Carbamate pesticide, liquid

Carbamate pesticides, liquid, flammable, toxic, n.o.s., flashpoint less than 23 °C. 2758... 

Calcium Bisulfite Solution 2693 60 Carbamate Pesticides, liquid, toxic. 2991 28... 

CARBAMATE PESTICIDES, FLAMMABLE, LIQUID, TOXIC, n.O.S., CARBAMATE PESTICIDES, FLAMMABLE, LIQUID, TOXIC, n.O.S.,... 

Mayer, W. J. and Greenberg, M. S., Determination of some carbamate pesticides by high-performance liquid chromatography with electrochemical detection, ]. Chromatogr., 208, 295, 1981. 

Liquid-liquid extraction has also been employed as a cleanup step, with separations being made between an acid or alkaline aqueous phase and an organic solvent (48). This procedure takes advantages of differences in the physical and chemical characteristics between the carbamate and the substrate. Another commonly used procedure is based on the generally high solubility of carbamates in polar solvents and their low solubility in saturated hydrocarbons. Table 5 summarizes the use of the various cleanup procedures in the determination of carbamate pesticides. 

CM Sparacino, JW Hines. High-performance liquid chromatography of carbamate pesticides. J Chromatogr Sci 14 549-556, 1976. 

McGarvey [304] has reviewed high-performance liquid chromatographic methods of determining 31 AT-methylcarbamate pesticides in soil, and Oka-moto et al. [305] used automated solid-phase extraction followed by on-line high-performance liquid chromatography to determine ten carbamate pesticides in soil. 

Synonyms isocyanic acid methyl ester, isocyanatomethane, MIC Formula CH3NCO MW 57.05 CAS [624-83-9] used in the manufacture of carbamate pesticides colorless liquid with an unpleasant odor boils at 39°C freezes at -80°C vapor pressure 400 torr at 20°C density 0.96 g/mL at 20°C vapor density 1.97 (air= 1) decomposes in water soluble in most organic solvents highly toxic and flammable. 

Nerve Agents are the most toxic of the known chemical agents. Solids, liquids or vapors from these agents are hazardous and can cause death within minutes after exposure. Nerve Agents disrupt the function of the nervous system by interfering with the enzyme acetylcholinesterase. The major effects will be on skeletal muscles, certain organs, and the central nervous system. These compounds are similar to, but much more deadly than, agricultural carbamate pesticides. 

Carbamate pesticides can be either solids or liquids with varying colors and odors. These pesticides are also found as solutions. 

Sanchez-Brunete, C., Rodriguez, A., and Tadeo, J. L., Multiresidue analysis of carbamate pesticides in soil by sonication assisted extraction in small columns and liquid chromatography, J. Chromatogr. A, 1007, 85-91, 2003. 

The procedure to be used to extract carbamate pesticides from environmental samples depends on their polarity and on the type of sample matrix involved. Various choices exist for the extraction of pesticides ranging from conventional procedures (e.g., Soxhlet extraction, liquid-liquid extraction (LLE), evaporation, steam distillation) to new methodologies including solid-phase extraction (SPE), solid-phase microextraction (SPME), supercritical fluid extraction (SEE), matrix solid-phase dispersion (MSPD), accelerated solvent extraction (ASE) and microwave-assisted extraction. " ... 

LLE is a widely used technique among the official US-EPA methods for the preconcentration of pesticides in liquid samples. Nonpolar solvents for the LLE of pesticides include w-hexane, benzene, and ethyl acetate. Water-miscible solvents for this purpose include dichloromethane, methanol, acetonitrile, acetone, and water, which have been employed for the extraction of residues from high-moisture commodities. Mixed solvents have often been used to finely adjust the solvent strength. Thus, various carbamate pesticides were extracted from aqueous environmental samples with chloroform and determined by HPLC with a mean recovery of 71 Also, a method based on the extraction by sonication of solid samples placed in small columns with a low volume of ethyl acetate was developed for the extraction of thiocarbamates and other herbicides from soil with recoveries between 89 and 109%. ... 

Analytical Methods for the Pretreatment of Environmental Samples and Liquid Chromatographic Determination of Carbamate Pesticides... 

MS is becoming the detection system of choice for LC by virtue of its flexibility and high selectivity for individual solutesHowever, LC-MS is always less sensitive than GC-MS as a result of the need to transfer the analytes from the liquid phase into a high-vacuum gas phase. Other limitations of LC-MS combination include the inability to use nonvolatile buffers, the narrow optimum range for eluent flow rate influence of the proportion of organic modifier on the sensitivity, and the narrow choice of ionization methods.Nevertheless, LC-MS has been widely accepted as an advantageous choice for the determination of carbamate pesticides in water matrices, which is more robust and flexible in the absence of derivatization. Thermospray and particle-beam interfaces are probably most commonly used for offline and online determination of carbamates in Atmospheric pressure sources such as... 

Number of carbamate pesticides (see Table 24.1) other other noncarbamate pesticides LLE liquid-liquid extraction SPE solid-phase extraction... 

Soriano, J. M., Jimenez, B., Font, G., and Molto, J. C., Analysis of carbamate pesticides and their metabolites in water by solid phase extraction and liquid chromatography a review, Crit. Rev. Anal. Chem., 31, 19-52, 2001. 

Slobodnik, J., Hoekstra-Oussoren, S. J. F., Jager, M. E., Honing, M., van Baar, B. L. M., and Brinkman, U. A. Th., Online solid-phase extraction-liquid chromatography-particle beam mass spectrometry and gas chromatography-mass spectrometry of carbamate pesticides. Analyst, 121, 1327-1334, 1996. 

Thurston, A. D., Liquid Chromatography of Carbamate Pesticides, EPA-R2-72-079, National Environmental Research Center, U.S. Environmental Protection Agency, Corvallis, 1972. 

Fogy, I., Schmid, E. R., and Huber, J. F. K., Determination of carbamate pesticides in fruits and vegetables by multidimensional high-pressure liquid chromatography, Z. Lebensm. Unters. Forsck, 170, 194-199, 1980. 

Garcia de Llasera, M. P. and Bemal-Gonzalez, M., Presence of carbamate pesticides in environmental waters from the Northwest of Mexico determination by liquid chromatography. Water Res., 35, 1933-1940, 2001. 

Anderson, J. L. and Chesney, D. J., Liquid chromatographic determination of selected carbamate pesticides in water with electrochemical detection. Anal. Chem., 52, 2156-2161, 1980. 

Anderson, J. L., Whiten, K. K., Brewster, J. D., Ou, T. Y., and Nonidez, W. K., Micro-array electrochemical flow detectors at high applied potentials and liquid chromatography with electrochemical detection of carbamate pesticides in river water. Anal. Chem., 57, 1366-1373, 1985. 

In Bhopal, MIC used to be stored in steel tanks for the manufacture of the carbamate pesticide carbary) (Sevin). The disaster was caused by the entry of water into the MIC-containing lank No. 610. The exothermic reaction between water and MIC converted liquid MIC into vapor, generating enough heal and pressure tt> burst open the vent. MIC vapor was discharged in the atmosphere, and because it was heavier than air it descended on the densely populated areas people were awakened by a choking sensation and eye irritation (Varma, 1986). 

Kawasaki, S., Nagumo, F., Ueda, H., Taijima, Y., eial. (1993). Simple, rapid, and simultaneous measurement of eight types of carbamate pesticides in serum using liquid chromatography-atmospheric pressure chemical ionization ma,ss spectrometry. J. Chromatogr. Biomed. Appl. 620, 61-71. 

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