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Analytical and Bioanalytical Chemistry (v.371, #5)
No Title by T. Scharnweber; M. Fisher; M. Suchànek; D. Knopp; R. Niessner (pp. 578-585).
Benzo[a]pyrenebutyric acid (B[a]PBA) has been synthesized and covalently coupled to bovine serum albumin to generate monoclonal antibodies (Mab). A competitive indirect enzyme-linked immunosorbent assay (ELISA) for polycyclic aromatic hydrocarbons (PAH) has been developed with Mab B[a]P-13. It was shown by testing with 21 parent PAH and 10 compounds carrying methyl, hydroxy, or butyric acid functions that the antibody had broad specificity. Highest affinity was found for four- to six-ring PAH. Different organic co-solvents were tested. No loss in sensitivity, compared with controls in PBS, were found with methanol, dimethyl sulfoxide, and glycerol at final concentrations of 5 to 10%. Further, an observation was made that a modification (fine-tuning) of the affinity and specificity of the antibodies was possible by changing the type of the added organic co-solvent. The high susceptibility of the ELISA with regard to inorganic ions might be an indication of a more hydrophilic binding pocket e.g. involving a π-cation interaction. Investigation of the effect of pH revealed that for pH between 6 to 9 there was no noticeable impairment. With an LOD as low as 30 pg per well for B[a]P the sensitivity of the ELISA is sufficient for analyses of solvent extracts of many environmental samples. As an example, the determination of a PAH sum parameter, given as B[a]P-equivalents, in crude aerosol extracts by both ELISA and HPLC revealed good correlation (r2=0.717) but approximately five-fold overestimation by the immunochemical method, obviously as a result of cross-reacting analytes.
HG/LT–GC/ICP–MS coupling for identification of metal(loid) species in human urine after fish consumption by J. Kresimon; U. Grüter; A. Hirner (pp. 586-590).
Human urine samples after fish consumption have been investigated by low-temperature gas chromatography with inductively coupled plasma mass spectrometric detection after sample derivatization by hydride generation (HG/LT–GC/ICP–MS). This analytical technique enabled the identification of organometal(loid) compounds in human urine; species of the six elements germanium, arsenic, selenium, tin, antimony, and mercury were determined.Three different organic selenium species, two germanium species, seven arsenic species, four tin species, five antimony species, and one species of mercury were found; 18 of the 22 species detected could be identified. The relative detection limits ranged between 2 and 12 pg x L–1 (x=element). These organometal(loid) compounds probably build up in the human body under the influence of micro-organisms, in the presence of hydrogen sulfide and methane, in the human intestine.
No Title by C. Zwiener; L. Kronberg (pp. 591-597).
A new analytical method has been developed for the determination of chlorinated and brominated hydroxyfuranones. The method is based on separation by GC and selective determination of the compounds by use of an ion-trap mass detector. MS–MS fragmentation in an ion-trap detector can be regarded as an alternative to high-resolution mass spectrometry. Unique precursor ions were selected from the EI mass spectra and product-ion patterns were studied for a variety of collision energies. From these data, abundant mass transitions were selected for quantification and confirmation of compound identity. The method was applied to a spiked sample of chlorine-disinfected drinking water and it was found that the GC–MS–MS procedure is at least as sensitive and selective as previously published methods.
No Title by Oliver Pfeifer; Ursula Lohmann; Karlheinz Ballschmiter (pp. 598-606).
Halogenated methyl-phenyl ethers (methoxybenzenes, anisoles) are ubiquitous organics in the environment although they are not produced in industrial quantities. Modelling the fate of organic pollutants such as halogenated anisoles requires a knowledge of the fundamental physico-chemical properties of these compounds. The isomer-specific separation and detection of 60 of the 134 possible congeners allowing an environmental fingerprinting are reported in this study. The vapor pressure % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfKttLearuavTnhis1MBaeXatLxBI9gBae % bbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr % 0xc9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8 % frFve9Fve9Ff0dmeaabaqaciGacaGaaeqabaqabeaadaaakeaacqWG % WbaCdaahaaWcbeqaaiabicdaWaaakmaaBaaaleaacqWGmbataeqaaa % aa!2D66! $$p^0 _L $$ of more than 60 and further physico-chemical properties of 26 available congeners are given. Vapor pressures % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfKttLearuavTnhis1MBaeXatLxBI9gBae % bbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr % 0xc9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8 % frFve9Fve9Ff0dmeaabaqaciGacaGaaeqabaqabeaadaaakeaacqWG % WbaCdaahaaWcbeqaaiabicdaWaaakmaaBaaaleaacqWGmbataeqaaa % aa!2D66! $$p^0 _L $$ , water solubilities % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfKttLearuavTnhis1MBaeXatLxBI9gBae % bbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr % 0xc9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8 % frFve9Fve9Ff0dmeaabaqaciGacaGaaeqabaqabeaadaaakeaacqWG % tbWudaWgaaWcbaGaem4vaCfabeaakmaaCaaaleqabaGaemitaWeaaa % aa!2D75! $$S_W ^L $$ , and n-octanol/water partition coefficients K ow were determined by capillary HR-GC (High Resolution Gas Chromatography) on a non-polar phase and by RP-HPLC (Reversed Phase High Performance Liquid Chromatography) on a C18 phase with chlorobenzenes as reference standards. From these experimental data the Henry's law constants H, and the gas/water K gw and gas/n-octanol K go partition coefficients were calculated. We found that vapor pressures, water solubilities, and n-octanol/water partition coefficients of the halogenated anisoles are close to those of the chlorobenzenes. A similar environmental fate of both groups can, therefore, be predicted.
No Title by H. Börnick; T. Grischek; E. Worch (pp. 607-613).
An analytical method based on solid-phase extraction (SPE) with a polymeric material, HPLC separation on a modified C18 material, and diode-array detection is presented for the determination of aromatic amines in the ng L–1-concentration range. These potentially toxic compounds in polluted water samples can be sampled by using SPE with an amino phase to clean the eluate. Column experiments were performed to characterize the transport behavior of aromatic amines in an aquifer sediment. For nineteen aromatic amines, linear correlations were found between the adsorption coefficient, Kd, estimated from column experiments, and capacity factors, k′, measured by isocratic reversed-phase HPLC (RPHPLC).
No Title by Tanja Twiehaus; Stephan Evers; Wolfgang Buscher; Karl Cammann (pp. 614-620).
An automated quasi-continuously-operating monitor has been developed for element-selective analysis of adsorbable organic halogens (AOX) in water. After extensive optimization the automatic method was applied to the analysis of standard solutions and real waste water samples to prove its analytical applicability.The new instrument is based on the element-selective analysis of halogens by means of a spectroscopic detection system consisting of a microwave-induced helium plasma excitation source (TM010-type; developed in this laboratory) and the plasma emission detector (PED) which operates with oscillating narrow-band interference filters. After enriching the organic components on activated charcoal and pyrolysis in an oxygen stream at 950 °C, in accordance with DIN/EN 38409,H14/1485, interfering CO2 and H2O gas generated during combustion is removed from the analytes in the so-called ELSA-system (element-selective AOX-analyzer). For focused injection into the plasma excitation source the analytes (hydrogen halides) are trapped in a deactivated fused silica capillary at –180 °C; this is followed by identification and quantification on the basis of element-specific emission of radiation in the VIS and NIR-region (chlorine 837.6 nm, fluorine 685.6 nm).Bromine and iodine could not be detected with satisfactory inter-element selectivity, because of spectral interferences caused by matrix elements, and so results from the respective single-element investigations for determination of AOBr and AOI are not presented. The procedure has been validated and the analytical performance has been examined by calibration with p-chlorophenol and p-fluorophenol. The limit of detection was 1.1 µg (absolute) for chlorine and 6.6 µg (absolute) for fluorine.
No Title by Stefan H. Bossmann; Sabine Göb; Till Siegenthaler; André M. Braun; Koodali T. Ranjit; Itamar Willner (pp. 621-628).
The photocatalytic activity of TiO2 (Degussa P-25) modified with a 4,4′-bipyridinium monolayer (V2+-TiO2) has been compared with that of conventional TiO2-P-25 by investigating the efficiency of degradation of a series of four organic model compounds with increasing π-donor capacity (2,4-xylidine, 2,4-dimethylphenol, hydroquinone, and dimethylhydroquinone). As far as the mechanism of the first oxidation reaction is concerned, evidence for the formation of supramolecular donor–acceptor complexes with the bipyridinium units at the semiconductor surface was obtained by comparison of the Langmuir-adsorption characteristics and the efficiencies of photodegradation of the different substrates. Furthermore, the main intermediates of the photocatalytic degradation of 2,4-xylidine were identified, and the presence of 2,4-dimethylphenol indicates that the main pathway of substrate oxidation proceeds via electron transfer from the adsorbed organic substrate to the "holes" within the valence band of the photoexcited semiconductors V2+-TiO2 and TiO2. The efficiencies of photocatalytic degradation by both V2+-TiO2 and TiO2 were limited by the trapping efficiency of the conduction band electrons by molecular oxygen.
No Title by Dietrich Maier; Matthias Maier; Frank Oberacker (pp. 629-636).
The Marsh Test, the original means of determination of arsenic by hydride generation, has been modified to remove arsenic from water works sludge, with iron used instead of zinc as the main agent. Water works sludge (main compound iron(III) oxyhydrate) generated during groundwater treatment can be enriched in arsenic up to several g kg–1. Acidic dissolution of this sludge to produce FeCl3 coagulant liberates the arsenic. Addition of elemental iron reduces this dissolved As(V) mainly to dispersed elemental As(0) particles, which can be removed by filtration. If the reaction temperature is kept below 50 °C, more than 99% of the arsenic can be removed from the coagulant solution and less than 10% will escape as gaseous arsine (AsH3). Severe foaming and silicic acid gel formation occurs during the acidic dissolution, however. For technical and economic reasons the use of the water works sludge for FeCl3 coagulant production is not competitive when compared with other recycling methods.
No Title by German Müller; Ralf Ottenstein; Alfred Yahya (pp. 637-642).
Despite the manifold factors that determine the composition of a river sediment (e.g., geology, soil type, rural or highly industrialized and densely populated, as well as forested areas, concentration of carbonates and organic matter), the linear regressions between the 9 metals determined in the fractions <2 µm and <20 µm have high coefficients (R 2 after Pearson) for Cr and Cu (both 0.94), followed by Pb (0.90), Cd (0.82), Zn (0.81), Ni (0.76), and Mn (0.72). Low and very low coefficients are found for Hg (0.51) and Fe (0.22). In addition, the histograms of the metal ratios <2 µm:<20 µm (i.e. the slope of a linear regression) show that – with the exception of Cd (1.47) – all median ratios of the other metals fall within a narrow range (1.24–1.35).Both "fine"(<2 µm and <20 µm) fractions are able to fulfil the requirements for monitoring, inventory, and assessment of metals in sediments. Preference should be given to the rapid, simple, and economic <20 µm separation by sieving; this fraction corresponds fairly closely to the former suspended load of a riverine transport.
No Title by J. Einax; V. Nischwitz (pp. 643-651).
Two approaches have been used to investigate changes in the nature of metal binding in river sediments caused by atmospheric oxygen. Firstly, non-inert and inert sample preparation were applied, in combination with sequential extraction, to determine for which metals inert sample preparation is necessary for correct determination of metal mobility under environmental conditions. Secondly, the metal contents of sediments sampled before and after a river weir were fractionated by sequential extraction to study the effect of the oxygen impact at the weir on heavy metal mobility in the sediments. Different grain-size fractions from one sample were also extracted, to enable selection of the upper grain-size limit most suitable for answering this analytical question. The results showed the need for the inert sample preparation technique for Cd, Zn, Pb, Mn, and Fe, but not for Co, Ni, Cu, and Cr. No significant change of heavy metal mobility at the weir could be proved, although the mobilization behavior of some elements was different. The optimum upper grain-size limit was 63 µm.
No Title by U. Förstner; P. Jacobs; F. Kammer (pp. 652-659).
The retention of lead in zeolite-supported sand-filter columns has been tested with focus on the effect of potentially mobile natural nanophases (natural colloids, humic substances). It could be shown that interaction of lead with natural nanophases enhanced the mobility of the contaminant. In the presence of iron oxide particles (goethite) a normal breakthrough of lead was observed. Humic substance can act as a carrier for lead itself and can enhance the mobility of lead bound to inorganic nanophases, because of the increased mobility of the nanophases in the presence of humic substances.
No Title by Peter Burba; Johan Van den Bergh; Dieter Klockow (pp. 660-669).
Humic-rich hydrocolloids and their metal loading in selected German bog-waters have been characterized by a novel on-site approach. By use of an on-line multistage ultrafiltration (MST-UF) unit equipped with conventional polyethersulfone (PES)-based flat membranes (nominal cut-off 0.45, 0.22, and 0.1 µm, or 100, 50, 10, 5, 3 kDa) the hydrocolloids could be fractionated on-site in both sub-particulate and macromolecular size ranges. Characterization (dissolved organic carbon (DOC), metals) of the colloid fractions obtained this way was performed off-site by use of conventional instrumental methods (carbon analyzer, AAS, ICP–OES, and TXRF (total reflection X-ray fluorescence)). Major DOC fractions of the hydrocolloids studied were found to be in the size range <5 kDa. The assessed metals (Al, Cu, Fe, Mn, Pb, and Zn) were, however, predominantly enriched in the macromolecular and sub-particulate range, depending on the metal and the sample, respectively. In addition, metal species bound to these hydrocolloids were kinetically characterized on-site by use of competitive ligand (EDTA (ethylenediaminetetraacetate)) and metal (Cu(II)) exchange; the EDTA complexes formed and the metal ions exchanged were separated by means of a small time-controlled tangential-flow UF unit (cut-off 1 kDa). Bound metal fractions, in particular Al and Fe, reacted only slowly (500 to 1000 min) with EDTA; the conditional availability was 60–99%, depending on the hydrocolloid. In contrast, the Cu(II) exchange of colloid-bound metal species approached equilibrium within 5–10 min, with characteristic exchange constants, Kex, of the order of 0.01 to 90 for the metals (Fe
No Title by K. Böckenhoff; W. Fischer (pp. 670-674).
The main features of polyelectrolyte titrations with end-point indication by means of a particle-charge detector (PCD) were investigated. Because of their well-defined character, the charges of different synthetic polyelectrolytes and of latex samples with different functional groups were measured at different pH and ionic strength. The results show that PCD is a valuable tool for detecting effective or dissociated counterion charge without additional model assumptions. For negatively charged samples with exclusively strong acid functional groups, an excellent agreement was obtained between cation-exchange capacity and the charge measured by PCD over a wide pH range. For samples with additional carboxyl groups, the PCD charge was significantly lower than the total charge calculated from cation-exchange results. It can be concluded that counterion immobilization by a Stern layer-type arrangement is responsible for this effect.
No Title by Z. Filip; J. Berthelin (pp. 675-681).
Humic substances are usually the refractory part of natural organic matter, and in a landfill they can retain inorganic and organic micropollutants. This study has investigated analytically whether humic acids (HA) extracted by use of alkali from either fresh municipal refuse or from refuse disposed of in a landfill for up to 12 months can resist microbial degradation under aerobic conditions. When added as a supplementary nutrient source, up to 63.6% of HA was utilized and this percentage was enhanced to a mean value of 88.5% when different HA preparations were used as the sole source of carbon. In cultures of a soil microbial community containing the same preparations as sole sources of nitrogen, HA was usually completely utilized. The remaining HA re-isolated from some microbial cultures were highly depleted in carbon and, simultaneously, the nitrogen content was enhanced. The FTIR spectra were indicative of strong participation of aliphatic structural units in the refuse-related HA preparations. Because of the microbial activity, different carbonaceous substances were primarily removed from the HA structure, and an increase in nitrogenous molecular groups became apparent. The structural transformations brought about by soil microorganisms "in vitro" corresponded to those occurring naturally in HA obtained from refuse aged for 12 months in a landfill.
No Title by G. Abbt-Braun; J. Jahnel (pp. 682-687).
The sulfur compounds of refractory organic substances (ROS) of different origin have been characterized. Total organic sulfur was determined by elemental analysis. Sulfur-containing amino acids methionine and cystine were analyzed chromatographically after hydrolysis with HCl or by proteolytic digestion using enzymes.The results obtained from elemental analysis show that the total amount of sulfur is strongly dependent on the origin of the samples, because of different environmental factors during the formation of ROS. For naturally occurring samples isolated from soil seepage water, bog lake water and ground water the carbon-to-sulfur atomic ratios (C/S) decrease with the stage of humification, because of preferential loss of carbon. In humic acids (HA) isolated from secondary effluent the high value of the nitrogen-to-sulfur ratio (N/S) was indicative of a large amount of protein-derived nitrogen and sulfur compounds. In the solutions from acid hydrolysis the total amount of amino acid carbon related to the dissolved organic carbon (DOC) was generally less than 5%. Percentages of cystine related to all the amino acids detected were in the range 4 to 16%; methionine was below the detection limit for most samples. The results show that cystine is very important among the amino acids released. Enzymatic release generally resulted in smaller amounts of amino acids, indicating that these molecules are not only present in bioavailable protein-like structures.The data were compared with those from other approaches reported in the literature for the speciation of sulfur forms in ROS, including potentiometric titration, differential reduction methods, and spectroscopic investigations.