Pentachlorophenol , extraction

Suzuki T (1978) Enzymatic methylation of pentachlorophenol and its related compounds by cell-free extracts of Mycobacterium sp isolated from soil. J Pesticide Sci 3 441-443. 

Apajalahti JHA, MS Salkinoja-Salonen (1987b) Complete dechlorination of tetrachlorohydroquinone by cell extracts of pentachlorophenol-induced Rhodococcus chlorophenolicus. J Bacterial 169 5125-5130. 

Wall, A.J. and G.W. Stratton. 1991. Comparison of methods for the extraction of pentachlorophenol from aqueous and soil systems. Chemosphere 22 99-106. 

Lopez-Avila et al. [36] used a stable isotope dilution gas chromatography-mass spectrometric technique to determine down to O.lppb of pentachlorophenol (also Atrazine, Diazinon and lindane) in soil. Soil samples are extracted with acetone and hexane. Analysis is performed by high-resolution gas chromatography-mass spectrometry with mass spectrometer operated in the selected ion monitoring mode. Accuracy greater than 86% and a precision better than 8% were demonstrated by use of spiked samples. 

Fig. 5.1 Extraction of Atrazine, lindane, pentachlorophenol and Diazinon from soil Source Reproduced with permission from the American Chemical Society [36]... 

Lee [42] determined pentachlorophenol and 19 other chlorinated phenols in sediments. Acidified sediment samples were Soxhlet extracted (acetone-hexane), back extracted into potassium bicarbonate, acetylated with acetic anhydride and re-extracted into petroleum ether for gas chromatographic analysis using an electron capture or a mass spectrometric detector. Procedures were validated with spiked sediment samples at 100,10 and lng chlorophenols per g. Recoveries of monochlorophenols and polychlorophenols (including dichlorophenols) were 65-85% and 80-95%, respectively. However, chloromethyl phenols were less than 50% recovered and results for phenol itself were very variable. The estimated lower detection limit was about 0.2ng per g. 

Fig. 20. A typical GC-MS trace of a phenol contaminated soil sample, Bitterfeld, Germany (after [254] with permission). Chlorophenols were extracted using ASE-SPME upper chromatogram, procedure B lower chromatogram, ASE conditions of water, 150°C, 15 min. Peak identifications (1) 2-chlorophenol, (2) 2,4-dichlorophenol, (3) 4-chlorophenol, (4) 4-chloro-3-methylphenol, (5) 2,3,5-trichlorophenol, (6) 2,4,6-trichlorophenol, (7) 2,3,4-trichlo-rophenol, (8) 2,3,4,6-tetrachlorophenol, (9) pentachlorophenol... 

Pentachlorophenol Soxhiet extraction using heptane or acetone/heptane (50 50) derivatisation with acetic anhydride quantification by means of GC-ECD or GC-MS E DIN ISO 14154 10.97... 

Pentachlorophenol was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum. Significant biooxidation was observed but with a gradual adaptation during a 14-d period to achieve complete degradation at 5 mg/L substrate cultures. At a concentration of 10 mg/L, it took 28 d for pentachlorophenol to degrade completely (Tabak et al., 1981). 

The Extraksol process can extract organic contaminants such as oils and greases, polynuclear aromatic hydrocarbons (PAHs), pentachlorophenols (PCPs), and phenols from a variety of solid matrices. The Extraksol process can extract polychlorinated biphenyls (PCBs) from clay-bearing soil, sand, and FuUer s earth. Extraksol has successfully treated various media such as activated carbons, refinery sludges, and wood treatment sludges. 

The desorption and vapor extraction system (DAVES) uses a low-temperature fluidized bed to remove volatile and semivolatile organics such as polychlorinated biphenyls (PCBs), polynuclear aromatic compounds (PAHs), pentachlorophenol (PCP), volatile inorganics (tetraethyl lead), and some pesticides from soil, sludge, and sediment. The process generally treats waste containing less than 10% total organic contaminants and 30 to 95% solids. The process does not treat nonvolatile inorganic contaminants such as metals. 

The extraction of pentachlorophenol (PCP) from pressure-treated wood wafers with supercritical carbon dioxide (SC-CO2) was studied in a continu-ons-flow extractor (Sahledemessie et al., 1997). 

Samples of sand spiked with 36 nitroaromatic compounds, 19 haloethers, and 42 organochlorine pesticides, and a standard reference soil (certified for 13 polynuclear aromatic hydrocarbons, dibenzofuran, and pentachlorophenol) were extracted with supercritical carbon dioxide in a two- or four-vessel supercritical fluid extractor to establish the efficiency of the extraction and the degree of agreement of the parallel extraction recoveries. Furthermore, the many variables that influence the extraction process (e.g., flowrate, pressure, temperature, moisture content, cell volume, sample size, extraction time, modifier type, modifier volume, static versus dynamic extraction, volume of solvent in the collection vessel, and the use of glass beads to fill the void volume) were investigated. 

Results. Tables m IV show the SFE-GC/MS results obtained for duplicate extractions of 14 PAHs plus pentachlorophenol from a EPA standard reference material soil sample. Table m lists the certified values of the analytes as determined by a standard method as well as the SFE recoveries for the individual fractions of sample 1, total recovery from SFE, and total percent recovery from SFE in relation to the certified values. Table IV shows the repeatability of the experiment by comparing total SFE recoveries from two identical sample extractions. 

Figure 15.13 Comprehensive two-dimensional GC chromatogram of a supercritical fluid extract of spiked human serum. Peak identification is as follows 1, dicamba 2, trifluralin 3, dichloran 4, phorate 5, pentachlorophenol 6, atrazine 7, fonofos 8, diazinon 9, chlorothalonil 10, terbufos 11, alachlor 12, matalaxyl 13, malathion 14, metalochlor 15, DCPA 16, captan 17, folpet 18, heptadecanoic acid. Adapted from Analytical Chemistry, 66, Z. Liu et al., Comprehensive two-dimensional gas chromatography for the fast separation and determination of pesticides extracted from human serum , pp. 3086-3092, copyright 1994, with permission from the American Chemical Society.

Methods of Extraction and Analyses. Chloropyrifos, Ronnel, chlorpropham and 2,4,5-T were extracted from the cloth or the cellulose pad with hexane. Pentachlorophenol residues were extracted with benzene. Pentachlorophenol was methylated with diazomethane prior to determination by gas chromatography while the other compounds were determined dirgctly. Dinoseb, on the other hand was extracted with chloroform and partitioned into 2% Na2 Co3 solution. The yellow extract was analyzed colorimetri-cally using the method of Potter (14). 

Pentachlorophenol is collected on a filter (cellulose ester membranej-bubbler sampler. It is then extracted with methanol and analyzed by HPLC-UV. Use of alternate sampling train, Zelllour filter, and silica gel tube have also been reported (Vulcan, 1982). 

During, R.A., X. Zhang, H.E. Hummel, J. Czynski, and S. Gath. 2003. Microwave-assisted steam distillation with simultaneous liquid/liquid extraction of pentachlorophenol from organic wastes and soils. Anal. Bioanal. Chem. 375 584—588. 

For example, the ratio of the n-octanol/watcr distribution coefficient of the nondissociated species to that of the ionic species is nearly 10,000 for 3-methyl-2-nitrophenol, but only about 1000 for pentachlorophenol because of the greater significance of the hydrophobicity of the ionized form of pentachlorophenol. The logarithm of the -octanol/water distribution coefficient of pentachlorophenol as the phenolate is about 2 (determined at pH 12, and 0.1 M KC1), which indicates significant distribution of the ionized form into the n-octanol phase [8,37], Extraction of such highly hydrophobic ionogenic organic compounds can result from mixed-mode mechanisms that incorporate both the hydrophobic and ionic character of the compound. 

Pentachlorophenol w-hexane - Electron Pentachlorophenol 0.1 pgL-1 capture acetylated with acetic anhydride, then w-hexane extraction, then GLC [302]... 

Many of the analytical procedures for pentachlorophenol in the recent literature do not call for a hydrolysis step prior to extraction of a urine sample. During the course of our research in the development of a reliable multi-residue procedure for chlorinated phenols, we found that much more pentachlorophenol could be extracted from the urine if the sample was hydrolyzed with hydrochloric acid (23). 

Samples are transferred to a separatory funnel, surrogates are added, and an immiscible solvent (dichloromethane, hexane, etc.) is added. The liquids are shaken vigorously for a few minutes and then allowed to rest until a separation between the two phases occurs. The solvent is removed and the extraction process is repeated twice more. The extracts are combined, dried over anhydrous sodium sulphate, and processed further (cleanup) as required. Some laboratories have automated this tedious procedure by performing extractions in bottles. In this case, solvent and water are placed in a bottle and rotated (windmill rotators) or shaken (platform shakers) for 1—2 h. The lack of vigorous shaking is replaced by an extended time for extraction. Liquiddiquid extraction is used for all semivolatile analysis (hydrocarbons >C12, PAH, pesticides, PCB, dioxins). By lowering the pH, extraction of phenols (pentachlorophenol) and acidic compounds (2,4-dichlorophenoxyacetic acid—2,4-D) will be enhanced. Increasing the pH will increase extractability of basic (aromatic amines) and neutral compounds (PAH). 

At 280 nm, the minimum detectable quantity of pentachlorophenol is approximately 50 ng. Greater sensitivity may be achieved by monitoring at 254 nm. With samples extracted into benzene, however, 280 nm is preferred because of the large extinction coefficient of benzene at 254 nm. 

For example, pentachlorophenol can be extracted from water samples with benzene [12]. To a preserved sample (volume <1 1), 30 ml of benzene are added and the mixture is stirred for 45 min. The benzene phase is transferred into a separating funnel and the extraction is repeated with 30 ml of benzene for 30 min and 10 ml of benzene for 10 min. Sodium sulphate, isopropanol and/or methanol is used to break any emulsion. The combined benzene extracts are further extracted once with 40 ml and twice with 30 ml of 0.1 MK2C03 solution. The aqueous phase is used for derivatization. 

Chau and Coburn [4] described the determination of pentachlorophenols (PCPs) in natural and industrial waters at 0.01 ppb levels. The PCPs are extracted into benzene and... 

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