Horst Fr. Schröder

Determination of fluorinated surfactants and their metabolites in sewage sludge samples by liquid chromatography with mass spectrometry and tandem mass spectrometry after pressurised liquid extraction and separation on fluorine-modified reversed-phase sorbents.

An analytical method was elaborated for simultaneous extraction and determination of fluorinated anionic and non-ionic surfactants in sewage sludge. Surfactant compounds were determined by liquid chromatography-mass spectrometry (LC-MS) after Soxhlet extraction, hot steam extraction and pressurised liquid extraction (PLE) using spiked sludge samples. PLE in a multiple-step procedure consisting of sequential use of ethyl acetate-dimethylformamide and methanol-phosphoric acid resulted in the most efficient extraction procedure. Quantitative analyses of the fluorinated anionic perfluorooctanesulfonate (PFOS) and the partly fluorinated non-ionic alkylpolyglycol ether (FAEO) surfactants were performed by selected ion monitoring LC-MS. Electrospray ionisation or atmospheric pressure chemical ionisation in negative or positive mode was performed. Recoveries between 105 and 120% could be reached. No PFOS and non-ionic FAEO surfactants in concentrations higher than 6 or 10 mg kg(-1) dry matter were observed in real environmental samples. Therefore aerobic and anaerobic biodegradation was performed to investigate the fate of fluorinated surfactants reaching wastewaters. Biological wastewater treatment in laboratory scale under aerobic or anaerobic conditions led to an elimination by biodegradation.

Tracing of surfactants in the biological wastewater treatment process and the identification of their metabolites by flow injection-mass spectrometry and liquid chromatography-mass spectrometry and -tandem mass spectrometry.

Results of aerobic biodegradation of alkyl ethoxylates (AEOs), of nonylphenol polyethoxylates (NPEOs), and of NPEO derivatives (sulfonates and sulfates), as well as anaerobic NPEO biodegradation monitored by flow injection analysis (FIA) or liquid chromatographic separation (LC) in combination with mass (MS) and tandem mass spectrometry (MS-MS) are presented. The application of visual pattern recognition in the FIA-MS mode showed quite different degradation pathways for C13-AEOs, so that aldehyde compounds as metabolites could be confirmed by collision-induced dissociation for the first time. Methyl ethers of AEO compounds were found to be persistent under aerobic conditions, while NPEO degradation resulted in nonylphenol polyether carboxylates. FIA- and LC-MS proved that NPEO derivatives used as anionic surfactants were either non-biodegradable (nonylphenol diethoxy sulfonate) or were primarily degraded (nonylphenol polyethoxy sulfates) into compounds of the same molar masses yet of different retention behaviour. Anaerobic degradation of NPEOs led to the generation of nonylphenols, which was confirmed by GC-MS.

Pollutants in drinking water and waste water

Extracts of drinking water and effluents from municipal and industrial sewage treatment plants were analysed by gas chromatography-mass spectrometry and by high-performance liquid chromatography combined with ultraviolet and/or mass spectrometric detection. After column chromatography or flow-injection analysis bypassing the analytical column, ionization was performed by a thermospray interface. Identification of the pollutants was carried out by tandem mass spectrometry, generating daughter-ion spectra by collision-induced dissociation. Most pollutants in drinking water and in the effluents of waste water treatment plants are surface-active compounds of anthropogenic origin or their biochemical degradation products. Difficulties encountered during separation, detection and identification are presented and discussed and techniques for solving these problems are proposed.

Analysis of polar organic pollutants in the Elbe river by flow injection analysis and high-performance liquid chromatography with tandem mass spectrometry.

Water extracts from the Elbe river and from one of its tributaries have been analyzed by gas chromatography-mass spectrometry (GC-MS) and by high-performance liquid chromatography combined with ultraviolet (UV) and/or MS detection. After column chromatography or flow injection analysis (FIA) bypassing the analytical column, ionization for MS was performed by either atmospheric pressure chemical ionization or electrospray. Since the reduction of the pollutant concentrations relative to the concentration of matrix components in the water samples had continued compared to earlier investigations [H.Fr. Schröder, J. Chromatogr. A 712 (1995) 123-140], substance-group-specific methods were applied for the screening for certain compound groups. For this purpose tandem mass spectrometry (MS-MS) was used to characterize the substance groups, with the help of parent-ion and neutral-loss scans. Identification then followed by means of daughter-ion spectra, which were generated by collisionally induced dissociation (CID) using FIA-MS-MS. The limitations of mixture analysis in the case of isomeric compounds present in the extracts are demonstrated.

Identification of degradation products of erythromycin a arising from ozone and advanced oxidation process treatment.

The degradation products of the macrolide antibiotic erythromycin A (ERY) arising from direct ozone attack and hydroxyl radical attack are presented for the first time. Ozone treatment was carried out by spiking ozone stock solutions to solutions containing ERY-ERY:O3 = 1:5 and 1:10 (M:M), while, in parallel, t-BuOH was used as a hydroxyl radical (*OH) scavenger. The advanced oxidation processes (AOPs) O3/UV, O3/H2O2, and UV/H2O2 were carried out to recognize and verify possible differences between their primary degradation products; the initial concentrations were ERY:O3 = 1:5 (M:M), ERY:O3:H202 = 1:5:5 (M:M:M), or ERY:H202 = 1:5 (M:M), respectively. Six degradation products were identified from ozonation-one originates from direct ozone attack on the tertiary amine group, while the others arise from radical ion attack, which might be formed during degradation of O3 in water. Fewer primary degradation products were observed arising from *OH-based treatments (AOP) than from ozonation, possibly because the reaction of *OH radicals is non-selective and typically is diffusion-controlled. Four degradation products were detected by *OH radical attacks; two of them already were observed during ozonation, with one as an oxidized ERY molecule and the other as a non-oxidized fragment of the ERY molecule.

Imazalil Degradation upon Applying Ozone—Transformation Products, Kinetics, and Toxicity of Treated Aqueous Solutions

The elimination of the pesticide imazalil (IMZ) spiked into ultrapure water as well as into wastewater applying ozone (O3) and the identification of transformation products was investigated. O3 under hydroxyl radical suppression conditions reacted rapidly with the aliphatic double bond or the imidazole ring in IMZ, yielding several transformation products by partial oxidation. The structures of four oxidation products not yet described were characterized and identified after liquid chromatography coupled with high resolution, high mass accuracy, mass and tandem mass spectrometry (LC/MS and -MSn) in ultrapure water. For two identified transformation products, generated via direct ozone attack on IMZ, formation pathways were proposed. In wastewater, only two of those transformation products were observed. Kinetics studies for the reaction of IMZ with O3, evaluated by the competition kinetic method, resulted in a second-order rate constant kO3,IMZ ∼ (1.02 ± 0.03) × 105 M−1 s−1 at pH 6.6 ± 0.2, indicating that IMZ is completely transformed during the ozonation process. Tests of acute toxicity were performed applying a solution of IMZ in ultrapure water or treated wastewater to Daphnia magna. In both cases the decrease of toxicity was observed after ozone treatment.

Distribution of organochlorine pesticides in surface water and sediments in Lake Volvi (northern Greece)

The objective of the study was to monitor the occurrence of a wide range of OCPs and sediments of the Lake Volvi in northern Greece and to determine their temporal and spatial variations. The samples have been collected seasonally for a period of one year. Solid-phase extraction followed by gas-chromatographic techniques with electron-capture detection was used for the determination of the compounds. The compounds detected were HCB, lindane, β-HCH, heptachlor, methoxychlor, α-endosulphan, and 2,4-DDT, while α-HCH, aldrin, heptachlorperoxide, 4,4-DDE, dieldrin, endrin, 4,4-DDD, β-endosulphan, and 4,4-DDT could not be observed (detection limits ≥1 ng L−1). The frequencies of the compounds detected in the samples varied between 10 and 83% and between 6 and 88% in the water and sediment samples, respectively. Among the 16 OCPs pesticides monitored, only 2,4-DDT and methoxychlor were found in detectable concentrations in sediments throughout the whole sampling period. The water–sediment distribution pattern of the detected compounds reflects the great capacity of the lake sediments to adsorb and accumulate such compounds.

Polar organic pollutants in the Elbe river. Liquid chromatographic-mass spectrometric and flow-injection analysis-mass spectrometric analyses demonstrating changes in quality and concentration during the unification process in Germany.

During the unification process of the two German states from 1989 to 1994, water extracts from the Elbe river were analyzed by gas chromatography-mass spectrometry (GC-MS) and by high-performance liquid chromatography (HPLC) combined with ultraviolet (UV) and/or mass spectrometric detection (MS) in order to monitor the pollutants in one of the most contaminated European rivers. After column chromatography (LC) or flow-injection analysis (FIA) bypassing the analytical column, ionization was performed by a thermospray interface (TSP). Semiquantitative estimations of the pollution of the Elbe were made from the total-ion current traces (TIC) of the extracts. Determination of the total dissolved organic carbon (DOC) indicated a reduction of more than 55% of pollutants in the water phase. The pollutants were identified by tandem mass spectrometry (MS-MS), generating daughter-ion spectra by collision-induced dissociation (CID) using either column chromatography or direct mixture analysis. Compound-specific analyses indicated a reduction in the amount of pollutants as well as a change in their composition. This could be explained by reduced industrial production and by intensified construction of biological sewage treatment plants.

Determination of inorganic and organic priority pollutants in biosolids from meat processing industry

The biosolids (BS) generated in the wastewater treatment process of a meat processing plant were monitored and the priority pollutant content was characterized. The trace metal and organic pollutant content--polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF)--were determined quantitatively and compared to guideline limits established by the US EPA and EU. PCBs were not detected in the solid samples, while trace metals, PAHs and PCDD/PCDF were detected in concentrations below the limits established by international standards. Toxic equivalent factors were evaluated for the biosolids, and the results proved that these wastes can be safely deposited on land or used in combustion/incineration plants. Since no previous data were found for meat processing waste, comparisons were made using municipal sewage sludge data reported in the literature. Since, this report monitored part of the priority pollutants established by the US EPA for meat and poultry processing wastewater and sludge, the results verified that low pollution loads are generated by the meat processing plant located in the southern part of Brazil. However, the BS generated in the treatment processes are in accordance with the limits established for waste disposal and even for soil fertilizer.

Ozone Treatment of Tannery Wastewater Monitored by Conventional and Substance Specific Wastewater Analyses

ABSTRACT Ozone is an unstable and highly reactive gas applied in drinking water or wastewater treatment to oxidize and/or mineralize pollutants. Its application in wastewater treatment leads to a destruction of persistent pollutants combined with an improvement of biodegradability. The oxidation of organic and inorganic compounds in tannery wastewater at different pHs applying O3 was studied. Results after O3-treatment were determined by conventional wastewater parameters, e.g., total organic carbon (TOC), biochemical oxygen demand after 5 days (BOD5), and chemical oxygen demand (COD), as well as by substance-specific mass spectrometric analytical techniques, i.e., gas chromatography—mass spectrometry (GC/MS) and liquid chromatography—mass and tandem mass spectrometry (LC/MS and—MSn). In parallel, variations in the toxicity of the tannery wastewater against water organisms before and after O3-treatment were determined by means of biotoxicity testing, i.e., Daphnia magna Straus and Vibrio fischeri bioassays.