Showing papers on "Cyanide published in 1987"

Microbial cyanide production in the rhizosphere in relation to potato yield reduction and Pseudomonas SPP-mediated plant growth-stimulation

Abstract: Inhibition of root cell energy metabolism is suggested to be responsible for potato yield reductions in short potato-rotation soils. Hydrogen cyanide is the microbial metabolile possibly involved in inhibition of energy metabolism. This is supported by the following observations: (1) approximately 50% of potato rhizosphere pseudomonads was shown to produce cyanide in vitro; (2) 5 μM HCN inhibited cytochrome oxidase respiration by at least 40% in intact potato roots in vitro; (3) cyanide production in vitro by Pseudomonas sp. isolate WCS361 depended on the Fe3+ concentration of the medium. Growth promoting fluorescent Pseudomonas spp isolates WCS374 and WCS358 did not produce cyanide in vitro. A hypothesis, that potato plant growth is depressed in short potato rotation soils by the microbial production of cyanide in the rhizosphere is discussed. In such soils, bacteria producing specific siderophores increase growth by competing with cyanide-producing organisms for Fe3+.

Hydroxycobalamin/sodium thiosulfate as a cyanide antidote

Abstract: Severe, acute cyanide poisoning is uncommon and can be very difficult to diagnose if a history of exposure is unavailable. Victims of smoke inhalation may have significant cyanide poisoning as well as carbon monoxide toxicity. The Lilly Cyanide Antidote Kit ® currently available in America unfortunately has its own inherent toxicity. An efficacious antidote lacking toxicity is desirable, especially in cases where the diagnosis of cyanide poisoning cannot be made with certainty. Hydroxycobalamin/sodium thiosulfate has been used in France since 1970. Both components have been shown to be safe and efficacious in animal studies. Case reports of human cyanide poisoning treated with hydroxycobalamin/sodium thiosulfate have been published only in French. Animal and human data on the use of this antidotal combination are reviewed. Hydroxycobalamin/sodium thiosulfate is an efficacious cyanide antidote with little inherent toxicity.

Toxic smoke inhalation: cyanide poisoning in fire victims.

Abstract: The most common cause of death in fires is the inhalation of noxious gases rather than thermal injury. Hydrogen cyanide gas, the most toxic product of combustion, seldom is recognized as a significant hazard in smoke inhalation. During the first four months of 1986, toxic amounts of cyanide were found in four of the six fatalities from house fires in Akron, Ohio. These cases illustrate the increasing frequency of cyanide poisoning in household fires. Sources of cyanide toxicity include the increased use of synthetic polymers in building materials and furnishings. Prompt recognition of and therapy for cyanide intoxication may reduce the morbidity and number of delayed deaths in fire victims. The key point in the diagnosis of cyanide poisoning is a high index of suspicion. The clinical presentation of cyanide intoxication, its diagnosis, and subsequent treatment are discussed. Finally, a prehospital protocol for treating smoke-inhalation victims who may have been exposed to cyanide gas is suggested.

Cadmium accumulation by a Citrobacter sp. immobilized on gel and solid supports: Applicability to the treatment of liquid wastes containing heavy metal cations.

Abstract: Polyacrylamide gel-immobilized cells of a Citrobacter sp. removed cadmium from flows supplemented with glycerol 2-phosphate, the metal uptake mechanism being mediated by the activity of a cell-bound phosphatase that precipitates liberated inorganic phosphate with heavy metals at the cell surface. The constraints of elevated flow rate and temperature were investigated and the results discussed in terms of the kinetics of immobilized enzymes. Loss in activity with respect to cadmium accumulation but not inorganic phosphate liberation was observed at acid pH and was attributed to the pH-dependent solubility of cadmium photsphate. Similarly high concentrations of chloride ions, and traces of cyanide inhibited cadmium uptake and this was attributed to the ability of these anions to complex heavy metals, especially the ability of CN(-) to form complex anions with Cd(2+). The data are discussed in terms of the known chemistry of chloride and cyanide-cadmium complexes and the relevance of these factors in the treatment of metal-containing liquid wastes is discussed. The cells immobilized in polyacrylamide provided a convenient small-scale laboratory model system. It was found that the Citrobacter sp. could be immobilized on glass supports with no chemical treatment or modification necessary. Such cells were also effective in metal accumulation and a prototype system more applicable to the treatment of metal-containing streams on a larger scale is described.

The growth of a cyanide-utilising strain of Pseudomonas fluorescens in liquid culture on nickel cyanide as a source of nitrogen

Abstract: Pseudomonas fluorescens strain NCIMB11764 is able to utilise cyanide as a source of nitrogen for growth. When KCN(≡ HCN) is the source of nitrogen it has to be supplied as the limiting nutrient in fed-batch cultures [1]. In this study it has been shown that metal-complexed cyanide, as nickel cyanide (Ni(CN)2−4), can be used as the source of nitrogen when it is added directly to the growth medium in batch cultures. Ni(CN)2−4 could also be used as the source of nitrogen in nitrogen-limited continuous cultures. In both batch and continuous cultures, growth on Ni(CN)2−4 was associated with induction of cyanide oxygenase activity. An assay for cyanide has been developed utilising its binding to nickel.

The induction of cyanide-resistant respiration in Hansenula anomala.

Abstract: Cyanide-resistant respiration was induced in the yeast, Hansenula anomala in the presence of cyanide or antimycin A, which blocks the electron transport after ubiquinone The de novo protein synthesis in cytosol and oxygen were deduced to be involved in this induction process The period required for the induction varied during the growth stage, suggesting that involvement of additional physiological factor(s) in this induction process The organism could multiply in the presence of antimycin A by developing cyanide-resistant respiration despite a decreased growth rate

Cyanide concentrations in blood after cigarette smoking, as determined by a sensitive fluorimetric method.

Abstract: Using the sensitive fluorimetric method described here, we evaluated the determination of blood cyanide as a method for monitoring exposure to tobacco smoke. The mean concentration of cyanide in blood from eight nonsmokers was 0.098 (SD 0.036) mumol/L. The concentration of cyanide in blood of smokers who had refrained from smoking for at least 2 h before sampling peaked immediately after the subjects smoked a cigarette, then rapidly declined, with a half-life of about 4 min. Its rapid disappearance from blood makes cyanide an unsuitable marker of exposure to tobacco smoke. Because the ability of patients with hepatic dysfunction to detoxify cyanide has been presumed to be impaired, we monitored the concentrations of cyanide in the blood of four patients with severe hepatic insufficiency who smoked a cigarette. The rate of elimination of cyanide from blood after smoking was only slightly less in these patients than in the controls, and the difference was not statistically significant.

Cyanide in blood by gas chromatography with NP detector and acetonitrile as internal standard. Application on air accident fire victims

Abstract: An improved gas chromatographic method for HCN in blood with acetonitrile as an internal standard has been developed. The necessity to test for cyanide on samples from air accident fire victims is discussed in view of the fact that carbon monoxide measurements usually do not correlate with cyanide findings. Nine cases (out of 67), with blood CO saturation of less than 20% and cyanide concentration over 2 mg/L, are described.

Indirect determination of cyanide compounds by ion chromatography with conductivity measurement

Abstract: Ion chromatography (IC) is a suitable analytical technique for the determination of anions. The cyanide is not detected by the conductivity detector of the ion chromatograph due to its low dissolution constant (pK = 9.2). This paper describes an IC procedure for the determination of free cyanide and metal cyanide complexes that uses a conductivity detector. It is based on the oxidation of cyanide ion by sodium hypochlorite to cyanate ion (pK = 3.66). Therefore, cyanide ion can now be measured indirectly by the conductivity detector. In this procedure, optimum operating conditions were examined. In addition, the interferences from anions and reducing agents were investigated. The method was applied to the determination of metal cyanide complexes. The coefficients of variation (%) for CN/sup -/ (1.05 mg/L), Zn(CN)/sub 4//sup 2 -/ (CN/sup -/, 0.80 mg/L), and Ni(CN)/sub 4//sup 2 -/ (CN/sup -/, 0.96 mg/L) were 1.1%, 1.5%, and 0.5%, respectively. The proposed method proved to be useful for the determination of cyanide compounds in natural water and waste water.

Selective solvation extraction of gold from alkaline cyanide solution by alkyl phosphorus esters.

Abstract: Research efforts have shown that solvation extraction of gold from alkaline cyanide solution is possible by alkyl phosphorus esters. Both tributyl phosphate (TBP) and dibutyl butyl phosphonate (DBBP) appear to be effective extractants for gold and exhibit high loading capacities exceeding 30 gpl. Selective solvation extraction of gold from alkaline cyanide solution can be achieved with selectivity factors relative to other cyanoanions as high as 1000 under certain circumstances. Variables influencing the selectivity such as ionic strength, temperature, and extractant structure, are discussed in terms of the extraction chemistry, which seems to involve the solvation of a M dot, dot, dot Au(CN)2 ion pair.

Electrolytic oxidation of cuprocyanide electroplating waste waters under different pH conditions

Abstract: The main purpose of this work was to investigate the electrolytic oxidation of cuprocyanide solution with various total cyanide to copper molar ratios ranging from 2.8 to 20 and under different pH conditions. In strong alkaline solution (pH≥12), cuprocyanide ions Cu(CN) /(−1)− , wheren=2, 3 or 4, are directly electroxidized, and copper oxide precipitates on the anode. Cyanate ions, as well as nitrogen gas, were detected as the products and 0.30–0.43 g mol of total cyanide was destroyed per Faraday. For less alkaline solutions (pH<12), cuprocyanide ions first dissociated to free cyanide ions and then electroxidized. At a pH of 10.5–11.7, cyanate ion and brown azulmin polymer were produced in the anolyte. In the neutral solution (pH=7.0–8.6), carbonate and ammonium ions and azulmin were formed and 0.52–0.56 g mol of total cyanide was destroyed per Faraday. In weak acidic solution (pH=5.2–6.8), oxalate and ammonium ions and white oxamide were produced and 1.01–1.18 g mol of total cyanide were destroyed per Faraday.

Process for wastewater treatment

Abstract: Free cyanide-containing wastewater is treated to destroy the free cyanide content thereof by the step of treating said water with sulfur in the form of polysulfide in an integrated process wherein thiocyanate is also eliminated to produce a non-hazardous wastewater effluent and treating the wastewater in a second step with cultures of bacteria of the genus Thiobacillus in combination with nitrifying bacteria which oxidize ammonia to nitrite to nitrate. The first step is preferably carried out in the presence of a cationic surfactant, preferably a quaternary cationic surfactant, as a catalyst.

The contribution of intracellular acidosis to the decline of developed pressure in ferret hearts exposed to cyanide.

Abstract: 1. The concentrations of phosphorus-containing metabolites were measured using 31P nuclear magnetic resonance (n.m.r.) in Langendorff-perfused ferret hearts. The hearts were stimulated at a constant rate and developed pressure was measured. 2. The inhibition of oxidative phosphorylation with cyanide (2 mM) decreased developed pressure. This was accompanied by an intracellular acidosis, a fall in the concentration of phosphocreatine ([PCr]) and a rise in that of inorganic phosphate ([Pi]). 3. The effects of cyanide on developed pressure were compared with those of simply decreasing the intracellular pH (pHi) (by elevating CO2) to match the change produced by cyanide. The change of pHi alone resulted in about 33% of the decrease of force produced by cyanide. 4. The relationship between developed pressure and pHi was investigated by altering CO2. It could be described by an equation of the form:log developed pressure = a + b pHi where a and b were independent of pHi. The addition of cyanide decreased a but had no significant effect on b. In other words a given change of pHi had the same fractional effect on pressure in the absence as in the presence of cyanide. 5. In another series of experiments, after cyanide had been added, pHi was returned to control levels by decreasing CO2. This increased developed pressure. Nevertheless the pressure was still considerably less than in control. Furthermore, if the acidosis was abolished by decreasing CO2 at the same time as cyanide was added developed pressure still decreased. 6. We conclude that most of the decrease of developed pressure produced by cyanide is not produced by intracellular acidosis and may result from increased [Pi].

Pentacyanoruthenate(II)-pentaammineruthenium(II/III) binuclear complexes bridged by cyanogen, cyanide, and 4,4'-bipyridine

Abstract: Preparation de complexes dinucleaires [(CN) 5 RuLRu(NH 3 ) 5 ] n− avec L=bipyridine-4,4', dicyanogene et CN − . Donnees polarographiques et voltammetriques

Integrated process for biological treatment of sulfate-containing industrial effluents

Abstract: During this investigation, upflow anaerobic, packed bed or upflow anaerobic, suspended sludge reactors were used. The biological process, where, following the addition of an organic carbon source such as molasses, converts sulfate to gaseous hydrogen sulfide. Hydrogen sulfide can be converted to elemental sulfur and heavy metals, which are normally present in mining effluents, are precipitated as insoluble metal sulfides and completely removed. Remaining hydrogen sulfide traces are aerobically reconverted to sulfate, while calcium carbonate crystallization and degradation of organic carbon residuals are achieved simultaneously. Cyanide in the effluent biodegrades. Any remaining weakly biodegradable components can be removed in a secondary anaerobic stage. Thus, this process produces reusable water and elemental sulfur.

Nitrite/thiosulfate treated acute cyanide poisoning: estimated kinetics after antidote.

Abstract: A 34 year old, 73 kg man ingested a 1 gram potassium cyanide pellet in a suicide attempt. Within one hour, coma, apnea, metabolic acidosis, and seizures developed. Sodium nitrite and sodium thiosulfate were administered. Dramatic improvement in the clinical condition occurred by the completion of antidote infusion. Methemoglobin level was 2% immediately after nitrite administration. Serial whole blood cyanide levels were obtained, documenting a highest measured level of 15.68 mcg/mL. Estimations of toxicokinetic parameters including terminal half-life (t 1/2) (19 hours), clearance (163 mL/minute), and volume of distribution (Vd) (0.41 L/kg) were calculated. The nitrite/thiosulfate combination was clinically efficacious in this case and resulted in complete recovery.

A study of ligand binding to spleen myeloperoxidase.

Abstract: The ligand binding properties of spleen myeloperoxidase, a peroxidase formerly called "the spleen green hemeprotein", were studied as functions of temperature and pH, using chloride and cyanide as exogenous ligands. Ligand binding is influenced by a proton dissociable group with a pKa of 4. The protonated, uncharged form of cyanide binds to the unprotonated form of the enzyme, while chloride ion binds to the enzyme when this group is protonated. In both cyanide and chloride binding, the pH-dependent change in the apparent ligand affinity is due to a change in the apparent association rate with pH. The proton dissociable group on the enzyme involved in ligand binding has a delta H value of about 8 kcal . mol-1. The present results suggest that this ionizable group is the imidazole group of a histidine residue located near the ligand binding site.