An integrated process of biodiesel production from indigenous microalgae in Northern Greece: first results

For environmental, economic and competence reasons, the fuel industry has pushed for alternative fuels in the past few years. One option that is considered are biofuels, which are renewable fuels and have the characteristic of lower or zero emissions of CO2 in the lifecycle, depending on their origin, their production and use. That is done, because the carbon they contain has been committed in the development of organic matter from the atmosphere, which returns after combustion so the balance of emissions throughout the life cycle of biofuel is "theoretically zero

Ozonation of ranitidine: effect of experimental parameters and identification of intermediates

The aim of this study was to reveal the effects of various operational parameters on the ozonation kinetics of the histamine-2 blocker drug ranitidine (RAN) in aqueous solutions and to detect and identify possible transformation products (TPs) of RAN produced during the ozonation experiments. The influence of the solution’s pH value, the initial concentrations of the oxidant and analyte, the matrix effect and the organic matter presence on RAN’s removal were evaluated. Results indicated high reactivity of RAN with molecular aqueous ozone. Initial ozone concentration and pH were proven major process parameters. Alkaline pH values and increased ozone initial concentrations promoted degradation kinetics and overall mineralization. Although RAN mineralization at neutral and acidic pH was restricted (maximum 22%), it increased at pH 10. Dissolved Organic Matter (DOM) acts as an antagonistic agent to RAN degradation, limiting its % removal. The effect of inorganic ions in the matrix did not seem to affect RAN ozonation. Eleven (11) TPs were identified and structurally elucidated, using Reversed Phase (RP) and HILIC LC-Q-ToF-MS. Most of the TPs (P-304, P-315b, P-299b, P-333, P-283) are generated by the attack of ozone at the double bond or the adjacent secondary amine, with the abstraction of NO2 moiety, forming TPs with an aldehyde group and an imine C=N bond. Oxidized derivatives with a carboxylic group (P-315a, P-331a, P-331b, P-299a) are also formed. Ranitidine S-oxide was identified as an ozonation product (P-330) and its structure was confirmed through the analysis of a reference standard. P-214, was also produced during ozonation, through the C-N bond rupture adjacent to the NO2 moiety. HILIC was successfully used complementary to RP, either for the successful separation and identification of isomeric TPs or for the elution of new TPs that were not eluted in the RP chromatographic system. Retention time (tR) prediction was also used as a complementary tool for the identification of TPs. The obtained results supported the proposed structures, since the predicted tR of most compounds in both RP and HILIC were in accordance with the experimental ones

A collaborative evaluation of LC-MS/MS based methods for BMAA analysis: soluble bound BMAA found to be an important fraction.

Exposure to β-Ν-methylamino-l-alanine (BMAA) might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer's disease and Parkinson's disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various analytical methods currently employed is rarely compared. A CYANOCOST initiated workshop was organized aimed at training scientists in BMAA analysis, creating mutual understanding and paving the way towards interlaboratory comparison exercises. During this workshop, we tested different methods (extraction followed by derivatization and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis, or directly followed by LC-MS/MS analysis) for trueness and intermediate precision. We adapted three workup methods for the underivatized analysis of animal, brain and cyanobacterial samples. Based on recovery of the internal standard D3BMAA, the underivatized methods were accurate (mean recovery 80%) and precise (mean relative standard deviation 10%), except for the cyanobacterium Leptolyngbya. However, total BMAA concentrations in the positive controls (cycad seeds) showed higher variation (relative standard deviation 21%-32%), implying that D3BMAA was not a good indicator for the release of BMAA from bound forms. Significant losses occurred during workup for the derivatized method, resulting in low recovery ( < 10%). Most BMAA was found in a trichloroacetic acid soluble, bound form and we recommend including this fraction during analysis

Multi-year interlaboratory exercises for the analysis of illicit drugs and metabolites in wastewater:development of a quality control system

Thirty-seven laboratories from 25 countries present the development of an inter-laboratory testing scheme for the analysis of seven illicit drug residues in standard solutions, tap- and wastewater. Almost 10 000 concentration values were evaluated: triplicates of up to five samples and 26 laboratories per year. The setup was substantially improved with experiences gained across the six repetitions (e.g. matrix type, sample conditions, spiking levels). From this, (pre-)analytical issues (e.g. pH adjustment, filtration) were revealed for specific analytes which resulted in formulation of best-practice protocols for inter-laboratory setup and analytical procedures. The results illustrate the effectiveness of the inter-laboratory setup to assess laboratory performance in the framework of wastewater-based epidemiology. The exercise proved that measurements of laboratories were of high quality (>80% satisfactory results for six out of seven analytes) and that analytical follow-up is important to assist laboratories in improving robustness of wastewater-based epidemiology results