Extension of Biodiesel Aging Mechanism-the Role and Influence of Methyl Oleate and the Contribution of Alcohols Through the Use of Solketal.

The energy crisis and dependence on fossil fuels forces societies to develop alternative pathways to secure energy supplies. Therefore, non-fossil fuels such as biofuels and e-fuels can help counteract the resulting demand for existing combustion engines. However, biofuels, like biodiesel, have disadvantages in terms of oxidation stability.

Sources of nitrogen heterocyclic PAHs (N-HETs) along a riverine course.

For the first time the occurrence of 26 nitrogen heterocyclic polyaromatic hydrocarbons (N-HETs) and the antiepileptic drug carbamazepine (CBZ) as a marker for anthropogenic influence was determined in an entire river system and its influents. Besides the investigation of diurnal and annual variations in concentrations, dilution and load calculations, the aims were to facilitate transferability to other rivers by identifying sources of the different substances. To create a sufficient database over 180 aqueous samples from the River Fuhse (Lower Saxony, Germany), its catchment area, effluents of municipal and industrial wastewater treatment plants (WWTPs) and rainwater were analyzed.

Development and application of a simultaneous SPE-method for polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, heterocyclic PAHs (NSO-HET) and phenols in aqueous samples from German Rivers and the North Sea.

Polycyclic aromatic hydrocarbons (PAHs), heterocyclic PAHs (NSO-HETs), alkylated PAHs and phenols are known as the prevailing contaminants in groundwater at tar contaminated sites. Besides these local sources, the concentrations and the distribution in particular of NSO-HETs in environmental samples, such as rivers, have received notably less attention. To investigate their occurrence in river basins two sensitive analytical methods for the simultaneous extraction of 86 substances including NSO-HETs, classical EPA-PAHs, alkylated PAHs and phenols were developed: liquid-liquid extraction for the whole water phase and solid phase extraction for the dissolved water phase only.

Monitoring of microbially mediated corrosion and scaling processes using redox potential measurements.

The use of redox potential measurements for corrosion and scaling monitoring, including microbially mediated processes, is demonstrated. As a case study, monitoring data from 10years of operation of an aquifer thermal energy storage (ATES) site located in Berlin, Germany, were examined. (Fe(2+))-activities as well as [Fe(3+)]-build up rates were calculated from redox potential, pH, conductivity, temperature and dissolved oxygen measurements.

Occurrence and fate of the antidiabetic drug metformin and its metabolite guanylurea in the environment and during drinking water treatment.

Metformin, an antidiabetic drug with one of the highest consumption rates of all pharmaceuticals worldwide, is biologically degraded to guanylurea in wastewater treatment plants. Due to high metformin influent concentrations of up to 100 μg/L and its high but incomplete degradation both compounds are released in considerable amounts of up to several tens of μg/L into recipient rivers. This is the first systematic study on their environmental fate and the effectiveness of treatment techniques applied in waterworks to remove metformin and guanylurea from surface water influenced raw waters.

Identification of ozonation by-products of 4- and 5-methyl-1H-benzotriazole during the treatment of surface water to drinking water.

During the treatment of surface water to drinking water, ozonation is often used for disinfection and to remove organic trace substances, whereby oxidation by-products can be formed. Here we use the example of tolyltriazole to describe an approach for identifying relevant oxidation by-products in the laboratory and subsequently detecting them in an industrial-scale process. The identification process involves ozonation experiments with pure substances at laboratory level (concentration range mg L(-1)).

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

Purpose: The 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.

Methods: For the separation and detection of the OPs, several analytical techniques, including nuclear magnetic resonance experiments, were applied.

A new approach to data evaluation in the non-target screening of organic trace substances in water analysis.

Non-target screening via high performance liquid chromatography-mass spectrometry (HPLC-MS) has gained increasingly in importance for monitoring organic trace substances in water resources targeted for the production of drinking water. In this article a new approach for evaluating the data from non-target HPLC-MS screening in water is introduced and its advantages are demonstrated using the supply of drinking water as an example. The crucial difference between this and other approaches is the comparison of samples based on compounds (features) determined by their full scan data.

Correlation of six anthropogenic markers in wastewater, surface water, bank filtrate, and soil aquifer treatment.

Six trace contaminants (acesulfame (ACE), sucralose (SUC), carbamazepine (CBZ), diatrizoic acid (DTA), 1H-benzotriazole (BTZ) and its 4-methyl analogue (4-TTri)) were traced from wastewater treatment plants (WWTPs) to receiving waters and further to riverbank filtration (RBF) wells to evaluate their prediction power as potential wastewater markers. Furthermore, the persistence of some compounds was investigated in advanced wastewater treatment by soil aquifer treatment (SAT). During wastewater treatment in four conventional activated sludge WWTPs ACE, SUC, and CBZ showed a pronounced stability expressed by stable concentration ratios in influent (in) and effluent (out) (ACE/CBZ: in45, out40; SUC/CBZ: in1.

Inside-sediment partitioning of PAH, PCB and organochlorine compounds and inferences on sampling and normalization methods.

Comparability of sediment analyses for semivolatile organic substances is still low. Neither screening of the sediments nor organic-carbon based normalization is sufficient to obtain comparable results. We are showing the interdependency of grain-size effects with inside-sediment organic-matter distribution for PAH, PCB and organochlorine compounds.

Combination of different liquid chromatography/mass spectrometry technologies for the identification of transformation products of rhodamine B in groundwater.

Rhodamine B and its five de-ethylated transformation products could be identified in a groundwater sample. Using high-performance thin-layer chromatography (HPTLC) six fluorescent zones were detected in the sample. In order to identify the compounds in the zones by exact mass mass spectrometry (MS) measurements and tandem mass spectrometry (MS/MS), they were extracted from the HPTLC plate for subsequent analysis by nano-chip high-performance liquid chromatography quadrupole-time-of-flight mass spectrometry (nano-chip HPLC/QTOFMS).

Using sequential injection analysis for fast determination of phosphate in coastal waters.

A sequential injection analysis system (SIA) is described which is suited for the fast determination of filterable molybdate reactive phosphate (FRP, 0.2mum) in coastal waters. It processes up to 270 samples per hour with a detection limit (3sigma) of 0.

Occurrence and distribution of triclosan in the German Bight (North Sea).

The potential of triclosan (TCS) acting as an endocrine disruptor has led to growing concern about the presence of TCS in the environment. In this study, seawater samples were collected from the German Bight during sampling campaigns conducted with the German research ships Gauss and Ludwig Prandtl. TCS was determined both in the dissolved phase and in the suspended particulate matters with concentrations ranging 0.

Determination of 10 particle-associated multiclass polar and semi-polar pesticides from small streams using accelerated solvent extraction.

A new analytical method using accelerated solvent extraction was developed for the determination of 10 particle-associated polar and semipolar pesticides. In addition, six deuterated analogues of the target compounds were evaluated as internal standards. The method yielded acceptable accuracy (73-103% recovery) and precision (<25% relative standard deviation) for eight compounds.

Air-sea exchange fluxes of synthetic polycyclic musks in the North Sea and the Arctic.

Synthetic polycyclic musk fragrances Galaxolide (HHCB) and Tonalide (AHTN) were measured simultaneously in air and seawater in the Arctic and the North Sea and in the rural air of northern Germany. Median concentrations of gas-phase HHCB and AHTN were 4 and 18 pg m(-3) in the Arctic, 28 and 18 pg m(-3) in the North Sea, and 71 and 21 pg m(-3) in northern Germany, respectively. Various ratios of HHCB/AHTN implied that HHCB is quickly removed by atmospheric degradation, while AHTN is relatively persistent in the atmosphere.

Occurrence and air-sea exchange of phthalates in the Arctic.

Air and seawater samples were taken simultaneously to investigate the distribution and air-sea gas exchange of phthalates in the Arctic onboard the German Research Ship FS Polarstern. Samples were collected on expeditions ARK XX1&2 from the North Sea to the high Arctic (60 degrees N-85 degrees N) in the summer of 2004. The concentration of sigma6 phthalates (dimethyl phthalate (DMP), diethyl phthalate (DEP), di-i-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), butylbenzyl phthalate (BBP), and diethylhexyl phthalate (DEHP)) ranged from 30 to 5030 pg L(-1) in the aqueous dissolved phase and from 1110 to 3090 pg m(-3) in the atmospheric gas phase.

Development and application of a laboratory flux measurement system (LFMS) for the investigation of the kinetics of mercury emissions from soils.

Recent measurements at different locations suggest that the emission of mercury from soils may play a more pronounced role in the global mercury cycle as suggested by global emission inventories and global mercury cycling models. For up scaling and modelling of mercury emissions from soils a comprehensive assessment of the processes controlling the emission of mercury from soils is imperative. We have developed a laboratory flux measurement system (LFMS) to study the effect of major environmental variables on the emission of mercury under controlled conditions.

Atmospheric concentrations and air-sea exchanges of nonylphenol, tertiary octylphenol and nonylphenol monoethoxylate in the North Sea.

Concentrations of nonylphenol isomers (NP), tertiary octylphenol (t-OP) and nonylphenol monoethoxylate isomers (NP1EO) have been simultaneously determined in the sea water and atmosphere of the North Sea. A decreasing concentration profile appeared following the distance increasing from the coast to the central part of the North Sea. Air-sea exchanges of t-OP and NP were estimated using the two-film resistance model based upon relative air-water concentrations and experimentally derived Henry's law constant.

Liquid chromatography-tandem mass spectrometry analysis of estrogenic compounds in coastal surface water of the Baltic Sea.

An analytical method has been developed for the determination of five naturally occurring estrogens (estradiol, estriol, estrone, genistein, daidzein), one synthetic hormone (ethynylestradiol) and three xenoestrogens (4-nonylphenol (NP), 4-tert-octylphenol (4-tert-OP), bisphenol A (BPA)) in coastal marine waters. The procedure includes a solid-phase extraction of approx. fifty litres of water samples on the solid-phase copolymer Oasis HLB followed by a clean-up on silica.

Development and characterisation of a new interface for coupling capillary LC with collision-cell ICP-MS and its application for phosphorylation profiling of tryptic protein digests.

A comparison of different nebulisers for direct hyphenation of capillary and nano liquid chromatography (Cap-LC, Nano-LC) and quadrupole-based collision cell inductively coupled plasma mass spectrometry (CC-ICP-MS) for phosphorylation profiling of tryptic protein digests is described. Helium was used as cell gas and specially tuned instrumental conditions were used to achieve background minimisation at the mass of phosphorus, because of kinetic energy discrimination of the interfering polyatomic ions. The proposed set-up is based on a modified capillary electrophoresis interface and a home-made 4 mL spray chamber.

Determination of herbicides in stemflow and throughfall of beeches (Fagus sylvatica L.) and in rainfall.

The pesticide contamination of water samples collected in and nearby a beech forest in northern Germany was evaluated. For this purpose, a method for the collection of water samples from stemflow and throughfall of beeches (Fagus sylvatica L.) and rainfall was developed in response to the demands for the analysis of organic contaminants in water samples.

Simultaneous determination of alkylphenol ethoxylates and their biotransformation products by liquid chromatography/electrospray ionisation tandem mass spectrometry.

Reversed-phase LC-MS/MS is used to determine major estrogenic alkylphenol ethoxylates (APEOs) and their biotransformation products. It allows the simultaneous analysis of eight APEOs, alkylphenoxy carboxylates (APECs) and alkylphenols (APs) in sewage treatment plant (STP) effluents in the same extract after solid-phase enrichment on polymeric Oasis HLB. As precursor ions, [APEO + NH4]+, [APEC - H]- and [AP - H]- were monitored.

Bioassay-directed chemical analysis utilizing LC-MS: a tool for identifying estrogenic compounds in water samples?

A bioassay-directed chemical analysis (BDCA) scheme has been developed which combines a yeast screen for estrogenic activity with LC-MS detection after liquid-liquid extraction and fractionation by size exclusion chromatography. Focusing on sewage-treatment plant (STP) effluents, the approach aims at characterizing the substances responsible for estrogenic effects in aquatic systems. Initial results show a strong response of STP effluent extracts in the yeast screen.