Pentachlorophenol detection limit

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. 

These listed wastes also must be treated below detection limits for 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, and pentachlorophenol. The detection limits for these constituents are 50, 50, 100, and 10 ppb, respectively, in the waste extracts using methods 3510/8270 identified in SW-846. 

Especially for higher concentrations of biocides in air, impinging methods are an alternative. Pentachlorophenol concentrations can be analyzed after passing the air through an aqueous alkaline solution. A similar method has been reported for carbaryl and baygon. These biocides were absorbed in a sodium hydroxide solution and the hydrolysis products coupled to p-aminoacetophenol. The resulting dye could be spectrophotometrically quantified at A = 580 or 555 nm with a detection limit of about... 

A short review of methods for the analysis of biocides in household dust is given in Table 3.5-2. Most methods use either toluene or ethyl acetate for the extraction of organic compounds. In some cases, especially for methods having low detection limits, an additional clean-up with Florisil or silica gel is added. Methods of quantifying the substances of interest in the (cleaned) extract are either GC-ECD or GC-MS. All procedures are rather similar for carbamates, organochlorine compounds, organophosphates and pyre-throids. For the analysis of some phenols, e.g. pentachlorophenol, a derivatization step (alkylation, acetylation) is necessary. 

NOTE N/A, not applicable N/R, not reported and N/D, not detected. Explosives detection limits at Porton Down 50 mg/L for HMX, RDX, TNT, tetryl 65 mg/L for nitrocellulose 30 mg/L for nitroglycerin. Semivolatile organics (SVOCs) analyzed at Poiton Down 1,4-dichlorobenzene, 2,4- and 2,6-dinitrotoluene, hexachlorobutadiene, nitrobenzene, o-cresol, pentachlorophenol, pyridine, 1,2,4-trichlorobenzene, 2,4,5- and 2,4,6-trichlorophenol. Detection limit on all SVOCs except pyridine was 0.6 mg/L that for pyridine was 0.7 mg/L. Volatile organics (VOCs) analyzed at Potion Down benzene, carbon tetrachloride, chlorobenzene, chloroform, 1,4-dichlorobenzene, 1,2-dichloroethane, 1,1-dichloroethylene, 1,1,1,2- and 1,1,2,2-tetrachloroethane, trichloroethylene, 2-butanone (methyl ethyl ketone (MEK)), and vinyl chloride. Detection limit was 1 mg/L on all VOCs. 

Contaminants adversely affect the sensitivity of detection of the active agents, especially in wood extracts the limits of detection are consequently rather high (5 jxg for y-BHC and pentachlorophenol, 2 [xg for monochloronaphthalene). As has been shown by Petrowitz, the inclusion of new types of fluorescent dye in the layers also does not increase sensitivity. The procedures in Section IV, p. 77 may be used for visualising the individual substances. 

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