Wolfram Baumann

Bio: Wolfram Baumann is an academic researcher from University of Mainz. The author has contributed to research in topics: Dipole & Excited state. The author has an hindex of 23, co-authored 80 publications receiving 2362 citations.

Polar drug residues in sewage and natural waters in the state of Rio de Janeiro, Brazil

Abstract: The drug residues of lipid regulators, anti-inflammatories and some drug metabolites have been detected in raw sewage, treated waste water and river water in the state of Rio de Janeiro, Brazil. These residues are mainly derived from humans via excretion. The median concentrations in the effluents of sewage treatment plants (STPs) of most drugs investigated in this study ranged from 0.1 to 1 μg/l. The removal rates of individual drugs during passage through a Brazilian STP varied from 12 to 90%. As a consequence of the incomplete removal of these residues during passage through a STP, rivers were also found to be contaminated. Median concentrations ranged from between 0.02 and 0.04 μg/l in river water, whereas the maximum values were observed to be up to 0.5 μg/l.

Nachweis von Arzneimittelrückständen in Kläranlagen und Fliessgewässern

Abstract: An analytical method for the simultaneous determination of residues from pharmaceutical compounds in water samples by GC/MS was developed Those compounds were lipid regulating agents (Gemfibrozil, Bezafibrate), active metabolites of lipid regulating agents (Clofibric acid, Fenofibric acid), antirheumatics (Diclofenac, Ibuprofen, Ketoprofen, Fenoprofen, Indometacine) and analgetics (acetyl salicylic acid) The method was used for the examination of waste water and effluents of sewage plants, of river and tap water It was shown that nearly all investigated substances occur in the effluents of the sewage plants The highest concentration determined in an effluent was 456 μg/l (Bezafibrate) In consequence of the incomplete elimination in sewage plants, the pharmaceutics were also detected in river water Their concentrations were in the range up to 049 μg/l (Diclofenac) Pharmaceutics could be detected even in tap water : Clofibric acid (up to 70 ng/l), and sporadically Bezafibrate (up to 27 ng/l), Diclofenac (1 to 6 ngA) and Ibuprofen (1 to 3 ng/l) This investigation shows that the examined pharmaceutical compounds and metabolites have to be seen as new ubiquitarily distributed chemicals in the environment

Considerations on the dipole moment of molecules forming the twisted intramolecular charge transfer state

Abstract: Several derivatives of dual-fluorescing dimethylaminobenzonitrile (DMABN) are compared regarding their ground and excited-state dipole moments extracted from electro-optical emission and solvatochromic measurements. The comparison includes bridged model compounds as well as compounds with different degrees of steric hindrance to planarity, as well as ester and carbazolyl derivatives. The results are discussed on the basis of the twisted intramolecular charge transfer (TICT) model, the most widely accepted model. They show that (i) the dipole moment of the A (TICT) state (long-wavelength band) shows only little solvent sensitivity (polarizability), (ii) this observed small dependence of the dipole moment on solvent polarity can be considered as the result of overlap of two fluorescence bands or of solvent-induced changes in the mean deviation from the ideal TICT geometry (“atomic polarizability”), (iii) the dipole moment of the B state (short-wavelength band) is considerably smaller than that of the A band, (iv) the order of the dipole moment values obtained from solvatochromy is the same as from theoretical calculations: μgp <μep (1Lb) <μep(1La) <μeT, (v) ester derivatives show a reduced dipole moment with respect to the corresponding nitriles and (vi) sterically crowded compounds seem to possess a reduced dipole moment. The possible reasons are discussed. The agreement and the differences between the two methods are discussed and compared with results from dielectric loss measurements and from quantum-chemical calculations.

Nachweis von natürlichen und synthetischen Östrogenen in Kläranlagen und Fliessgewässern

Abstract: A method for trace analysis of steroids in water with lower limits of detection down to I ng/l was developed. Using this method natural and synthetic estrogen as well as the phytoestrogen β-sitosterol can be detected even in water samples which are extremely contaminated by organic matter. The occurrance of steroids in influents and effluents of sewage plants, river water and tap water was investigated. It was shown that the steroids are eliminated effectively but not completely in sewage plants (58 to 91 %). In effluents of different sewage plants, estradiol (up to 20 ng/l), mestranol (up to 21 ng/l), ethinyl estradiol (up to 62 ng/l) and β-sitosterol (up to 402 ng/l) were detected. In river water the synthetic estrogens mestranol and ethinyl estradiol were occasionally detected with concentrations below 5 ng/l. β-sitosterol was determined in river water in a concentration range up to 56 ng/l. The investigated natural and synthetic estrogens were not found in tap water. Only the phytoestrogen β-sitosterol was detectable in some samples with concentrations in the range from 20 to 60 ng/l.

UV-Filtersubstanzen in Wasser und Fischen

Abstract: Zur Erfassung der UV-Filtersubstanzen wird eine Methode vorgestellt, die die simultane Bestimmung dieser Verbindungen und von Organochlorverbindungen wie PCB und DDT in unterschiedlichen Fischkompartimenten bis in den ng/kg-Bereich ermoglicht. Die Nachweisgrenzen liegen zwischen 40 und 90 ng/kg Filet und die Wiederfindungsraten bewegen sich zwischen 78 und 104%. Die Belastung von Wasser und Fischen des Meerfelder Maares, Eifel, mit UV-Filtersubstanzen wurde 1991 und 1993 exemplarisch untersucht. Insgesamt konnten in den Fischen des Meerfelder Maares 6 UV-Filtersubstanzen identifiziert und quantifiziert werden. Die im Sommer 1991 gefangenen Barsche waren mit 2,0 mg/kg Fett (Summe nachgewiesener UV-Filtersubstanzen) und die Rotaugen von 1993 mit 0,50 mg/kg Fett belastet. In beiden Fischarten lag die Belastung in der gleichen Grosenordnung wie die der Organochlorverbindungen PCB und DDT. In den Rotaugen aus drei weiteren deutschen Seen konnte im Filet Methylbenzylidencampher, eine lipophile UV-Filtersubstanz, nachgewiesen werden. Diese Befunde zeigen, das UV-Filtersubstanzen in deutschen Seen weir verbreitet und vermutlich als relevante Umweltchemikalien zu betrachten sind. Da im Wasser der Seen die Konzentrationen der UV-Filter substanzen meistens unter der Bestimmungsgrenze lagen, konnen Fische fur diese lipophilen Verbindungen als Expositionsmonitor verwendet werden. Eine okotoxikologische Bewertung ist zum jetzigen Zeitpunkt nicht moglich, da die Datenlage vollig unzureichend ist.

Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: a national reconnaissance.

Abstract: To provide the first nationwide reconnaissance of the occurrence of pharmaceuticals, hormones, and other organic wastewater contaminants (OWCs) in water resources, the U.S. Geological Survey used five newly developed analytical methods to measure concentrations of 95 OWCs in water samples from a network of 139 streams across 30 states during 1999 and 2000. The selection of sampling sites was biased toward streams susceptible to contamination (i.e. downstream of intense urbanization and livestock production). OWCs were prevalent during this study, being found in 80% of the streams sampled. The compounds detected represent a wide range of residential, industrial, and agricultural origins and uses with 82 of the 95 OWCs being found during this study. The most frequently detected compounds were coprostanol (fecal steroid), cholesterol (plant and animal steroid), N,N-diethyltoluamide (insect repellant), caffeine (stimulant), triclosan (antimicrobial disinfectant), tri(2-chloroethyl)phosphate (fire retardant), and 4-nonylphenol (nonionic detergent metabolite). Measured concentrations for this study were generally low and rarely exceeded drinking-water guidelines, drinking-water health advisories, or aquatic-life criteria. Many compounds, however, do not have such guidelines established. The detection of multiple OWCs was common for this study, with a median of seven and as many as 38 OWCs being found in a given water sample. Little is known about the potential interactive effects (such as synergistic or antagonistic toxicity) that may occur from complex mixtures of OWCs in the environment. In addition, results of this study demonstrate the importance of obtaining data on metabolites to fully understand not only the fate and transport of OWCs in the hydrologic system but also their ultimate overall effect on human health and the environment.

Pharmaceuticals and personal care products in the environment: agents of subtle change?

Abstract: During the last three decades, the impact of chemical pollution has focused almost exclusively on the conventional "priority" pollutants, especially those acutely toxic/carcinogenic pesticides and industrial intermediates displaying persistence in the environment. This spectrum of chemicals, however, is only one piece of the larger puzzle in "holistic" risk assessment. Another diverse group of bioactive chemicals receiving comparatively little attention as potential environmental pollutants includes the pharmaceuticals and active ingredients in personal care products (in this review collectively termed PPCPs), both human and veterinary, including not just prescription drugs and biologics, but also diagnostic agents, "nutraceuticals," fragrances, sun-screen agents, and numerous others. These compounds and their bioactive metabolites can be continually introduced to the aquatic environment as complex mixtures via a number of routes but primarily by both untreated and treated sewage. Aquatic pollution is particularly troublesome because aquatic organisms are captive to continual life-cycle, multigenerational exposure. The possibility for continual but undetectable or unnoticed effects on aquatic organisms is particularly worrisome because effects could accumulate so slowly that major change goes undetected until the cumulative level of these effects finally cascades to irreversible change--change that would otherwise be attributed to natural adaptation or ecologic succession. As opposed to the conventional, persistent priority pollutants, PPCPs need not be persistent if they are continually introduced to surface waters, even at low parts-per-trillion/parts-per-billion concentrations (ng-microg/L). Even though some PPCPs are extremely persistent and introduced to the environment in very high quantities and perhaps have already gained ubiquity worldwide, others could act as if they were persistent, simply because their continual infusion into the aquatic environment serves to sustain perpetual life-cycle exposures for aquatic organisms. This review attempts to synthesize the literature on environmental origin, distribution/occurrence, and effects and to catalyze a more focused discussion in the environmental science community.

Occurrence, fate and effects of pharmaceutical substances in the environment- A review

Abstract: Medical substances (pharmaceuticals) are a group of substances that until recently have been exposed to the environment with very little attention. The reason why they may be interesting as environmental micropollutants, is that medical substances are developed with the intention of performing a biological effect. Especially antibiotics used as growth promoters, as feed additives in fish farms are anticipated to end up in the environment. Very little is known about the exposure routes of the medical substances to the environment. Only few investigations have reported findings of medical substances in other field samples than sediment or treated waste water samples. Several substances seem to be persistent in the environment. This paper outlines the different anticipated exposure routes to the environment, summarises the legislation on the subject and gives an outline of present knowledge of occurrence, fate and effect on both the aquatic and terrestrial environments of medical substances. Present knowledge does not reveal if regular therapeutic use may be the source of a substance carried by sewage effluent into the aquatic system, even though clofibrate, a lipid lowering agent, has been identified in ground and tap water samples from Berlin. Further research would be necessary to assess the environmental risk involved in exposing medical substances and metabolites to the environment.

Occurrence of drugs in German sewage treatment plants and rivers

Abstract: The occurrence of 32 drug residues belonging to different medicinal classes like antiphlogistics, lipid regulators, psychiatric drugs, antiepileptic drugs, betablockers and β 2 -sympathomimetics as well as five metabolites has been investigated in German municipal sewage treatment plant (STP) discharges, river and stream waters. Due to the incomplete removal of drug residues during passage through a STP, above 80% of the selected drugs were detectable in at least one municipal STP effluent with concentration levels up to 6.3 μ g l −1 (carbamazepine) and thus resulting in the contamination of the receiving waters. 20 different drugs and 4 corresponding metabolites were measured in river and stream waters. Mainly acidic drugs like the lipid regulators bezafibrate, gemfibrozil, the antiphlogistics diclofenac, ibuprofen, indometacine, naproxen, phenazone and the metabolites clofibric acid, fenofibric acid and salicylic acid as well as neutral or weak basic drugs like the betablockers metoprolol, propranolol and the antiepileptic drug carbamazepine were found to be ubiquitously present in the riversand streams, mostly in the ng l −1 -range. However, maximum concentrations were determined up to 3.1 μ g l −1 and median values as high as 0.35 μ g l −1 (both bezafibrate). The drugs detected in the environment were predominantly applied in human medicine. It can therefore be assumed that the load of municipal STP effluents in the surface water highly influences the contamination. Due to their wide-spread presence in the aquatic environment many of these drugs have to be classified as relevant environmental chemicals.

Structural Changes Accompanying Intramolecular Electron Transfer: Focus on Twisted Intramolecular Charge-Transfer States and Structures

Abstract: 6. Rehybridization of the Acceptor (RICT) 3908 7. Planarization of the Molecule (PICT) 3909 III. Fluorescence Spectroscopy 3909 A. Solvent Effects and the Model Compounds 3909 1. Solvent Effects on the Spectra 3909 2. Steric Effects and Model Compounds 3911 3. Bandwidths 3913 4. Isoemissive Points 3914 B. Dipole Moments 3915 C. Radiative Rates and Transition Moments 3916 1. Quantum Yields and Radiationless Deactivation Processes 3916