Cyanide Salts Research Articles

Ionic liquids functionalized chitosan: An effective, rapid and green adsorbent for gold recovery

Thiosulfate has been considered as a more environmentally-friendly alternative to cyanide salts for the extraction of gold from gold ores and the development of affordable, green and efficient adsorbents for the isolation of gold-thiosulfate complex (Au(S2O3)23−) from the leaching solution remains a significant challenge. To address this issue, chitosan, a natural macromolecule, was selected as a carrier and chemically modified with ionic liquids. The ionic liquids modified chitosan showed greater adsorption capacity towards Au(S2O3)23− compared with pristine chitosan. The adsorption of Au(S2O3)23− on ionic liquid modified chitosan followed Freundlich isotherm and pseudo-second order kinetic models, involving an anion-exchange mechanism with liquid film diffusion as the rate-limiting step. The chitosan modified with butylimidazolium-based ionic liquid had an adsorption capacity of 5.0 mg g−1 for gold (10 mg L−1 of gold, pH 6, 2 g L−1 of adsorbent dosage), outperforming other reported adsorbents. The ionic liquid modified chitosan showed a high adsorption efficiency of up to 96.7 % for Au(S2O3)23− in an actual thiosulfate leaching solution with a desorption efficiency of 98.4 %, suggesting that the ionic liquid modified chitosan has the potential to be a eco-friendly, biocompatible and effective adsorbent for the recovery of Au(S2O3)23−.

Cobalt‐Mediated [3+1] Fragmentation of White Phosphorus: Access to Acylcyanophosphanides

AbstractDespite the accessibility of numerous transition metal polyphosphido complexes through transition‐metal‐mediated activation of white phosphorus, the targeted functionalization of Pn ligands to obtain functional monophosphorus species remains challenging. In this study, we introduce a new [3+1] fragmentation procedure for cyclo‐P4 ligands, leading to the discovery of acylcyanophosphanides and ‐phosphines. Treatment of the complex [K(18c‐6)][(Ar*BIAN)Co(η4‐P4)] ([K(18c‐6)]3, 18c‐6=[18]crown‐6, Ar*=2,6‐dibenzhydryl‐4‐isopropylphenyl, BIAN=1,2‐bis(arylimino)acenaphthene diimine) with acyl chlorides results in the formation of acylated tetraphosphido complexes [(Ar*BIAN)Co(η4‐P4C(O)R)] (R=tBu, Cy, 1‐Ad, Ph; 4 a–d). Subsequent reactions of 4 a–d with cyanide salts yield acylated cyanophosphanides [RC(O)PCN]− (9 a–d−) and the cyclo‐P3 cobaltate anion [(Ar*BIAN)Co(η3‐P3)(CN)]− (8−). Further reactions of 4 a–d with trimethylsilyl cyanide (Me3SiCN) and isocyanides provide insight into a plausible mechanism of this [3+1] fragmentation reaction, as these reagents partially displace the P4C(O)R ligand from the cobalt center. Several potential intermediates of the [3+1] fragmentation were characterized. Additionally, the introduction of a second acyl substituent was achieved by treating [K(18c‐6)]9b with CyC(O)Cl, resulting in the first bis(acyl)monocyanophosphine (CyC(O))2PCN (10).

Cobalt-Mediated [3+1] Fragmentation of White Phosphorus: Access to Acylcyanophosphanides.

Despite the accessibility of numerous transition metal polyphosphido complexes through transition-metal-mediated activation of white phosphorus, the targeted functionalization of Pn ligands to obtain functional monophosphorus species remains challenging. In this study, we introduce a new [3+1] fragmentation procedure for cyclo-P4 ligands, leading to the discovery of acylcyanophosphanides and -phosphines. Treatment of the complex [K(18c-6)][(Ar*BIAN)Co(η4 -P4 )] ([K(18c-6)]3, 18c-6=[18]crown-6, Ar*=2,6-dibenzhydryl-4-isopropylphenyl, BIAN=1,2-bis(arylimino)acenaphthene diimine) with acyl chlorides results in the formation of acylated tetraphosphido complexes [(Ar*BIAN)Co(η4 -P4 C(O)R)] (R=tBu, Cy, 1-Ad, Ph; 4 a-d). Subsequent reactions of 4 a-d with cyanide salts yield acylated cyanophosphanides [RC(O)PCN]- (9 a-d- ) and the cyclo-P3 cobaltate anion [(Ar*BIAN)Co(η3 -P3 )(CN)]- (8- ). Further reactions of 4 a-d with trimethylsilyl cyanide (Me3 SiCN) and isocyanides provide insight into a plausible mechanism of this [3+1] fragmentation reaction, as these reagents partially displace the P4 C(O)R ligand from the cobalt center. Several potential intermediates of the [3+1] fragmentation were characterized. Additionally, the introduction of a second acyl substituent was achieved by treating [K(18c-6)]9b with CyC(O)Cl, resulting in the first bis(acyl)monocyanophosphine (CyC(O))2 PCN (10).

Local chemical compounds: synthesis and characterization with antibiotic application

In this work, the main idea was to introduce toxic cyanide compounds, convert them through a chemical reaction into non-toxic compounds, and apply them as growing media in farms to grow mushrooms. Pathogen resistance to traditional antibiotics is becoming a public health issue, necessitating the search for new, effective remedies. α-amino-nitrile ligands are a paramount medium in chemical reactions. The reaction of aromatic aldehydes substituted with various groups and secondary amines (diphenylamine) in the presence of potassium cyanide salt has produced novel organic compounds. Biological contamination went down when three different concentrations (0.015, 0.02, and 0.03) g/L were added to potato dextrose agar (PDA) medium. This didn't hurt the prepared farm and cut the time it took to sterilize from 30 minutes to 10 minutes. IR, 1H-NMR, and melting points characterized the structures of synthesized ligands.

A new 90-day drinking water study of sodium cyanide in rats to further evaluate National Toxicology Program findings and inform risk assessment.

The National Toxicology Program (NTP, 1993) reported male reproductive effects in a sodium cyanide (NaCN) drinking water study. The critical effect, decreased cauda epididymis weights, was used by U.S. Environmental Protection Agency for their hazard characterization and risk assessment of hydrogen cyanide and cyanide salts. To further investigate potential male reproductive effects, we conducted a new 90-day drinking water study. Our study expanded evaluations of testes and thyroid. Male F344 rats received NaCN in drinking water at 0, 0 (water restricted; paired to top dose), 3, 10, 30, 100, and 300 ppm for 13 weeks, followed by 10-weeks recovery. Plasma thiocyanate increased dose-dependently but returned to baseline during recovery. NaCN caused neither effects on survival, body weight, food consumption, hematology, serum chemistry, urinalysis, thyroid hormones, testes or epididymides weights, sperm motility/viability, sperm morphology, or sperm production; nor clinical, ophthalmic, or histopathologic findings. Increased organ weights in thyroid/parathyroid and liver occurred at 300-ppm but were recoverable. No changes occurred in male reproductive organs. Absent adverse effects, the NOAEL was 300 ppm (21.66 mg/kg/day; highest dose tested). Based on organ weight increases at 300 ppm, the NOEL was 100 ppm (7.46 mg/kg/day).

Triorganylphosphoranides: Realization of an Unusual Structural Motif Utilizing Electron Withdrawing Pentafluoroethyl Groups.

Phosphoranides comprising three phosphorus carbon bonds are scarcely represented in the literature. We now utilized tris(pentafluoroethyl)phosphane, P(C2 F5 )3 , and cyanobis(pentafluoroethyl)phosphane, P(C2 F5 )2 (CN), featuring electron withdrawing pentafluoroethyl groups, to synthesize such compounds. Metal fluorides MF (M=Ag, Cs) add to P(C2 F5 )3 yielding respective M[P(C2 F5 )3 F] salts. Those M[P(C2 F5 )3 F] subsequently suffer a loss of C2 F4 , furnishing M[P(C2 F5 )2 F2 ]. The cesium salt decomposes instantaneously when warmed to rt, whereas the silver salt decomposes slowly over several days at rt. Treatment of Ag[P(C2 F5 )3 F] with 2,2'-bipyridine facilitated the isolation and structural characterization of [Ag(bipy){P(C2 F5 )3 F}]. With P(C2 F5 )2 (CN), AgF reacts under substitution of the cyano group yielding P(C2 F5 )2 F, rather than phosphoranide formation. However, [K(18-crown-6)]F adds to P(C2 F5 )2 (CN) furnishing [K(18-crown-6)][P(C2 F5 )2 (CN)F]. Its structural characterization was successful, despite its tendency to undergo an exchange of substituents, yielding [K(18-crown-6)][P(C2 F5 )2 F2 ] and presumably [K(18-crown-6)][P(C2 F5 )2 (CN)2 ]. The latter forms an equilibrium with [K(18-crown-6)]CN and P(C2 F5 )2 (CN) which lies well on side of the phosphane and cyanide salt.

Morphology, properties and stress-strain state of carburized gear made of steel 12KhN3A after high-frequency currents quenching

The results of the study of the effect of cementation with subsequent induction quenching by high-frequency currents on the physical properties of a gear made of 12HN3A steel are presented, the influence of technological factors (temperature and time) on the cementation layer is studied. The study was carried out using a well-known pasty carbonatesoot carburetor and in a pasty carburetor with composition optimization through the synthesis of a di-ammonium salt of 2-monoethanolamine and citric acid, in terms of carbon saturation activity of steel not inferior to melts of cyanide salts. The structure and chemical composition of 12HN3A steel before and after cementation were studied. In the course of the work, the following mode of chemical-thermal treatment of 12HN3A steel was used: cementation due to exposure to highfrequency currents temperature T = 960 °C, medium — air; induction hardening due to exposure to high-frequency currents temperature T = 860 °C, medium — aqueous solution, tempering low temperature T = 190 °C, medium — aqueous a solution that provides an increase in the margin coefficient for fatigue strength to 86.1 MPa and yield strength to 820 MPa while maintaining a sufficient level of plastic properties. The stress-strain state of a gear wheel made of 12HN3A steel is estimated before and after cementation of its working surfaces with subsequent induction hardening by high-frequency currents.

Impact of Selected Processing Methods of High-Level Cyanide in Cassava on Optic Neuropathy in Wistar Albino Rats—An Experimental Study

Background: Cassava tuber crop is a staple food rich in carbohydrates and utilized in various forms by millions of Nigerians. The storage root of the cassava contains linamarin, a cyanogenic glycoside that is easily hydrolyzed to release cyanide salt compounds which is toxic to the nervous system especially the optic nerve, sometimes leading to optic neuropathy and visual impairment. Aim: The aim of this study is to find out the impact of selected processing methods of high-level cyanide in cassava on optic neuropathy in Wistar albino rats. Methodology: Twenty-four Wistar albino rats were fed with different concentration and duration of predetermined high-cyanide content cassava root cultivar which was processed using different processing methods adopted by various communities in Rivers State, Nigeria (for human consumption). A control group of 3 Wistar albino rats was fed with normal “Growth Mesh” meals. The pre and post weights of the animals and the fundoscopic optic nerve status of the rats were evaluated after 30 and 60 days. SPSS Version 25 was employed for descriptive and inferential statistical analyses. A p-value of ≤0.05 was considered statistically significant. Results: The Cassava species available in Rivers State have high cyanide content (2336.79 mg CN-/kg dry weight of cassava). There was statistically significant reduction in the cyanide content (p = 0.000) depending on the various common processing methods (into garri for human consumption): 24 hours, 48 hours, fermentation; with and without red palm oil additive. The individual weights as well as the mean weight of the 24 rats in the experimental group increased gradually from the first week to the 9th week with a slight weight reduction on the third and fourth weeks which was not statistically significant (p = 0.092). However, there was a steady increase in the weights of the animals in the control group throughout the 9 weeks. Varying degrees of optic neuropathy occurred, worse with the rats that had 24-hour fermented cassava twice daily for 60 days. The intra and inter group differences in the optic disc changes was statistically significant (p = 0.000). Conclusion: Longer duration of processing cassava roots into garri for human consumption reduces its cyanide content and minimizes the adverse impact on the optic nerve.

Organic Acid to Nitrile: A Chemoenzymatic Three-Step Route.

Various widely applied compounds contain cyano-groups, and this functional group serves as a chemical handle for a whole range of different reactions. We report a cyanide free chemoenzymatic cascade for nitrile synthesis. The reaction pathway starts with a reduction of carboxylic acid to aldehyde by carboxylate reductase enzymes (CARs) applied as living cell biocatalysts. The second - chemical - step includes in situ oxime formation with hydroxylamine. The final direct step from oxime to nitrile is catalyzed by aldoxime dehydratases (Oxds). With compatible combinations of a CAR and an Oxd, applied in one-pot two-step reactions, several aliphatic and aryl-aliphatic target nitriles were obtained in more than 80% conversion. Phenylacetonitrile, for example, was prepared in 78% isolated yield. This chemoenzymatic route does not require cyanide salts, toxic metals, or undesired oxidants in contrast to entirely chemical procedures.

Thiol functionalized activated carbon for gold thiosulfate recovery, an analysis of the interactions between gold and sulfur functions

Cyanide salts are currently used as leaching agents in gold extraction processes despite their toxicity. Thiosulfate is a greener choice, but its employment is constrained by the difficulty at recovering gold thiosulfate from the leachate using activated carbon, which in contrast, works well for gold-cyanide adsorption. Aiming to solve this problem, activated carbon has been covalently functionalized with thiol groups (-SH) through a peptide bond formation with cysteamine, as thiol-carrier molecule. The functionalized carbon accomplishes up to 100% Au recovery (with 2 and 25 ppm Au solution) in 8 h contact and its performance seems independent on the solution's pH. In-depth solid characterization techniques (XPS, TOF-SIMS, FTIR, PXRD, TEM, N₂ physisorption, elemental analysis) have been used to unravel the interactions between Au thiosulfate and thiol functions and two different gold adsorption mechanisms have been demonstrated: under acid conditions, the formation of Au1+- S chains has been proven. Under basic conditions, Au⁰ species have been detected in addition to Au1+- S chains. Elution of the gold loaded samples has been accomplished at a 71% level using Na₂S₂O₃ and NH₄OH as eluents.

Nickel-Catalyzed Cyanation of (Hetero)aryl Bromides Using DABAL-Me3 as a Soluble Reductant.

A nickel-catalyzed cyanation of (hetero)aryl halides using air-stable bis(trimethylaluminum)-1,4-diazabicyclo[2.2.2]octane (DABAL-Me3) as a soluble reductant has been developed. The reaction uses readily available and inexpensive Ni(dppf)Cl2 as a precatalyst, a substoichiometric amount of Zn(CN)2, and DABAL-Me3 as an alternative to commonly prescribed insoluble reductants. We found the addition of catalytic tetrabutylammonium bromide (TBABr) to be beneficial, due to facilitating dissolution of low levels of the cyanide salt (confirmed via a control study). Similarly, slow addition of a tetrabutylammonium cyanide (TBACN) solution is effective and results in a completely homogeneous reaction mixture.

Main group cyanides: from hydrogen cyanide to cyanido-complexes

Abstract Homoleptic cyanide compounds exist of almost all main group elements. While the alkali metals and alkaline earth metals form cyanide salts, the cyanides of the lighter main group elements occur mainly as covalent compounds. This review gives an overview of the status quo of main group element cyanides and cyanido complexes. Information about syntheses are included as well as applications, special substance properties, bond lengths, spectroscopic characteristics and computations. Cyanide chemistry is presented mainly from the field of inorganic chemistry, but aspects of chemical biology and astrophysics are also discussed in relation to cyano compounds.

Comparative multi-species analysis of potassium cyanide toxicity

Potassium cyanide (KCN), a highly water soluble and bioaccumulative cyanide salt, is examined to determine the toxic effects by using two green algae (Dunaliella viridis, Nannochloropsis oculata) and genetically different two sea urchin (Paracentrotus lividus, Arbacia lixula) species. To determine the toxic effects on the early developmental stages of sea urchin embryos, 72-hour embryotoxicity studies were conducted. Potassium cyanide toxicity at cellular level was also investigated and 6-hour embryos of both sea urchin species were used to determine genotoxic effects of KCN. Since plutei naturally feed on microalgae, two species of plankton were used to reveal phytotoxic effects of KCN. KCN was found to be embryo- geno- and phytotoxic. EC50's for P. lividus and A. lixula were found 7.96 and 6.52 μM. IC50's for N. oculata for 48 h and 72 h were found 23.66 and 80.45 μM. IC50's for D. viridis for 48 h and 72 h were found 14.31 and 23.36 μM.

Copper-Catalyzed Sulfonylation of Cyclobutanone Oxime Esters with Sulfonyl Hydrazides

AbstractA copper-catalyzed radical cross-coupling of cyclobutanone oxime esters with sulfonyl hydrazides has been developed. The copper-based catalytic system proved crucial for cleavage of the C−C bond of cyclobutanone oximes and for selective C–S bond-formation involving persistent sulfonyl-metal radical intermediates. This protocol is distinguished by the low-cost catalytic system, which does not require ligand, base, or toxic cyanide salt, and by the use of readily accessible starting materials, as well as broad substrate scope, providing an efficient approach to various diversely substituted cyano-containing sulfones.

Making headway with the mysteries of life’s origins

In 1863, Charles Darwin opined in a letter to a friend that contemplating the origin of life was “mere rubbish thinking” and that “one might as well think of [the] origin of matter.” Many researchers today would agree with Darwin. And yet, whereas cosmologists know how particles, elements, and many molecules formed after the big bang, biologists still struggle to explain how inorganic molecules turned into the stuff of life. Natural lakes with relatively high concentrations of phosphorous compounds, such as Mono Lake in California, may have been commonplace in the prebiotic Earth, providing the phosphorus-rich environments for biology and life to take hold. Image credit: Shutterstock/Radoslaw Lecyk. While seeking signs of fossilized microbial life in Mars’ Jezero crater, once home to a river delta, NASA’s Perseverance rover could uncover evidence of ferrocyanide derivatives, which would favor a hypothesis about how life started—one in which hydrogen cyanide reacts with the abundant iron dissolved in the waters of a lake, forming ferrocyanide, and causing cyanide salts to accumulate and react with flowing water. Image credit: NASA/JPL-Caltech. That’s partly because no one researcher or laboratory can tackle all aspects of the problem. But recent experiments and simulations—studying planetary habitability, the conditions needed to produce biomolecules in the ratios and concentrations for self-sustaining metabolism, and the ways in which the precursors to DNA and RNA might have assembled and replicated—are beginning to answer some fundamental questions about the origin of life. Multiple labs are tackling these interdisciplinary challenges with myriad approaches. At least one team believes they might be on track to learn how life got a start on our planet. “For years, people working on the origin of life had many ideas but nothing that fell into place as a single working pathway,” says astronomer Dimitar Sasselov of Harvard University in Cambridge, …

Speciation and determination of iron in aqueous solution and river water by high-resolution electrospray ionization mass spectrometry

Characterization and determination of Fe2+ co-existing with Fe3+ using a simple method of electrospray ionization mass spectrometry (ESI-MS) is employed. We attempted to characterize Fe2+ species in aqueous solution in combination with various inorganic salts of iron, such as chloride, sulfate, and cyanide salts, using two kinds of detection systems (a quadrupole mass spectrometer and a high-resolution magnetic mass spectrometer), to establish the stability of the complexes formed. The study further extended to the determination of Fe2+ concentration, and we expect that ESI-MS will be a new method to determine Fe2+. Among the inorganic salts studied, 1,10-Phenanthroline forms stable tetrahedral complexes with Fe2+ in the gas phase of ESI-MS which is observed in a high-m/z region and are well separated. The method is extended for determining Fe2+ concentration in natural river water samples by measuring the peak intensity of [Fe(phen)2]2+ (m/z 208) and obtaining a calibration curve (R2 = 0.9992) of the peak intensity determined by HR-ESI-MS. The Fe2+ concentrations in Tama River samples were obtained by the standard addition method (Fe2+ 0.23 μmol/L, R2 = 0.9998), and total concentration of iron in Tama River sample was 0.59 μmol/L (ICP-MS), thus about 40% of iron is present as Fe2+.

Bronze Electroplating: Stability, Nucleation and Growth Study of a New Green Formulation

Bronze electroplating is a widely used process in the electronics and costume jewelry industrial sectors as an anti-corrosion coating and barrier layer against intermetallic diffusion. The study of this alloy is also essential for the realization of copper-zinc-tin sulfide (CZTS) compounds, a quaternary semiconductor with a growing interest for the realization of thin film photovoltaic devices. The galvanic baths currently on the market are alkaline with a high amount of sodium or potassium cyanide to complex the metal ions. Cyanide salts are extremely dangerous for their toxicity, blocking cellular respiration. For this reason, cyanides are considered a danger both for the environment as well as for the workers with whom it comes in contact. In this study, a new eco-friendly, acidic and cyanide-free formulation was developed for the deposition of the Cu-Sn alloy.To achieve this goal, methanesulfonic acid (MSA) was chosen as electrolyte, which is biodegradable as part of the natural sulfur cycle. Various recipes have been evaluated to obtain a solution that was stable over time and that did not lead to the precipitation or oxidation of its components. Copper sulphate, copper methanesulfonate and tin methanesulfonate solutions were used as precursors of the metals [1]. As stabilizing additives nitrilotriacetic acid (NTA) and 2-picolinic acid (2PA), complex agents for copper, and hydroquinone (HYD), antioxidant agent for tin, were evaluated. The composition of the films, obtained both by potentiostatic and galvanostatic deposition, were analyzed by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS) and, to investigate the structural phases of the deposits, XRD measurements were carried out. Finally, nucleation and growth as a function of the concentration of thiourea (TU) and potassium and sodium tartrate (PST), regulating additives for the deposition of copper and tin, respectively, were studied by chronoamperometric methods, in order to achieve progressive growth and therefore a lucid deposit. The present study funded by the PRIN Project (“Progetti di Ricerca di Rilevante Interesse Nazionale”), “Novel Multilayered and Micro-Machined Electrode Nano-Architectures for Electrocatalytic Applications (Fuel Cells and Electrolyzers)”, grant number 2017YH9MRK.

Modified congener analysis: Quantification of cyanide in whole blood, other body fluids, and diverse beverages

The congener analysis is routinely used for the determination of volatile compounds in body fluids and beverages for forensic investigations. Although intoxications with cyanide via smoke inhalation or ingestion of cyanide salts are frequently encountered in forensic medicine, the inclusion of hydrogen cyanide in this analysis was never studied in detail. In this work, a very simple, fast, and sensitive quantification method with headspace gas chromatography and flame ionization detection for the analysis of cyanide in whole blood-was developed and validated. In contrast to the standard sample preparation of the congener analysis, an acidification step with tartaric acid was added. A limit of detection of 50 ng/ml, good linearity (coefficient of correlation > 0.9997), high accuracy (101.5%-106.4%), and precision (relative standard deviation 1.8%-3.7%) were achieved. Authentic blood samples of 10 forensic cases were investigated with the new method. Furthermore, the method was used for the quantification of cyanide in other body fluids (serum and urine) and diverse beverages. Interferences were investigated, and the addition of aldehydes produced a clear concentration-dependent decrease of the cyanide signal. Besides, the method offers an economical use of limited sample material by the simultaneous determination of cyanide, ethanol, and congener alcohols.

Louis Armand Victor Amedée Cailliot

Amedee Cailliot (1805-1884), a French physician and pharmacist who isolated for the first time several new acids (among them terephthalic) from turpentine, prepared a series of double salts of mercuric cyanide and potassium (and sodium) bromide and several derivatives of pimaric acid.

Gas chromatography-mass spectrometric identification of cyanide using a nucleophilic substitution based derivatization with S-phenyl benzenethiosulfonate.

A novel, simple and efficient analytical method for GC-MS based identification of cyanide has been developed using a single step nucleophilic substitution based derivatization of cyanide in aqueous medium. The nucleophilic substitution reaction of cyanide with S-phenyl benzenethiosulfonate results in the formation of phenyl thiocyanate as a cyanide derivative and it was found that the relative response of the resultant cyanide derivative was much higher than that of the cyanide derivatives resulting from disulfide based derivatizing agents. The sample preparation protocol for the identification of cyanide in aqueous samples was also optimized with the new derivatizing agent. Derivatization followed by liquid-liquid extraction was employed for the preparation of aqueous samples containing cyanide salts. The resultant samples were subjected to GC-MS analysis for the identification of the cyanide derivative. Under optimized conditions, the detection and quantification limits for cyanide aqueous samples were found to be 0.075 μg mL-1 and 0.25 μg mL-1 respectively. The calibration curve had a linear relationship with y = 0.086x - 0.076 and r2 = 0.997 for the working range of 0.25 μg mL-1 to 50 μg mL-1. The intraday RSDs were between 2.24 and 8.17%, and the interday RSDs were between 2.22 and 12.85%. The method can also be successfully employed for the identification of hydrogen cyanide in aqueous medium. The applicability of the present method was demonstrated by analysing a real sample from apple seed extraction.