• Journal of The Korean Society of Clinical Toxicology
• /
• v.4 no.1
• /
• pp.55-57
• /
• 2006

Cyanides and Hydrogen cyanide are used in production of chemicals, electroplating, photographic development, making plastics, fumigating ships, and some mining processes. We experienced of Hydrogen cyanide inhalation injury. A 45-year-old man worked at electroplating. As soon as he mixed sodium cyanide with acid, cyanide produced hydrogen cyanide, occasionally he inhaled Hydrogen cyanide and he lost his consciousness. He was moved to near hospital and took emergency treatment and then was transferred to our hospital. On arrival he had severe dyspnea, metabolic acidosis, and tachycardia. After he was treated with supportive method he recovered his consciousness in 20 hours at emergency room.

• Journal of Korean Society on Water Environment
• /
• v.25 no.6
• /
• pp.979-983
• /
• 2009

The mean pH of wastewater discharged from the plating process is 2, so a less amount of alkali is required to raise pH 2 to 5. In addition, if sodium sulfite is used to raise pH 5 to 9 in the secondary treatment, caustic soda or slaked lime is not necessary or only a small amount is necessary because sodium sulfite is alkali. Thus, it is considered desirable to use only $FeSO_4{\cdot}7H_2O$ in the primary treatment. At that time, the free cyanide removal rate was highest as around 99.3%, and among heavy metals, Ni showed the highest removal rate as around 92%, but zinc and chrome showed a low removal rate. In addition, the optimal amount of $FeSO_4{\cdot}7H_2O$ was 0.3g/L, at which the cyanide removal rate was highest. Besides, the free cyanide removal rate was highest when pH value was 5. Of cyanide removed in the primary treatment, the largest part was removed through the precipitation of ferric ferrocyanide: $[Fe_4(Fe(CN)_6]_3$, and the rest was precipitated and removed through the production of $Cu_2[Fe(CN)_6]$, $Ni_2[Fe(CN)_6]$, CuCN, etc. Furthermore, it appeared more effective in removing residual cyanide in wastewater to mix $Na_2SO_3$ and $Na_2S_2O_5$ at an optimal ratio and put the mixture than to put them separately, and the optimal weight ratio of $Na_2SO_3$ to $Na_2S_2O_5$ was 1:2, at which the oxidative decomposition of residual cyanide was the most active. However, further research is required on the simultaneous removal of heavy metals such as chrome and zinc.

• Journal of the Korean Chemical Society
• /
• v.17 no.6
• /
• pp.411-415
• /
• 1973

The reaction between cyanide ion and triphenyl methane dyes is subject to marked catalysis by cationic micelles of cetyltrimethyl ammonium bromide(CTABr) and retarded by anionic micelles of sodium lauryl sulfate(NaLS). Added salts, anions inhibit the catalysis by CTABr, and cations, especially $Zn^{++},\;Cd^{++}$ decrease the retardation of the reaction rates in the presence of NaLS. The kinetic effects of the ionic micelles are much larger in water than in ethanol-water, methanol-water, propanol-water and acetone-water, but strange solvent effects, acceleration the reaction rates, was found in the reaction with malachite green in water-methanol system.

• Toxicological Research
• /
• v.28 no.3
• /
• pp.195-199
• /
• 2012

The records of 255 cyanide poisoning deaths obtained from National Forensic Service (NFS) headquarters, located in Seoul of Korea, from 2005 to 2010 were retrospectively reviewed. The mean age was $41.88{\pm}13.09$ and range was 6~80 years (unknown in seven cases). The number of deaths of males and females were 200 and 53, respectively (unknown in two cases). The largest number of cases occurred in people aged 40-49 years (81 cases, 31.8%), followed by the age groups 30~39 years (51 cases, 20%), 50~59 years (44 cases, 17.2%) and 20~29 years (43 cases, 16.9%). The total number of deaths among other age groups (below 10, 10~19, 60~69, 70~79, over 80 years and unknown) were 36, representing only 14.1%. Of all cyanide poisoning deaths, 97.3% were due to suicide, and 14.5% of the total number who died received medical treatment. The most frequent site for ingestion was the person's own residence (120 cases, 47.1%) and the route of administration was mainly oral (252, 98.8%). From the total of 255 cyanide poisoning cases, white powders were submitted for analysis in 92 cases. Potassium cyanide and sodium cyanide occupied 51 and 41 cases, respectively. This study showed that poisoning deaths due to cyanide are one of the continuously reported public health problems in Korea. Enforcement of regulations and safety education to prevent cyanide poisoning should be carried out by the government.

• Corrosion Science and Technology
• /
• v.6 no.6
• /
• pp.304-307
• /
• 2007

As to the reflection electrode of LCD (liquid crystal displays), silver-copper-gold alloy (hereafter, it is called as ACA (Ag98%, Cu1%, Au1%)) is an effective material of which weathering resistance can be improved more compared with pure silver. However, there is a problem that gold remains on the substrate as residues when ACA is etched in cerium ammonium nitrate solution or phosphoric acid. Gold can not be etched in these etchants as readily as the other two alloying elements. Gold residue has actually been removed physically by brushing etc. This procedure causes damage to the display elements. Another etchant of iodine/potassium iodide generally known as one of the gold etchants can not give precise etch pattern because of remarkable difference in etching rates among silver, copper and gold. The purpose of this research is to obtain a practical etchant for ACA alloy. The results are as follows. The cyanogen complex salt of gold generates when cyanide is used as the etchant, in which gold dissolves considerably. Oxygen reduction is important as the cathodic reaction in the dissolution of gold. A new etchant of sodium cyanide / potassium ferricyanide whose cathodic reduction is stronger than oxygen, can give precise etch patterns in ACA alloy swiftly at room temperature.

• Journal of Surface Science and Engineering
• /
• v.19 no.3
• /
• pp.92-108
• /
• 1986

An electroplating on the lead frame fabricated from domestic copper plate was studied experimentally. In this study, nickel was plated on the thin copper lead frame and silver layer was coated on the nickel film in the cyanide electrolyte. The effect of process variables such as current density, plating time, coating thickness and flow rate of electrolytic solution on the properties of coating was investigated. Some samples on each step were fabricated during electroplating. The results obtained from polarization measurement, observation of SEM photograph, adhesion test of coating and microhardness test are as follows. On silver plating, polarization resistance of potentiostatic cathodic polarization curve is reduced as the flow rate of Ag electrolytic solution increases. And above resistance is also reduced when the minor chemicals of sodium cyanide and sodium carbonate are added in potassium silver cyanide bath. The reduced polarization resistance makes silver deposition on the cathode easy. An increase in the current density and the coating thickness causes the particle size of deposit to coarsen, and consequently the Knoop microhardness of the coating decreases. On selective plating an increase in the flow rate of plating solution lead to do high speed plating with high current density. In this case, the surface morphology of deposit is of fine microstructure with high Knoop hardness. An increasing trend of the adhesion of coating was shown with increasing the current density and flow rate of electrolytic solution.

• The Korean Journal of Physiology
• /
• v.30 no.1
• /
• pp.105-116
• /
• 1996

Rendering the brain ischemic would evoke the cerebral ischemic reflex which is characterized by an arterial pressor response, apnea and bradycardia. Since the rostral ventrolateral medulla (RVLM) is known to play a key role in the maintenance of normal cardiopulmonary activity, during the cerebral ischemic reflex some cardiac related cells should be excited and respiration related cells inhibited. In this context, the responses of RVLM neurons to systemie and focal hypoxia were analyzed in the present study. Twenty-five adult cats of either sex were anesthetized with ${\alpha}-chloralose$ and the single neuronal activities were identified from RVLM area. For the induction of focal hypoxia in the recording site, sodium cyanide was applied iontophoretically and for systemic hypoxia the animal was ventilated with nitrogen gas for a twenty-second period. Cellular activities were analyzed in terms of their discharge pattern and responses to the hypoxia by using post-stimulus time and single-pass time histograms. Of eighteen cardiac related cells recorded from the RVLM area, twelve cells were excited by iontophoresed sodium cyanide and of twenty-five respiration related cells, fourteen cells were excited by iontophoresed sodium cyanide. Remaining cells were either inhibited or unaffected. Eight of fifteen cells tested with iontophoresed sodium lactate were excited and remaining seven cells were inhibited. Systemic hypoxia induced by nitrogen gas inhalation elevated the arterial blood pressure, but excited, inhibited or unaffected the single neuronal activities. Some cells showed initial excitation followed by inhibition during the systemic hypoxia. Bilateral vagotomy resulted in a decrease of arterial pressor response to the systemic hypoxia, and a slight decrease in the rhythmicity related to cardiac and/or respiratory rhythms. The single neuronal responses to either systemic or focal hypoxia were not affected qualitatively by vagotomy. From the above results, it was concluded that the majority of the cardiac- and respiration- related neurons in the rostral ventrolateral medulla be excited by hypoxia, not through the mediation of peripheral chemoreceptors, and along with the remaining inhibited cells, all these cells be involved in the mediation of cerebral ischemic reflex.

• The Journal of Korean Medicine
• /
• v.26 no.3 s.63
• /
• pp.135-145
• /
• 2005

Objectives : This study investigated effect of Evodiae fructus water extract (EVOR) on apoptotic cell death induced by NaCN in SK-N-SH neuroblastoma cell lines. NaCN stimulates glutamate release which can activate glutamate receptors to initiate excitotoxic processes. This study examines the role of EVOR in mediating NaCN-induced cytotoxicity. Methods & Results : Cytotoxicity was assessed by measuring lactate dehydrogenase (LDH) in the culture media. NaCN(0.1mM) produced cytotoxicity following 12hrs of incubation. NaCN-induced cytotoxicity was partially blocked by EVOR. The treatment of EVOR in simultaneous exposure of cultures to NaCN provided complete protection against cytotoxicity. NaCN-induced cytotoxicity was found to inhibit DNA fragmentation, repaired by cell cycle and simultaneous exposure to NaCN, regenerated with neurite outgrowh by EVOR. These results indicate thaf damage by NaCN in neumnal cell cultures was repaired by EVOR, whereas NaCN-induced cytotoxicity is blocked Primarily by activation of anti-apoptosis. Conclusions : These results suggest that EVOR may be beneficial for the treatment of dementia and other degenerative problems of the central nervous system.

• Journal of Korean Society on Water Environment
• /
• v.26 no.4
• /
• pp.687-690
• /
• 2010

The objective of this study is to investigate the effect of aldehyde compounds and ploysulfide as accelerating agents on removal of heavy metals and CN in plating wastewater. As a results of the experiments, the removal efficiency of cyanide using the formaldehyde type of aldehydes was the highest at pH 9. Next types were sodium formaldehyde bisulfite addut> paraldehyde> paraformaldehyde. Also, optimum pH and dosage for treating the residual heavy metals by using polysulfide were pH 9 and 30 mg/L, respectively. The removal efficiencies of cyanide, chromium, zinc and copper were above 96.7% at optimum condition.

• Resources Recycling
• /
• v.26 no.4
• /
• pp.88-94
• /
• 2017

The recovery of gold in cyclone type electrolytic cell was conducted from solution for stripping gold of PCB by cyanide. The electrolytic recovery behaviors of gold was investigated by reaction time and addition of electrolytic sodium hypochlorite (NaOCl) and gold plating additive (KG-120). Because the electrolysis generated NaOCl reacted with the cyanide in the leachate by alkaline chlorination, more than 99% of the cyanide was removed at a $NaOCl(g)/CN^-(g)$ ratio of 1.0. When NaOCl was added during the recovery of the gold from cyanide leachate in the cyclone electrolytic cell, the recovery of gold was 98% at the ratio of $NaOCl(g)/CN^-(g)$ from 0.5 to 2.5 in 480 minutes and decreased rapidly over the ratio of 3.0. Gold was recovered more than 99% by adding 1.5 and 4.5%(v/v) of KG-120 with NaOCl in 480 minutes. In particular, when the concentration of KG-120 was 3.5 and 4.5%(v/v), more than 96% of gold was recovered within 240 minutes and the initial recovery rate was relatively faster. The optimum concentration of KG-120 is 3.5%(v/v) considering the economic feasibility and efficiency.