Explore chapters and articles related to this topic
Basic Chemical Hazards to Human Health and Safety — I
Published in Jack Daugherty, Assessment of Chemical Exposures, 2020
Epoxides are extremely nucleophilic and chemical reactive. Many are carcinogens. Epoxide hydrolases detoxify epoxides. Amines, R–NH2, are oxidized to aldehydes and acids and conjugated to hydrophilic derivatives. Industrial nitro-derivatives, R-NO2, are reduced by hydroxylation. Aromatic hydrocarbons, halogenated aromatic hydrocarbons, and polycyclic hydrocarbons are detoxified by reaction with acetyl mercapturic acid, –SCH2CHCOOH. Inorganic and organic cyanides are neutralized by producing thiocyanate, RCNS. Glycine, –NHCH2COOH, metabolizes aromatic acids, aromatic-aliphatic acids, furane carboxylic acids, thiophene carboxylic acids, and polycyclic carboxylic acids (the Bile acids). Primary, secondary, and tertiary aliphatic and aromatic hydroxyl compounds are metabolized by glucuronate. Hydrazine derivatives are neutralized by glucose hydrazone.
Environmental Health
Published in Lorris G. Cockerham, Barbara S. Shane, Basic Environmental Toxicology, 2019
Camille J. George, William J. George
Cyanide inhibits cytochrome oxidase, an important enzyme in respiration. Treatment with sodium nitrite increases methemoglobin (Stewart, 1974) which has a higher affinity for cyanide than does cytochrome oxidase. Treatment with sodium thiosulfate enhances the excretion of the cyanide as thiocyanate (Chen and Rose, 1952; Stewart, 1974). Both the thiocyanate metabolite and cyanide itself can be measured by gas chromatography.
Chemicals from Non-hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Sulfur reacts with nitrogen to form polymeric sulfur nitrides (SNx) or polythiazyl derivatives. These polymers were found to have the optical and electrical properties of metals. An important sulfur-nitrogen compound is tetrasulfur tetranitride (S4N4) which exists in a cage-like form and, when heated, yields polymeric sulfur nitride (SH)n, which has metallic properties. Thiocyanate derivatives contain the SCN− group and oxidation of thiocyanate gives thiocyanogen, (SCN2, NCS-SCN). Phosphorus sulfides are also commercially important especially those with the cage structures P4S10 and P4S3.
Isoquinolinium-N-sulfonic acid thiocyanate/H2O2 as efficient reagent for thiocyanation of N-bearing (hetero)aromatic compounds
Published in Journal of Sulfur Chemistry, 2021
Sobhan Rezayati, Fatemeh Kalantari, Ali Ramazani, Elham Ezzatzadeh
Moreover, this method is included in a direct method for the formation of C–S bonds, which is a very useful reaction in organic synthesis [9]. Thiocyanate compounds have an essential role in various areas of organosulfur chemistry which can be readily transformed into other functional groups such as thionitrile [10], aryl nitrile [11], thiocarbamate [12], sulfide [13], thiophenols [14], allyl sulfides [15], 5-sulfenyl tetrazoles [16], alkyl trifluoromethyl thioethers [17], disulfides [18], nitriles [19] and S-argio carbamothioate [20] (Scheme 2). Additionally, the products of thiocyanates and thiocyanation have been widely used as drugs, dyes and precursors for agrochemicals, as well as proved useful as intermediates in the synthesis of sulfur-containing heterocycles [21].
Biodegradation of cyanide in cassava wastewater using a novel thermodynamically-stable immobilized rhodanese
Published in Preparative Biochemistry & Biotechnology, 2021
Adedeji Nelson Ademakinwa, Mayowa Oladele Agunbiade, Oladapo Fagbohun
Rhodanese assay was carried out using the methods described by Westley[29] as modified by Atere et al.[30] and Ogudugu et al.[31] The reaction mixture contained 250 mM sodium thiosulfate and potassium cyanide, 50 mM borate buffer pH 9.4 and 0.1 mL enzyme solution (1.98 RU) in a final volume of 1.0 mL. The reaction mixture was incubated for 1 min at 25 °C and then terminated by the addition of 0.5 mL formaldehyde (38% v/v). For the control, the enzyme was added only after formaldehyde was introduced into the reaction mixture. The thiocyanate formed was quantified using methods described by Sorbo[32] in which Sorbo reagent [ferric nitrate + nitric acid] was added to the formaldehyde-containing reaction mixture. The thiocyanate was quantified by measuring absorbance at 460 nm using the molar extinction coefficient value of 4200 M−1 cm−1[33]
Study on release characteristics and removal of polycyclic aromatic hydrocarbons in solid waste coking sulfur paste during heating
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Yongle Zhao, Guoqiang Li, Tao Li, Hongyu Wang, Shuting Zhang, Yongfa Zhang
Wet CSP from the desulfurization section of Yixing Coking Co., Ltd. of Shanxi Province, China, was used as experimental material. The wet CSP was dried in a vacuum drying oven for 8 h at 80°C under vacuum at 0.08 MPa, and ground into powder with a particle size of less than 0.2 mm. In addition to sulfur, dry CSP (D-CSP) contains complex impurities. Water-soluble impurities such as thiocyanate and thiosulfate could be removed by the ammonia extraction method (CN Patent 2016). However, coal tar-like PAHs, which have strong intermolecular dispersion force and poor compatibility with water, were similar to the eight ring structure of sulfur (Khalili-Fard et al. 2012). Therefore, this kind of impurity was easily compatible with the sulfur foam floating on the top of the regeneration tower to form a new interface layer on the surface of fine sulfur (Zhang, Hu, and Liu et al. 2016), so that it was the most difficult to be separated from D-CSP. At the same time, the new interface layer would form an unsaturated force field with high surface energy and a certain amount of charge. Thus, generating an electric field to adsorb polarized water molecules and various ions in the range could come into being an adsorption water layer (Sghaier et al. 2016). Due to the high viscosity, the adsorbed water layer could absorb the coking coal particles in the desulfurization liquid. Figure 1 shows the adhesion bond between impurities and sulfur in D-CSP.