•Metabolomic investigations were performed in plasma of smokers and non-smokers.•Targeted fatty acid analysis revealed an alteration in smokers fatty acid profiles.•A HILIC–MS/MS method was developed for phospholipid profile determination in plasma.•The HILIC–MS/MS method was validated according to FDA-guidelines.•PC and PE species profiles are significantly altered in plasma of smokers.Mass spectrometry is an ideal tool for investigations of the metabolome in human plasma. To investigate the impact of smoking on the human metabolome, we performed an untargeted metabolic fingerprinting using GC–TOF–MS with EDTA-plasma samples from 25 smokers and 25 non-smokers. The observed elevated levels in the monounsaturated fatty acids (MUFAs) in smokers were verified by a targeted analysis using GC–FID, which revealed also significantly alterations in saturated and polyunsaturated fatty acids in smokers (p < 0.05, Mann–Whitney U test). Since the main fraction of fatty acids in plasma is esterified to phospholipids, we analyzed phosphatidylcholine (PC) and phosphatidylethanolamine (PE) species composition in the plasma samples of the same subjects. The profiles of 39 PC and 40 PE species were analyzed with a newly developed and validated HILIC–ESI–MS/MS method. We were able to baseline separate the two lipid classes (PC from PE) by maintaining co-elution of individual lipid species of each class. The method shows a linear range from 0.5 μM to 2000 μM and an inter- and intraday coefficient of variation (CV) < 20% across all analytes. Application of the validated method to the plasma samples of smokers and non-smokers, derived from a diet-controlled smoking study, revealed significantly elevated levels of PC and PE species containing MUFAs in smokers.In summary, we could demonstrate that there is a significantly altered total fatty acid profile, with increased MUFAs, in the plasma of smokers compared to non-smokers. Results obtained with the new HILIC–MS/MS method indicate that the altered fatty acid profile is also reflected in the PC and PE profile of smokers.

In this study we summarize the possibilities and limitations of a conductometric measurement principle for soot sensing. The electrical conductivity of different carbon blacks (FW 200, lamp black 101, Printex 30, Printex U, Printex XE2, special black 4, and special black 6), spark discharge soot (GfG), and graphite powder was measured by a van der Pauw arrangement. Additionally the influence of inorganic admixtures on the conductivity of carbonaceous materials was proven to follow the percolation theory. Structural and oxidation characteristics obtained with Raman microspectroscopy and temperature programmed oxidation, respectively, were correlated with the electrical conductivity data. Moreover, a thermophoretic precipitator has been applied to deposit soot particles from the exhaust stream between interdigital electrodes. This combines a controlled and size independent particle collection method with the conductivity measurement principle. A test vehicle was equipped with the AVL Micro Soot Sensor (photoacoustic soot sensor) to prove the conductometric sensor principle with an independent and reliable technique. Our results demonstrate promising potential of the conductometric sensor for on-board particle diagnostic. Furthermore this sensor can be applied as a simple, rapid, and cheap analytical tool for characterization of soot structure.

In this study, we investigated several coatings for high-temperature, high-capacity, and high-efficiency denuder-based NO2 removal, with the scope to face the harsh conditions and requirements of automotive exhaust gas sampling. As first coating, we propose a potassium iodide (KI)/polyethylene glycol coating with a high removal efficiency (ε > 98 %) for about 2 h and 50 ppm NO2 at room temperature (298 K). At elevated temperatures (423 K), the initial capacity (100 ppmh) is decreased to 15 ppmh. Furthermore, this is the first proposal of the ionic liquid methyl-butyl-imidazolium iodide ([BMIm+][I−]) as denuder coating material. At room temperature, this ionic liquid exhibits far greater capacity (300 ppmh) and NO2 removal efficiency (ε > 99.9 %) than KI. Nevertheless, KI exhibits a slightly (~10 %) higher capacity at elevated temperatures than [BMIm+][I−]. Both coatings presented are suitable for applications requiring selective denuding of NO2 at temperatures up to 423 K.

•We first developed potency assay for drug containing release-active form of substance.•The assay focused on the ability of the drugs to modify antigen-antibody interaction.•Importance of the source of diclofenac was studied.•Antigen concentration is a critical parameter for the proposed assay.We report on a specially designed diclofenac-ELISA for the determination of diclofenac in the presence of release-active forms of diclofenac in lactose dissolved in water solutions according to a predefined schedule in single-blind experiments. In accordance with the objective of this project, a number of experiments were conducted to determine the optimal ELISA conditions for detecting potential modulatory effects of release-active forms of diclofenac depending on their ability to affect the binding of diclofenac to anti-diclofenac antibodies. As a feature, the diclofenac antibodies were previously incubated with manufactured pharmaceutical samples containing release-active forms of diclofenac or placebo. For comparison of the sample types, measured in ELISA optical densities were chosen. For statistic analysis, Student's two-sample t-test and single-factor ANOVA were applied. The extremely low concentrations of diclofenac of 0.01, 0.05 and 0.1 ng mL− 1 seem most appropriate for routine assay performance. The source of diclofenac used for standard solution preparation is not important but it could be important as the source of diclofenac for release active form of diclofenac preparation. As an outcome, the ELISA appeared to be suitable for the detection of the modifying effects of release-active forms of diclofenac toward the pharmaceutical substance in vitro.Download full-size image

An often referred feature of ambient and combustion aerosol samples is their ratio of elemental carbon (EC) to organic carbon (OC). Thermo-optical methods are commonly used to determine this ratio. As those methods generally consist of a heating step under inert atmosphere for OC quantification and a consecutive combustion step under oxidative atmosphere for EC quantification, combustion catalysts may drastically impact the measured EC/OC value. Such catalysts may be minerals, e.g. inorganic salts or oxides, that are mixed with the soot and may stem from various sources.In this study, the impact of varying content of different salts internally mixed with soot on soot structure and oxidation reactivity was studied. For this purpose, a novel method for preparation of model soot aerosols internally mixed with different inorganic salts (CaSO4, Ce(SO4)2/CeO2, Na2SO4, or NaCl) at different contents was applied by spraying aqueous salt solutions into a propane diffusion flame. Proof of production of internal mixtures of soot with the different salts was given by scanning electron microscopy (SEM). Raman microspectroscopy (RM) was utilized to characterize the soot structure. Soot oxidation reactivity was analyzed by temperature-programmed oxidation (TPO). It could be proven that doping of the soot with inorganic salts does not impact the soot structure. However, soot oxidation reactivity is strongly enhanced with increasing salt content resulting in a TPO emission maximum shifted by up to 200 K towards lower temperatures. Our results pose questions on the feasibility of thermo-optical methods for the determination of EC/OC values of carbonaceous aerosols in the presence of internally mixed minerals.Download high-res image (95KB)Download full-size image