Methylene dichloride toxicity

As a result of its highly polar character, silica gel is particularly useful in the separation of polarizable materials such as the aromatic hydrocarbons and polynuclear aromatics. It is also useful in the separation of weakly polar solute mixtures such as ethers, esters and in some cases, ketones. The mobile phases that are commonly employed with silica gel are the n-paraffins and mixtures of the n-paraffins with methylene dichloride or chloroform. It should be borne in mind that chloroform is opaque to UV light at 254 nm and thus, if a fixed wavelength UV detector is being used, methylene dichloride might be a better choice. Furthermore, chloroform is considered toxic and requires special methods of waste disposal. Silica gel is strongly deactivated with water and thus, to ensure stable retentive characteristics, the solvent used for the mobile phase should either be completely dry or have a controlled amount of water present. The level of water in the solvent that will have significant effect on solute retention is extremely small. The solubility of water in n-heptane is... 

This part is certainly the least developed, to our knowledge. It is important to remember, however, that an animal may ingest a toxic plant and may also survive. If this is the case, and provided this animal or its production are intended for human consumption, one should be able either to analyze tissues and fluids for toxin residues or to monitor fluids (plasma, milk, urine) to determine whether this animal or its productions can be considered safe for human consumption. There are very limited examples of such occurrences. In our laboratory, we analyzed muscular tissues after a confirmed yew tree poisoning case (Taxtis baccata). Three animals did not display any significant trouble except for a transient depression, which resolved itself after 12 h. These animals were butchered and muscle samples were analyzed for taxin residues, as they were known to be exposed to it. Our analytical technique (extraction in alkalinized methylene dichloride) followed by TLC development based on a modification of a published technique (9685), showed that the muscle samples contained between 0.012 and 0.015 j.g/g taxin (wet weight). The presence of taxin in muscle tissues had never been previously reported in cattle after moderate poisoning. Based on this result, the meat was... 

CGA 92194, N-(l,3-dioxolan-2-yl)methoxyimino(phenyl)acetonitrile (oxa-betrinil, 20) is a white crystalline powder insoluble in water, soluble in methylene dichloride. It is practically not toxic to mammals. Acute oral lDjo for rats is 5000 mg. 

Classification Halogenated hydantoin Empirical C5H6BrCIN202 Formula BrCI(CH3)2C3N202 Properties Wh. powd., faint halogen odor sol. in benzene, methylene dichloride, chloroform m.w. 241.49 m.p. 163-164 C Toxicology LD50 (oral, rat) 485 mg/kg LDLo (skin, rabbit) 2 g/kg mod. toxicity by skin contact and ing. primary irritant severe eye and skin irritant TSCA listed Hazardous Decomp. Prods. Heated to decomp.. 

Chlorinated hydrocarbons n. Powerful solvents, which include such members as chloroform, carbon tetrachloride, ethylene dichloride, methylene chloride, tetrachor-ethane, trichloroethylene, etc. Generally speaking, they are toxic. Their main applications include non-flammable paint removers, cleaning solutions, and special finishes where presence of residual solvent in the film is a disadvantage. Many are not prohibited in most countries. 

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