Pesticide carbamate

WHO Environmental Health Cdteda, Carbamate Pesticides, Geneva, Switzedand, 1986. 

High performance Hquid chromatography with electrochemical detection has been used to determine 2—7 ppb of carbamate pesticides in water (40). The investigated pesticides were aminocarb, asulam, j -butylphenyknethylcarbamate (BPMC), carbaryl, carbenda2im, chlorpropham, desmedipham, and phenmedipham. 

Reaction with Amines and Ammonia. Carbonates react with amines and ammonia to produce carbamates or ureas. This reaction can be used as an alternative route to producing carbamate pesticides. 

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

Detection limits of 250 ng per chromatogram zone have been reported for THC-11-carboxylic acid [15] and of 500 ng per chromatogram zone for carbamate pesticides [19]. 

Toxin (Enzyme Inhibition) Biosensors Enzyme affectors (inhibitors and activators) that influence the rate of biocatalytic reactions can also be measured. Sensing probes for organophosphate and carbamate pesticides, for the respiratory... 

In the case of carbamate pesticides the chromatogram is heated to 150 °C for 20 min after the application of the reagent. Spraying later with a solution of 2 N sodium hydroxide solution to improve the color contrast is recommended [15]. Occasionally a small amount of iron(III) chloride is added to the reagent [13]. 

Belisle AA, Swineford DM. 1988. Simple, specific analysis of organophosphoms and carbamate pesticides in sediments using column extraction and gas chromatography. Environ Toxicol Chem 7 749-752. 

Faust SD, Gomaa HM. 1972. Chemical hydrolysis of some organic phosphorus and carbamate pesticides in aquatic environments. Environ Lett 3 171 -201. 

Mendoza CE, Shields JB. 1971. Esterase specificity and sensitivity to organophosphorus and carbamate pesticides Factors affecting determination by thin layer chromatography. J Assoc Off Anal Chem 54 507-512. 

Environmental Health Criteria 64 Carbamate Pesticides A General Introduction. WHO Geneva, 1986. 

Mineau, P., Fletcher, M., and Glaser, L.C. et al. (1999). Poisoning of raptors with organophosphorous and carbamate pesticides with emphasis on Canada, U.S. and U.K. Journal of Raptor Research 33, 1-37. 

Rhodamine B vaseline [155] diphenyl, polyphenols [156] maleic and fu-maric acids [162] flavonoids [158] alcohols as 3,5-dinitrobenzoates [159, 160] gangliosides [161] 1-hydroxychlorden [162] carbamate pesticides [163] para-thion and its metabolites [164] polyethylene and polypropylene glycols [165] terpene derivatives [166] menthol [167]... 

Attempts have been made to apply the structure-activity concept (Hansch and Leo 1995) to environmental problems, and this has been successfully applied to the rates of hydrolysis of carbamate pesticides (Wolfe et al. 1978), and of esters of chlorinated carboxylic acids (Paris et al. 1984). This has been extended to correlating rates of biotransformation with the structure of the substrates and has been illustrated with a number of single-stage reactions. Clearly, this approach can be refined with the increased understanding of the structure and function of the relevant degradative enzymes. Some examples illustrate the application of this procedure ... 

Wolfe NL, RG Zepp, DE Paris (1978) Use of structure-reactivity relationships to estimate hydrolytic persistence of carbamate pesticides. Water Res 12 561-563. 

Chohnesterase-inhibiting pesticides (e g., organophosphate and carbamate pesticides) are detected by dipping the developed chromatogram in a solution of the enzyme chohnesterase followed by incubation for a short period. Then the plate is dipped in a substrate solution, e.g., 1-naphthyl acetate/fast blue salt B. In the presence of the active enzyme, 1-naphthyl acetate is hydrolyzed to 1-naphthol and acetic acid, and the 1-naphthol is coupled with fast blue salt B to form a violet-blue azo dye. The enzyme is inhibited by the pesticide zones, so the enzyme-substrate reaction does not occur pesticides are, therefore, detected as colorless zones on a violet-blue background [36]. 

Lord and Pawliszyn" developed a related technique called in-tube SPME in which analytes partition into a polymer coated on the inside of a fused-silica capillary. In automated SPME/HPLC the sample is injected directly into the SPME tube and the analyte is selectively eluted with either the mobile phase or a desorption solution of choice. A mixture of six phenylurea pesticides and eight carbamate pesticides was analyzed using this technique. Lee etal. utilized a novel technique of diazomethane gas-phase methylation post-SPE for the determination of acidic herbicides in water, and Nilsson et al. used SPME post-derivatization to extract benzyl ester herbicides. The successful analysis of volatile analytes indicates a potential for the analysis of fumigant pesticides such as formaldehyde, methyl bromide and phosphine. 

ESI performs well for the more polar compounds such as imidazolinone herbicides, sulfonylurea herbicides, triazine herbicides, phenoxy acid herbicides, and carbamate pesticides (to name a few). ESI also performs well with proteins and peptides. 

In this study, the preliminary findings showed that the HPLC/fluorescence data were in agreement for all 12 carbamates with HPLC/ESI-MS/MS for most of the nine fruits and vegetables at the 1.0 ng g fortification level. The recoveries were generally within 70-120% however, at the 1.0 ng g level in each commodity, HPLC/ESI-MS (single-stage MS) had difficulty with interferences for three out of the 12 carbamate pesticides (aldicarb sulfoxide, aldicarb sulfone, and 3-hydroxycarbofuran), which made quantification impossible for these three compounds. 

E.B. Tribaldo, Residue analysis of carbamate pesticides in water, in Food Science Technology, Marcel Dekker, New York, pp. 537-570 (2000). 

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

---