27 phenols including mono- di-, tri-, tetra- and pentachlorophenols, mono- and dinitrophenols, mono- and dinitrocresols and dimethylnitrophenols have been extracted from aqueous samples by solid phase extraction using both modified silica gel (C18) and XAD resin-ad-sorbents and determined by gas chromatography (GC) using capillary columns with specially desactivated weakly polar phases. If a 1 l sample of spiked water is used, a considerable breakthrough is observed with phenol itself, while all other phenols are almost quantitatively extracted. The recovery of phenol itself can be improved by employing smaller sample volumes
Summary:Waste water from ammunition production sites and aqueous samples (ground and surface water) on or near former military sites on which explosives were produced or filled, e.g. into shells, may be contaminated by the original explosives-mainly nitrotoluenes (such as dinitrotoluenes, trinitrotoluene (TNT)) and nitramines (such as hexogen (RDX), octogen (HMX), and tetryl) or hexyl, but also by byproducts and compounds formed by biodegradation of the explosives such as aminonitrotoluenes, chlorinated nitrobenzenes and nitrophenols. These compounds can be extracted from aqueous samples by liquid/liquid extraction (using dichloromethane or toluene) or by solid phase extraction using C-18 adsorbents with high recoveries (usually 2 85%) provided they contain only one amino group. Nitrotoluenes, chlorinated nitrobenzenes and aminonitrotoluenes (nitrotoluidines) may be determined by gas chromatography (GC) using selctive detectors such as an electron capture detector (ECD), a nitrogen-phosphorus detector (NPD) or a chemiluminescence detector (thermal energy analyzer, TEA). The use of combined gas chromatography/mass spectrometry (GUMS) under electron impact conditions is even more specific. Detection limits comparable to an ECD or NPD, however, are only achieved if the mass spectrometer is operated under selected ion monitoring (SIM). Nitrophenols are derivatized after extraction by heptafluorobutyric anhydride or by acetic anhydride where the latter method can be directly applied to the aqueous sample. The nitramine explosives, such as RDX, HMX, and tetryl, hexyl, the nitrate esters, such as nitropenta (PETN) and nitroguanidine as well as picric acid cannot, or only with difficulty, be analyzed by gas chromatography. They may be determined by high performance liquid chromatography (HPLC) with UV-detection. The HPLC analysis can be extended to include also nitrotoluenes and nitroaminotoluenes.
Cloud and rain water samples have been collected in spring 1991 in the Vosges mountains (France) and analyzed for aldehydes, phenols and polycyclic aromatic hydrocarbons (PAHs). Both passive and active cloud collectors have been employed. A mean concentration of formaldehyde of 197 pgA (6.6 pM) has been found in cloud water while on the average only 100 pdl(3.3 pM) were observed in rain water. The average phenol concentration was 3.5 pg/l(37 nM), but only 1.6 pdl(17 nM) in rain water. Finally, the mean concentration of PAHs (only determined in cloud water) amounts to 0.37 pgA. The PAH profile is similar to that observed for rain water sampled in Hannover (Germany).
Methods for the determination of three compound classes, i. e. diaminotoluenes, nitrophenols, and chloroaromatics in groundwater of a former ammunition plant are reported. Diaminotoluenes were extracted by discontinuous liquid/liquid-, nitrophenols by continuous liquid/liquid-extraction using dichloromethane, and chloroaromatics by solid-phase extraction. These compound classes may be analyzed by gas chromatography (GC) or gas chromatography coupled to mass spectrometry (GUMS) without derivatization or after derivatization with N-methyl-bis(triflu0roacetamide) (MBTFA) or heptafluorobutyric anhydride (HFBA) in the case of diaminotoluenes and HFBA or acetic anhydride in the case of nitrophenols. An atomic emission detector (AED) coupled to a gas chromatograph may be employed for the analysis of chloroaromatics. High selectivity can be achieved using the characteristic wavelengths of chlorine. A variety of these compounds were identified and quantified in a groundwater sample from the former ammunition plant Elsnig (Saxony, Germany). Concentrations were in the lower ppb range. Thus, dichlorobenzenes which may have been used as substituents at the end of World War I1 could be identified in groundwater samples at this site.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.