper (II) and cyanide ions in water has been developed starting from lactose pyrazolin-5-one derivative. The presented chemosensor revealed a high sensitivity and selectivity toward copper (II) and cyanide ions in water under competitive conditions in real samples. The calculated limit of detection for copper (II) and cyanide ions was 2.7 × 10−7 and 1.07 × 10−6 mol.L−1 respectively. Furthermore, the unglyco-conjugated chemosensor derivative was successfully utilized in the preparation of the kit test by its adsorption on the silica matrix surface for the detection of copper(II) and cyanide ions in aqueous water samples.

Pillar[5]arene-functionalized paper as a fluorescent sensor for cyanide ions in water

In this work, we developed a strategy to prepare pillararene-functionalized paper, which absorbed 10-methyacridinium iodide as a fluorescent indicator for cyanide ions, allowing their naked-eye detection from 10−7 to 10−3 M.

A reversible fluorescent chemosensor for the rapid sensing of CN− in water: utilization of the intramolecular charge transfer blocking

A reversible fluorescent sensor combines naphthyridine groups as signaling subunits and the presence of the active hydrogen of the primary amine confers the recognition capacity toward cyanide ions in water.

Cationic polythiophene for specific detection of cyanide ions in water using fluorometric technique

A new fluorometric cyanide sensor using cationic polythiophene exhibits high sensitivity, selectivity with a low detection limit (4.4 ppb) in water.

A catalytic chemodosimetric approach for detection of nanomolar cyanide ions in water, blood serum and live cell imaging.

Naphthimidazolium based monocationic chemodosimeters CD-1 and CD-2 undergo cyanide mediated catalytic transformation in the presence of cyanide ions (0.01% to 1% of CD-1/CD-2 concentrations) with a turnover number from 70 to 360. These chemodosimeters can detect as low as 0.5 nM and 1 nM cyanide ions under nearly physiological conditions (HEPES buffer-DMSO (5%), pH 7.4). The structures of CD-1 and its cyanide induced hydrolyzed product 4 have been confirmed by single crystal X-ray crystallography. CD-1 can also be used for the determination of 2 nM cyanide in the presence of blood serum. CD-1 and CD-2 also find applications in live cell imaging of 10 nM cyanide ions in rat brain C6 glioma cells. To the best of our knowledge, this is the first report where high sensitivity towards cyanide ions has been achieved through catalytic hydrolysis of the fluorescent chemodosimeter.

An Efficient Probe for Rapid Detection of Cyanide in Water at Parts per Billion Levels and Naked‐Eye Detection of Endogenous Cyanide

A new molecular probe based on an oxidized bis-indolyl skeleton has been developed for rapid and sensitive visual detection of cyanide ions in water and also for the detection of endogenously bound cyanide. The probe allows the "naked-eye" detection of cyanide ions in water with a visual color change from red to yellow (Δλmax =80 nm) with the immediate addition of the probe. It shows high selectivity towards the cyanide ion without any interference from other anions. The detection of cyanide by the probe is ratiometric, thus making the detection quantitative. A Michael-type addition reaction of the probe with the cyanide ion takes place during this chemodosimetric process. In water, the detection limit was found to be at the parts per million level, which improved drastically when a neutral micellar medium was employed, and it showed a parts-per-billion-level detection, which is even 25-fold lower than the permitted limits of cyanide in water. The probe could also efficiently detect the endogenously bound cyanide in cassava (a staple food) with a clear visual color change without requiring any sample pretreatment and/or any special reaction conditions such as pH or temperature. Thus the probe could serve as a practical naked-eye probe for "in-field" experiments without requiring any sophisticated instruments.

Rapid and highly selective dipchecking for cyanide ions in aqueous media

This article reports a simple dipping method for the detection of cyanide ions in water and biological samples, such as blood, using chitosan-gold nanoparticle (CH-Au NP) composite films prepared using CH-Au NP colloids. Here, gold nanoparticles were generated by heating (to ~80 °C) a solution of chitosan and gold chloride, where chitosan plays the dual role of reducing and stabilizing agent. The well-known chemistry of leaching of gold by cyanide is exploited here to detect cyanide ions. The CH-Au films showed the localized surface plasmon resonance (LSPR) absorption, similar to the CH-Au colloidal solution, at 534 nm. Gold nanoparticles (Au NPs) in the films are found to be dissolved quantitatively, causing a proportional decrease in intensity of the LSPR peak. Color change was observable by the naked eye above a concentration of 2 mg L(-1) of CN(-) in solution. We found a good correlation between the reduction in intensity of the absorption peak at 534 nm and concentrations of CN(-) ions as low as 0.06 mg L(-1). Most of the previously reported methods for cyanide detection involve tedious chemistry, demand the use of sophisticated instruments and still are not suitable for on-site cyanide monitoring. Our reported approach is rapid, eco-friendly, low cost, easy to use, and highly selective for cyanide detection in aqueous solution. We feel that this simple, low cost, novel and portable method is suitable particularly for third world countries, where more sophisticated aids are not so common.

A Highly Selective Cyanide Sensor

The selective detection of low concentrations of cyanide ions in water is of high importance. In order to achieve this goal, the authors synthesized the two sulfonium boranes 3 and 6 and tested their application as hosts for cyanide. Compound 3 was synthesized from the tetra­kis(THF) lithium salt of dimesityl-1,8-naphthalenediylborate (1) by reaction with dimethyldisulfide and methylation of the obtained product 2. Compound 6 was obtained by treating ortho-lithiothioanisole (4) with dimesitylboron fluoride and meth­ylation of the product.

Sulfonium Boranes for the Selective Capture of Cyanide Ions in Water

Going fishing! The sulfonium borane [1](+) complexes cyanide in pure water at the maximum allowable concentration of 50 ppb recommended by the European Union. The high cyanide ion affinity displayed by this compound arises from favorable Coulombic effects augmented by a direct bonding interaction between the cyano and sulfonio groups.

Sulfonium Boranes for the Selective Capture of Cyanide Ions in Water

AbstractFischen nach CN−: Das Sulfonioboran [1]+ komplexiert Cyanid in reinem Wasser bei der EU‐weit empfohlenen maximalen Arbeitsplatzkonzentration von 50 ppb. Die hohe Affinität für Cyanidionen ist das Ergebnis günstiger Coulomb‐Effekte im Verbund mit einer direkten bindenden Wechselwirkung zwischen Cyanidionen und Sulfoniogruppen.magnified image

Spectrophotometric determination of cyanide ion in waste water using copper(II) and N,N-diethyl-p-phenylenediamine

Spectrophotometric determination of cyanide ions in water was studied using Cu(II) ions and N,N-diethyl-p-phenylenediamine(DPD). A cyanide ions reacted with Cu(I) ions, producing a stable complex, CuCN (s.p.=3.5×10−20). Then, Cu(II) ions were reduced to Cu(I) ions with DPD owing to a decrease of Cu(I) ions. The concentaration of the coloring oxidant of DPD was proportional to the concentration of cyanide ions between 0.1 and 2.0 mg CN− l−1. The coloring development by this method was attained in one minute. A copper formate was the most suitable copper salt for a reaction in copper chloride, copper sulfate and copper acetate because of its highest sensitivity and lowest blank. The influences of co-existing metal ions [(Cr(III): 40 mg l−1), (Ag(I): 0.3 mg l−1), (Fe(II): 0.4 mg l−1), (Fe(III): 3 mg l−1), (Ni(II): 0.16 mg l−1), (Co(II): 0.01 mg l−1) and (Zn(II): 100 mg l−1)] were less than 10% for 0.4 mg l−1 of cyanide ions. No influences of co-existing metals on the linearity of calibration curve were observed. This method is very simple, and can be used for the pre-detection of cyanide ions in waste water.

Highly selective and sensitive reaction of cyanide with 2,2-dihydroxy-1,3-indanedione.

A novel reaction of cyanide with 2,2-dihydroxy-1,3-indanedione in the presence of sodium carbonate is described. It is highly selective and sensitive, and suitable for the determination of hydrogen cyanide in the environment and free cyanide ions in water, blood, urine, serum, etc. As little as 1.25x10(-7) mol x L(-1) CN(-) (3.25x10(-9) g x mL(-1) cyanide) can be determined by use of this reaction. The color system obeys Beer's law in the range 10 ng x mL(-1) to 1.0 microg x mL(-1) at 510 nm. The molar absorptivity was 8.0x10(4) L x mol(-1) x cm(-1) for a solution of concentration 0.2 microg x mL(-1). All other important analytical properties of the reaction have been studied. It is proposed that the purple color produced under these reaction conditions is that of 2-cyano-1,2,3-trihydroxy-2 H indene.

Organothallium compounds : V. Reactions of bis(pentafluorophenyl)thallium(III) compounds with iodide ions

Bis(pentafluorophenyl)thallium(III) compounds, (C 6F 5) 2TIX (X = Br, Cl, 1 2 SO 4, OAc, etc.), are decomposed by iodide ions in boiling aqueous ethanol, aqueous methanol, or water with the formation of thallous iodide and pentafluorobenzene. Analogous reactions are possible with bromide or cyanide ions. However, reaction with acidified iodide or bromide ions gives the corresponding tetrahalothallate(III) complex. The formation of thallous iodide in reactions without added acid is attributed to intermediate formation of the tetraiodothallate(III) complex and base, which then interact to give thallous iodide. The ready decomposition of MTII 4 (M = Bu 4N or MePh 3As) complexes by base to give thallous iodide has been demonstrated. Under suitable conditions, cleavage of bromobis(pentafluorophenyl)thallium(III) with iodide ions gives the triiodopentafluorophenylthallate(III) complex, which has been isolated as the tetrabutylammonium or the methyltriphenylarsonium salt. The new compounds (C 6F 5) 2 TIX (X = I or CN) have been prepared by metathesis between sulphatodi[bis(pentafluorophenyl)thallium(III) and iodide or cyanide ions in water. They are considered to be dimeric with bridging iodide or cyanide groups.