T. J. Gremm

Pharmaceutical Residues in the Aquatic Environment and their Significance for Drinking Water Production

Pharmaceuticals belong to the environmentally relevant compounds. They are produced and administered for human and animal medical care. Due to the amount and types of applications pharmaceuticals can reach the environment, in particular the aquatic systems. Being produced and applied with the aim of causing a biological effect, their occurrence in the environment is of ecotoxicological interest. In particular this is of importance for antibiotics, but also for antineoplastics, hormones (compounds with endocrinic effects) and various compounds and metabolites that have already been detected in sewage plant effluents and surface waters in considerable concentrations (e.g. bezafibrate, clofibric acid, ibuprofen) (Stumpf et al. 1999; Hirsch et al. 1999). In particular, clofibric acid — a therapeutically active metabolite of clofibrate ethyl, etofibrate and ethofyllinclofibrate — shows a highly persistent behaviour in the aquatic environment and was already found in ground and drinking water in the city of Berlin (Heberer et al. 1998; Heberer and Stan 1996) as well as in the North Sea (Buser et al. 1998).

Determination of organotin compounds in aqueous samples by means of HPGC-AED

Abstract Organotin compounds belong to the widespread micropollutants in the aquatic environment. They can be analysed by different analytical procedures. The recently available atomic emission detector (AED) in combination with gas chromatography is a promising tool for this task. Identification and quantification of organotin compounds in water and sediment can be achieved in ranges of ng/l and μg/l, respectively. The quality criteria for the values obtained depend strongly on the matrices and on the tin-species investigated. In general recovery rates are higher for aqueous samples than for sediments. From model experiments it can be deduced that humic substances play an important role in adsorption of tin organyles in sediment. In addition to the known fact that activated carbon readily eliminates tributyltin from aqueous solutions, the kinetics of recovery experiments show that part of the organotin compounds are irreversibly adsorbed on solid phase.

Application of liquid chromatography-particle beam mass spectrometry and gas chromatography-mass spectrometry for the identification of metabolites of polycyclic aromatic hydrocarbons

SummaryTwo liquid chromatography-particle beam mass spectrometry (LC-PBMS) systems have been used for analysis of polycyclic aromatic hydrocarbon metabolites in water samples from a biological decomposition model experiment. The results were compared with those obtained by classical gas chromatography-mass spectrometry. Evaluation of spectral data indicated the presence of six main metabolites; 1H,3H-naphtho [1,8-cd]pyran-1,3-dione, 1-(hydroxymethyl)naphthalene, and 1,2-acenaphthenedione were identified by use of standard substances and spiking experiments. Enrichment of the investigated water samples with online pre-column (C18) concentration, freeze-drying, and solvent extraction led to similar results with only slight differences. The application of microbore separation columns proved to be a promising tool in particle beam LC-MS measurements.

The importance of element speciation in water analysis — a plea for further investigations

Water analysis is dominated by parameters given in laws and recommendations concerning water quality. Speciation has been broadly neglected. This might be due to the difficulties in defining speciation and in determining species at low concentrations. This paper addresses the physical, chemical and biological approaches to speciation and gives examples for methods which are suited for species determination in aquatic systems. Metals and non-metallic elements are covered as well. It is obvious that speciation is a key for understanding the function of aquatic ecosystems and their technical utilization.

Use of the anion-exchange resin amberlite IRA-93 for the separation of arsenite and arsenate in aqueous samples.

The method described uses the separation of As(III) and As(V) species in aqueous samples by means of the anion-exchange resin Amberlite IRA-93. The samples were acidified using acetic acid and passed through a glass column filled with pre-treated Amberlite IRA-93 resin. As(III) was poorly adsorbed on the anionic exchanger material, whereas As(V) was retained. The arsenic concentration was measured in the column effluent by graphite furnace AAS (GF-AAS). The retained As(V) was eluted from the column using 1 M NaOH. Prior to the determination of the As(V) concentration in the NaOH eluate, the eluate was passed through a glass column filled with a cation-exchange resin (Amberlite 200) to remove sodium ions and minimize the Na + interference with the AAS determination. After calibration the method was applied to the separation ofAs(III) and As(V) species in two aqueous extracts of arsenic contaminated soils. The results were compared with those obtained from an on-line separation and determination of As(III) and As(V) in the aqueous soil extracts using a state of the art HPLC-ICP-MS system.

Liquid chromatographic characterization of refractory organic acids

Abstract Liquid chromatography (LC) in the high and medium pressure mode in association with sensitive detection systems [UV-vis, diode array detector (DAD), fluorescence, dissolved organic carbon (DOC)] is used for the characterization of dissolved organic matter in aqueous samples. Even though the chromatographic mechanisms for the fractionation of humic-type organic substances are not fully known, the use of different columns (gel, C-18 phases, etc.) adds significantly to the understanding of the functionality of the organics. The chromatograms show that there are larger differences between the isolated fulvic acids (FAs) and the organics in unaltered water samples than between FAs from different origin but isolated using the same method. The influence of the isolation procedure is demonstrated on soil extracts. For the first time an on-line DOC detection system is used to trace the liquid chromatogram of a tap water sample.

Reduction of matrix-effects in pesticide analysis with gas chromatography-ion trap mass spectrometry (GC/ITD-MS) by clean-up processes

In this work analytical determination of some pesticides frequently used in Morocco and Turkey was carried out with solid-phase extraction (SPE) and gas chromatography-ion trap mass spectrometry (GC/ITD-MS). Because of coextracts from the SPE material and/or water sample, recovery values beyond 100 % for some of the selected analytes were observed. This enhanced signal intensity was explained by an enhanced ionisation that is introduced by coeluting sample matrix. A clean-up method using florisil was tested for the removal of matrix substances. The removal of coextracts in the sample after forisil clean-up was proved by a standard addition method. Probenaufbereitungsschritte zur Verminderung von Matrixeffekten bei der Pestizidanalytik mittels Gaschromatographie-Ion-Trap-Massenspektrometrie (GC/ITD-MS) In der vorliegenden Arbeit wurde die analytische Bestimmung einiger in Marokko und der Turkei haufig verwendeter Pestizide mittels Gaschromatographie-Ion-Trap-Massenspektrometrie (GC/ITD-MS) nach vorhergehender Festphasenextraktion (SPE) vorgenommen. Aufgrund von Co-Extrakten aus dem Festphasenmaterial und/oder der Wasserprobe wurde fur einige der Analyten eine Wiederfindung von uber 100 % beobachtet. Die verstarkte Signalintensitat wird auf die zusatzliche Ionisierung co-eluierender Matrixbestandteile zuruckgefuhrt. Durch einen Vorreinigungsschritt mit Florisil liesen sich die Matrixbestandteile entfernen, was mit Hilfe der Standardadditionsmethode gezeigt wurde.

Problems and solutions in pesticide analysis using solid-phase extraction (SPE) and gas chromatography ion-trap mass spectrometry detection (GC-MS)

In the present study an analytical method was tested for the determination of selected pesticides and metabolites using solid-phase extraction (SPE) and gas chromatography ion-trap mass spectrometry (GC-MS). The extraction efficiency of C18, Isolut ENV+, and Lichrolut EN for SPE was compared for trifluralin, fenitrothion, endosulfan, propargite, 2,4-D, 3-methyl-4-nitrophenol, 2-(4-tert-butylphenoxy)cyclohexanol, endosulfan sulfate, and 2,4-dichlorophenol. Isolut ENV+ and C18 showed good results as sorbents and acetone as an elution solvent for SPE for the selected pesticides. Recoveries varied between 36% and 176% with a relative standard deviation of 2...18%. Because of coextracts from the SPE materials, recovery values higher than 100% were obtained for fenitrothion, endosulfan sulfate, and 2,4-D with C18 as well as for endosulfan sulfate and 3-methyl-4-nitrophenol with Isolut ENV+. A standard addition method was used to verify the occurrence of coextracts in the sample after SPE. Probleme und Losungen bei der Pestizidanalyse mittels Festphasenextraktion (SPE) und Gaschromatographie-Ion-Trap-Massenspektrometrie (GC-MS) In der vorliegenden Arbeit wurde eine analytische Methode zur Bestimmung von ausgewahlten Pestiziden und ihrer Metaboliten mittels Festphasenextraktion (SPE) und Gaschromatographie-Ion-Trap-Massenspektrometrie (GC-MS) getestet. Die Extraktionseffizienz der Festphasen C18, Isolut ENV+ und Lichrolut EN wurde fur Trifluralin, Fenitrothion, Endosulfan, Propargite, 2,4-D, 3-Methyl-4-nitrophenol, 2-(4-tert-Butylphenoxy)cyclohexanol, Endosulfansulfat und 2,4-Dichlorphenol verglichen. Isolut ENV+ und C18 zeigten gute Ergebnisse als Sorbentien mit Aceton als Elutionsmittel fur die SPE der ausgewahlten Pestizide. Die Wiederfindungsraten lagen zwischen 36% und 176% mit Standardabweichungen von 2...18%. Durch Matrixeffekte wurden Wiederfindungswerte uber 100% fur Fenitrothion, Endosulfansulfat und 2,4-D mit C18 und fur Endosulfansulfat und 3-Methyl-4-nitrophenol mit Isolut ENV+ erhalten. Eine Standardadditionsmethode wurde angewandt, um nach der SPE die Matrixeffekte in der Probe zu prufen.

Zielvorgaben für Pflanzenschutzmittelwirkstoffe und andere Schadstoffe in Oberflächengewässern

In der vorliegenden Arbeit wurden fur ausgewahlte gefahrliche Stoffe Vorschlage fur Zielvorgaben zum Schutz der aquatischen Lebensgemeinschaften erarbeitet. Die vorgeschlagenen Zielvorgaben wurden auf der Grundlage der Leitlinien zur Ableitung von Zielvorgaben der Internationalen Kommission zum Schutze des Rheins (IKSR) ermittelt. Zur Ableitung einer Zielvorgabe sollten im Regelfall okotoxikologische Untersuchungen aus vier Trophiestufen der Gewasserbiozonose mit den typischen Vertretern Bakterien, Algen, Kleinkrebse und Fische herangezogen werden. Die Wirkungsdaten wurden in Zusammenarbeit mit dem Umweltbundesamt (UBA) okotoxikologischen Datenbanken entnommen. Um der Unsicherheit der Ubertragung der an wenigen Organismenarten gewonnenen Laborergebnisse auf reale Gewasserverhaltnisse Rechnung zu tragen, wurde das niedrigste akute bzw. langerfristige Testergebnis fur die empfindlichste Art mit einem Ausgleichsfaktor multipliziert. Fur sieben Pestizide wurden Zielvorgaben vorgeschlagen, die unterhalb einer Konzentration von 0.1 μg/L liegen. Demnach sind die okotoxikologisch basierten Vorgaben noch strenger als der nach der Trinkwasserverordnung vorgesehene generelle Grenzwert fur Pestizide von 0.1 μg/L. Andererseits wurden fur die uberwiegende Anzahl der betrachteten Stoffe hohere Werte abgeleitet. Die grose Spannbreite der Werte fur die Zielvorgaben zeigt sehr deutlich, dass gerade bei der Stoffgruppe der Pestizide keine einheitliche Konzentration als Qualitatsanforderung fur Gewasser genannt werden kann, sondern dass die einzelnen Pestizide sehr unterschiedliche Wirkungen auf die Gewasserbiozonose zeigen. Quality Targets for Pesticides and Other Pollutants in Surface Waters Surface waters are not only adversely affected by industrial and municipal wastewaters but also by diffuse sources. For the control of the ecological water quality, so-called quality targets are set. The quality targets are threshold concentrations for hazardous substances related to the protected goods like water ecosystems, drinking water supply, sediments, or fishing. In this paper, quality targets for the protection of aquatic life in surface waters were derived on the basis of a concept developed by the International Commission for the Protection of the Rhine (Internationale Kommission zum Schutze des Rheins – IKSR). The quality targets for the selected hazardous substances, which mainly belong to the chemical class of pesticides, were calculated using ecotoxicological results for species of bacteria, algae, fish, and small crustaceans, as the four trophic standards of the water ecosystem. In cooperation with the Federal Environmental Agency (Umweltbundesamt – UBA) the effect data were taken from ecotoxicological data bases. According to the concept of the IKSR, the lowest test result for the most sensitive species was multiplied by an assessment factor. This proceeding concerns the difficulty in describing the complex interactions in water ecosystems with toxicity data of single laboratory experiments for a few organisms. For seven pesticides quality targets below 0.1 μg/L were proposed. These results show that the ecotoxicologically based quality targets might be even lower than the limit values for pesticides in drinking water of 0.1 μg/L. But for most of the substances the determined values are significantly higher. The great concentration range of quality targets demonstrates distinctly that one standard concentration for all pesticides could not be given with regard to the different effects on aquatic organisms.

Qualität russischer Flüsse: Die große Unbekannte

Die Wasserqualitatsuberwachung in Russland ist aufgrund einer fehlenden finanziellen Basis in einem so kritischen Zustand, dass die wenigen noch ermittelten Messdaten in vielen Fallen hinsichtlich ihrer Qualitat und Aussagekraft fraglich erscheinen. 1996 begann ein deutsch-russisches Forschungsprojekt zur Untersuchung der Wasserqualitat in den Flussen Moskva Oka und Wolga. Die wesentlichen Schadstoffe in der Moskva und Oka sind Nahrstoffe, AOX und polycyclische aromatische Kohlenwasserstoffe (PAK). Die Moskva ist als Vorfluter der Region Moskau sehr stark verschmutzt. Die Hauptquelle der Belastung ist unzureichend geklartes kommunales Abwasser. Erste Ergebnisse aus der Wolgaforschung ergaben einen uberraschend guten Zustand des Gewassers im Untersuchungsgebiet von Nishny Novgorod. Due to financial problems, water quality assessment in Russia has deteriorated to a level characterized by questionable quality and meaning. In 1996, a German-Russian research project was started with the aim to investigate systematically the water quality of the rivers Moskva, Oka and Wolga. The dominating pollutants in the rivers Moskva and Oka are eutrofying substances, TOX and polycyclic aromatic hydrocarbons (PAHs). The river Moskva receives the effluents of the whole Moskva region and is hence heavily polluted.The main source is the poorly treated municipal waste water. First results of the river Wolga in the region of Nishnij Novgorod show a surprisingly good water quality.