Heinz-Jürgen Brauch

Pharmaceuticals in groundwaters: Analytical methods and results of a monitoring program in Baden-Württemberg, Germany

In this paper, analytical methods for the trace-level determination of 60 pharmaceuticals in aqueous samples are presented. The list of compounds amenable to the methods comprises analgesics, antiphlogistics, antirheumatics, beta-blockers, broncholytics, lipid-lowering agents (or their metabolites), antiepileptics, vasodilators, tranquillizers, antineoplastic drugs, iodinated X-ray contrast media, and antibiotics of different kind, mainly sulfonamides, macrolides, and penicillins. All methods are based on automated solid-phase extraction followed by GC-MS (after derivatization of the acid compounds) or HPLC-electrospray ionization MS-MS. After an intense validation, which included the determination of performance data according to the German standard method DIN 32645 (limit of detection, limit of identification, limit of determination), the determination of linearity, recovery, and repeatability and the study of matrix effects, the analytical methods were applied within a monitoring program on the occurrence of pharmaceuticals in groundwaters of Baden-Württemberg. During this monitoring program, it was found that several of the compounds under investigation could be detected in groundwaters and their occurrence could be traced back to an impact of municipal or industrial waste water.

Analysis of primary and secondary aliphatic amines in waste water and surface water by gas chromatography-mass spectrometry after derivatization with 2,4-dinitrofluorobenzene or benzenesulfonyl chloride

Two methods for the determination of aliphatic amines such as methylamine, dimethylamine, ethylamine, diethylamine, piperidine, pyrrolidine or morpholine in waste water and surface water at the sub-ppb level are presented. The methods are based on a derivatization of the amines within the aqueous medium with 2,4-dinitrofluorobenzene and benzenesulfonyl chloride, respectively. In both cases the derivatives are extracted with dichloromethane and measured by GC-MS. The performance data of the two methods are compared and the method which is based on the derivatization with benzenesulfonyl chloride is finally applied to industrial waste waters and surface waters in order to determine the rate of occurrence of aliphatic amines in the aquatic environment.

Occurrence of the antidiabetic drug metformin in sewage and surface waters in Germany

The antidiabetic drug metformin is among the pharmaceuticals with the highest production numbers world-wide. This paper presents first data on the occurrence of metformin in sewage and surface waters in Germany. Analysis of metformin is based on pre-concentration of the analyte onto a polymeric solid-phase material and subsequent determination by liquid chromatography and tandem mass spectrometry. Applying the method to sewage and surface waters, recoveries >90% and limits of detection of 10 ng L(-1) could be achieved by pre-concentration of a sample volume of only 10 mL. Measurements in sewage and surface waters showed an almost ubiquitous presence of metformin in the aquatic environment. The measured concentration levels in sewage treatment plant influents correlate nicely to the prescription numbers for metformin in Germany. During sewage treatment a significant reduction of metformin concentrations was observed which seems to be mainly due to microbial degradation. Despite this significant elimination during sewage treatment, metformin was found in all river waters under investigation. Concentration levels depend on the sewage fraction of the receiving waters and for most rivers are in the range of several 100 ng L(-1), i.e. in the same order of magnitude or even higher than for other relevant pharmaceutical residues.

MTBE (methyl tertiary-butyl ether) in groundwaters: Monitoring results from Germany

In Germany information on the occurrence of MTBE in groundwaters is scarce. In order to assess the German situation, in 1999 a monitoring programme on MTBE in groundwater was set up. Within this survey 170 wells were examined, which are used as groundwater monitoring points or which are foreseen for drinking water extraction in emergency cases or for irrigation purposes. In rural areas MTBE was found only in 9% of all samples in concentrations above the limit of determination (LOD) of 0.05 microg L(-1). In urban areas MTBE was detected in 49% of all wells under investigation and the median concentration was calculated to 0.17 microg L(-1). In one case a maximum MTBE concentration of almost 700 microg L(-1) was detected. As a first result of this survey one can conclude, that MTBE is regularly present in German groundwaters under urban areas. Although investigations about the occurrence of MTBE in German groundwaters have to be extended in future, this first snapshot can lead to the assumption, that MTBE concentrations due to diffuse sources are lower than the ones found in the USA. Nevertheless, e.g. accidental spills can lead to elevated MTBE concentrations.

Determination of aromatic sulfonates in the river Elbe by on-line ion-pair extraction and ion-pair chromatography

An automated method based on ion-pair extraction and HPLC has been used to investigate the occurrence of aromatic sulfonates in the river Elbe. Twelve different naphthalene, anthraquinone and stilbene sulfonates have been found. The substances have been detected by UV detection at 220 nm and, if possible, by their fluorescence signal. The aromatic sulfonates have been identified by their retention time and by comparing their UV spectra with the respective spectra of reference substances. The occurrence of these substances in the river Elbe water is caused by a discharge of several waste water effluents. The results showed, that certain naphthalene sulfonates cannot be totally removed by biological treatment and adsorption on activated carbon.

Structural elucidation of main ozonation products of the artificial sweeteners cyclamate and acesulfame

PurposeThe two artificial sweeteners cyclamate (CYC) and acesulfame (ACE) have been detected in wastewater and drinking water treatment plants. As in both facilities ozonation might be applied, it is important to find out if undesired oxidation products (OPs) are formed.MethodsFor the separation and detection of the OPs, several analytical techniques, including nuclear magnetic resonance experiments, were applied. In order to distinguish between direct ozone reaction and a radical mechanism, experiments were carried out at different pH values with and without scavenging OH radicals. Kinetic experiments were used for confirmation that the OPs are formed during short ozone contact time applied in waterworks. Samples from a waterworks using bank filtrate as raw water were analyzed in order to prove that the identified OPs are formed in real and full-scale ozone applications.ResultsIn the case of CYC, oxidation mainly occurs at the carbon atom, where the sulfonamide moiety is bound to the cyclohexyl ring. Consequently, amidosulfonic acid and cyclohexanone are formed as main OPs of CYC. When ozone reacts at another carbon atom of the ring a keto moiety is introduced into the CYC molecule. Acetic acid and the product ACE OP170, an anionic compound with m/z=170 and an aldehyde hydrate moiety, were identified as the main OPs for ACE. The observed reaction products suggest an ozone reaction according to the Criegee mechanism due to the presence of a C=C double bond. ACE OP170 was also detected after the ozonation unit of a full-scale drinking water treatment plant which uses surface water-influenced bank filtrate as raw water.ConclusionsAcesulfame can be expected to be found in anthropogenic-influenced raw water used for drinking water production. However, when ACE OP170 is formed during ozonation, it is not expected to cause any problem for drinking water suppliers, because the primary findings suggest its removal in subsequent treatment steps, such as activated carbon filters.

Polar nitrogen compounds and their behaviour in the drinking water treatment process.

Aliphatic and alicyclic amines as well as ethanolamines are extremely polar compounds, frequently found in the environment, and some of them have high toxicity. To address the contamination of selected German surface waters examined and the importance of bank filtration in Eastern Germany, investigations on the behaviour of polar organic nitrogen compounds during water treatment were carried out. Test conditions were designed appropriately for drinking water treatment conditions, and the tests were carried out using model water as well as bank filtrate. Test filter studies of microbial degradation of selected compounds demonstrated the following order of biodegradability: ethanolamine > dimethylamine > pyrrolidine > ethylenediamine. piperidine > diethylamine > morpholine > piperazine > cyclohexylamine. Flocculation tests using iron salts as well as aluminium salts as coagulants showed very low removal rates for the amines. The best results for the removal of the polar organic nitrogen compounds from the water were obtained using ozonation. Based on the reaction-rate constants, the order of degradation by ozone is: piperazine > morpholine > ethylenediamine > piperidine, cyclohexylamine > dimethylamine > ethanolamine > pyrrolidine > diethylamine. Disinfection by chlorine-containing agents under drinking water treatment conditions did not give effective elimination of the selected polar nitrogen compounds.

Pesticides and other organic micro pollutants in the river Elbe

The main components of organic micro pollution regularly found in the river Elbe, belong to the wide spectrum of pesticides, nitro and chloro benzenes and the chelating agents, especially ethylenediaminetetraacetic acid (EDTA). The level of organic micro pollution with pesticides and the other organic micro pollutants in the upper and middle reaches of the river Elbe between Schmilka and Wittenberge was determined over a period of nearly three years. Four sample preparation methods (SPE: solidphase extraction and LLE: liquid-liquid extraction both with and without derivatization) have been used to analyze a wide spectrum of pesticides with different polarities by GC/ECD, NPD and MS. The pesticide pollution caused by the triazines decreases significantly from 0.35 μg/l (mean value) in 1992 up to 0.15 μg/l (mean value) in 1994. The correlation with the river water flow shows the diffuse character of the triazine input. In the last year of the pesticide screening a change to the more polar substances such as phenoxyalkanoic acid and nitrophenol pesticides as well as chloralkanoic acid pesticides have been noticed. The origin of trichloroacetic acid (TCA) can be explained by the waste influence, supported by the good correlation of the TCA course with the chloroform concentrations determined.

Transformation of the artificial sweetener acesulfame by UV light.

The transformation of the artificial sweetener acesulfame by direct photolysis was investigated at various pH values, in different water types and at various concentration levels. Main photodegradation products of acesulfame were elucidated and analyzed both in laboratory experiments and in a full-scale waterworks using UV treatment for disinfection purposes. The degradation of acesulfame was found to be independent of the pH (range 5-11) and followed pseudo first order kinetics in a concentration range between 1 μg∙L(-1) and 10 mg∙L(-1). Calculated rate constants were in the range between 5.4·10(-3)s(-1) and 7.4·10(-3)s(-1). The main photodegradation products of acesulfame were separated by ion exchange chromatography and high performance liquid chromatography and were identified as hydroxylated acesulfame and iso-acesulfame by high resolution mass spectrometry and fragmentation experiments. In the case of iso-acesulfame an intramolecular rearrangement is assumed as the transformation product has a higher polarity and different product ions after MS fragmentation compared to acesulfame. Minor transformation products were identified as amidosulfonic acid and sulfate by comparison with analytical standards. The transformation pathway was found to be transferable to drinking water production as the identified transformation products were also detected to a similar extent in fortified tap water. In a Swiss full-scale waterworks acesulfame concentrations were reduced by approximately 30% and one of the main UV transformation products could be qualitatively detected.

Polyfluorinated chemicals in European surface waters, ground- and drinking waters

Polyfluorinated chemicals (PFCs), especially short chain fluorinated alkyl sulfonates and carboxylates, are ubiquitously found in the environment. This chapter aims at giving an overview of PFC concentrations found in European surface, ground- and drinking waters and their behavior during conventional water treatment steps. Main PFC sources to the aquatic environment are municipal and industrial wastewater treatment plants. Treated landfill leachates also showed to be an important source of PFCs to surface waters. Existing data suggest central and south European rivers to have higher concentrations and mass discharges of PFCs than Northern European countries. However, this conclusion might be an artifact due to differences of monitoring activities in different regions. High PFC levels in groundwater are often restricted to some contaminated areas, e.g., due to illegal waste deposition on agricultural land or in the vicinity of a fluoropolymer producing factory. Sites with former fire-fighting activities are also potential “hot spot” areas. Concentrations encountered in drinking water remain fairly low on average. Typical concentrations are in the low ng/L range with the exception of highly contaminated areas, like in the Mohne and Ruhr area in Germany. The encountered concentrations in drinking water depend on the treatment technologies used to purify the water. Drinking water prepared with activated carbon or reverse osmosis will in general contain lower concentrations in tap water than in the raw water. However, the efficiency of water treatment depends much on the local boundary conditions.