Herbicides chlorinated

B. Richter, J. EzzeU, and D. Felix, Single Laboratory Method Validation Report Extraction of Organo-phosphorus Agrochemicals, Chlorinated Herbicides and Polychlorinated Biphenyls Using Accelerated Solvent Extraction (ASE) with Analytical Validation by GC/NPD and GC/ECD, Document 101124, Dionex Sunnyvale, CA (1994). 

Accelerated solvent extraction is a new technique for the extraction of a range of organic pollutants from soils and related material. The technique is based on the use of a solvent or combination of solvents to extract organic pollutants at elevated pressure and temperature from a solid matrix. The range of organic pollutants for which the technique is proposed includes semivolatile compounds, organochlorine pesticides, organophosphorus pesticides, chlorinated herbicides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons [53-56],... 

Tanaka. F.S., Hoffer, B.L., and Wien. R.G. Detection of halogenated biphenyls from sunlight photolysis of chlorinated herbicides in aqueous solution. Pestle. Scl, 16(3) 265-270, 1985. 

Monochlorophenols represent an important class of environmental water pollutants of moderate toxicity to mammalian and aquatic life they possess relatively strong organoleptic effects, with taste thresholds of 0.1 pg/L (ppb). Their principal sources are the natural degradation of chlorinated herbicides (e.g., chlorophenoxyacetic acids), chlorination of phenolic substances in waste effluents, and chlorine treatment of drinking water. Of the three chlo-rophenols examined here, 3-chlorophenol exhibited the greatest resistance to sonolysis. 

The range of materials for which the technique is proposed includes semivolatile compounds, including polycyclic aromatic hydrocarbons, organochlo-rine pesticides, organophosphorus pesticides, chlorinated herbicides and polychlorinated biphenyls [92],... 

Chlorophenoxy acids are one of the most important classes of chlorinated herbicides. In these compounds, chlorosubstituted benzene rings are attached to lower carboxylic acids via an oxygen atom, as shown in the following structures ... 

Highly selective to halogenated and oxygenated compounds Electron capture detector EDB, DBCP (EPA 8011) Acrylamide (EPA 8032) Phenols (EPA 8041) Phthalates (EPA 8061) Organochlorine pesticides (EPA 8081) PCBs (EPA 8082) Nitroaromatics and cyclic ketones (EPA 8091) Haloethers (EPA 8111) Chlorinated herbicides (EPA 8151) CLP SOW for organic analysis Interferences from Elemental sulfur (S8) Waxes, lipids, other high molecular weight compounds Phthalate esters, which are common laboratory contaminants Oil in PCB analysis... 

The HPLC/MS technique used in EPA Method 8321 is best suited for analysis of thermally unstable compounds that are hard to analyze with conventional GC methods, such as organophosphorus pesticides, chlorinated herbicides, and carbamates. In this technique, the detection with mass spectrometry provides the ultimate selectivity. The sensitivity for each individual compound depends on the interferences in a given environmental matrix and on the chemical nature of the analyte. 

Second column confirmation must be used in pesticide, PCBs, and chlorinated herbicide analyses by EPA Methods 8081, 8082, and 8151, respectively. In these methods, two columns with dissimilar polarities and two ECDs provide compound identification and quantitation. This technique produces a lower rate of false positive results, but does not eliminate them completely. This is particularly true for low concentrations of pesticides and herbicides, where non-target compounds, such as constituents of the sample matrix or laboratory artifacts listed in Table 4.3, produce chromatographic peaks on both columns. These interference peaks cannot be distinguished from the target analytes based on retention time only and cause false positive results. 

Chlorinated herbicides SW-846 3510/8151 SW-846 3520/8151 One liter amber glass, PTFE-lined lid 1000 ml 2 to 6°C 7 days for extraction, 40 days for analysis... 

Chlorinated herbicides Acetone-methylene chloride-phosphoric acid solution (250 125 15 v/v/v) or acetone-methylene chloride-trifluoroacetic acid solution (250 125 15 v/v/v)... 

A number of cohort studies on workers exposed to PCDD/Fs during the manufacture of chlorinated herbicides or phenols have been reported. Analysis of the cancer mortality data from 5712 workers in herbicide manufacturing plants in... 

Analysis of Chlorinated Herbicides by High-Performance Liquid Chromatography/Mass Spectrometry... 

TABLE IIL limits of Detection in the Positive and Negative Ion Modes for the Chlorinated Herbicides... 

The information generated in the MS/MS mode of operation of the triple quadrupole mass spectrometer for these chlorinated herbicides is typified by the spectrum shown in Figure 4. This figure represents the daughter ion CAD spectrum of the m/z 266 ion from 2,4-DB. The (M+NH4)+ ion at m/z 266 was generated in the buffer assisted ion evaporation of 2,4-DB. Losses of OH (or NH3), Cl (or NH3 and H20), and (CHj),COOH NH4 from the ammoniated species comprise the majority of the ions in the spectrum (CH2)3COOH is the base peak. Since the m/z 266 ion has only contributions from Cl, the CAD spectrum is not marked by the chlorine isotopic pattern that these herbicides usually show (see Figure 2). Consequently, a simpler spectrum results. 

Attempts to increase the voltage on the wire-repeller above the value that maximized the sensitivities for these compounds resulted in additional fragmentation of the chlorinated herbicides. The wire-repeller was also moved closer to the sampling... 

Pesticides (chlorinated herbicides) Glass Cool to 4 C, seal, add HQ to pH < 2 (500 ml of water) 14 days... 

Solvent type Acetone hexane (1 1 (vol/vol)) acetone DCM (1 1 (vol/vol)) DCM only toluene methanol (10 l(vol/vol)) alternatively, a solvent system of your own choice As Soxhlet As Soxhlet Requires optimization CO2 (plus organic modifier). Tetra- chloroethene used as the collection solvent for TPHs for determination by FTIR otherwise, DCM Typically, acetone hexane (1 1 (vol/vol)). The solvent(s) is/are required to be able to absorb microwave energy Acetone hexane (1 1 (vol/vol)) or acetone DCM (1 1 (vol/vol)) for OCPs, semi-volatile organics, PCBs or OPPs acetone DCM phosphoric acid (250 125 15(vol/vol)) for chlorinated herbicides... 

Are there any places in your areas where the groundwater is contaminated with trichloroethylene, perchloroethylene, chlorinated herbicides, or chlorinated insecticides If so, do any of them require treatment ... 

Occupations Firefighters (transformer/capacitor fires) Hazardous waste cleanup crews Manufacturers of chlorinated herbicides, germicides, and organic solvents Municipal/waste incinerator workers Utility workers working in or spraying herbicides along rights-of-way Vietnam War veterans... 

Microwave Extraction of VOC s and SVOC s (organophosphorus pesticides, organochlorine pesticides, chlorinated herbicides, phenoxy acid herbicides, PCBs, etc.), EPA Method 3546, EPA SW-846 update III, US Environmental Protection Agency, 1999. 

EPA Method 8151, Chlorinated Herbicides By Gc Using Methylation Orpentafluorohenzylation... 

ORIGIN/INDUSTRY SOURCES/USES not produced or commercially used in U.S. formed in the production of 2,4,5-trichlorophenol and of a few chlorinated herbicides such as silvex formed during combustion of chlorinated organic compounds impurity in pesticides has been tested for use in flameproofing polyesters tested as an insecticide used as a defoliant in Vietnam War... 

Halogenated aromatic compounds O-CH2COOH Chlorinated herbicides... 

Tanaka, F.S., B.L. Hoffer, and R.G. Wien. Detection of Halogenated Bipheityls from Sunlight Photolysis of Chlorinated Herbicides in Aqueous Solution, Pestic. Sci., 16 265-270 (1985). 

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