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

Ozonation of ranitidine: Effect of experimental parameters and identification of transformation products

This study focuses on the effect of experimental parameters on the removal of ranitidine (RAN) during ozonation and the identification of the formed transformation products (TPs). The influence of pH value, the initial concentrations, the inorganic and the organic matter on RAN's removal were evaluated. Results indicated high reactivity of RAN with molecular aqueous ozone. Initial ozone concentration and pH were proven the major process parameters. Alkaline pH values promoted degradation and overall mineralization. Dissolved organic matter reacts competitively to RAN with the oxidants (ozone and/or radicals), influencing the target compound's removal. The presence of inorganic ions in the matrix did not seem to affect RAN ozonation. A total of eleven TPs were identified and structurally elucidated, with the complementary use of both Reversed Phase (RP) and Hydrophilic Interaction Liquid Chromatography (HILIC) quadrupole time of flight tandem mass spectrometry (Q-ToF-MS/MS). Most of the TPs (TP-304, TP-315b, TP-299b, TP-333, TP-283) were generated by the attack of ozone at the double bond or the adjacent secondary amine, with the abstraction of NO 2 moiety, forming TPs with an aldehyde group and an imine bond. Oxidized derivatives with a carboxylic group (TP-315a, TP-331a, TP-331b, TP-299a) were also formed. RAN S-oxide was identified as an ozonation TP (TP-330) and its structure was confirmed through the analysis of a reference standard. TP-214 was also produced during ozonation, through the CN bond rupture adjacent to the NO 2 moiety. HILIC was used complementary to RP, either for the separation and identification of TPs with isomeric structures that may have been co-eluted in RPLC or for the detection of new TPs that were not eluted in the RP chromatographic system. Retention time prediction was used as a supporting tool for the identification of TPs and results were in accordance with the experimental ones in both RP and HILIC. © 2016 Elsevier B.V

Radiolytic degradation of 2-methylisoborneol and geosmin in water: reactive radical species and transformation pathways.

Water radiolysis can serve as a useful tool to study the degradation of organic pollutants in water. Manipulation of the radiolytic system enables the selective production of reactive species (RS) with known yields. Our aim was to explore the effects of the radiolytically produced RS on commonly occuring water taste and odor compounds (T&O), 2-methylisoborneol (MIB) and geosmin (GSM). Observed degradation rate constants differ among experimental conditions/dominant RS and follow the order: HO•>H•>>eaq−>(O2−•/HO2•), ranging from 0.002 Gy−1 (O2−•/HO2•) to 0.083 Gy−1 (HO•) for MIB and from 0.006 Gy−1 (O2−•/HO2•) to 0.068 Gy−1 (HO•) for GSM. Degradation by HO• was very efficient, requiring 1.14 and 1.49 μmoles of HO• for each degraded μmole of MIB and GSM, respectively. The oxidative degradation of MIB by HO• proceeds with the production of carbonyl- and hydroxyl-containing transformation products (TPs), leading to linear structures, while for GSM degradation proceeds with ring opening followed by formation of carboxyl-groups. Fewer TPs are produced by HO2•, while degradation with H• led to numerous TPs, via dehydroxylation, dehydration and ring opening. Degradation with eaq−, yielded demethylated and rearranged TPs with formation of double bonds

Degradation of antineoplastic drug etoposide in aqueous environment by photolysis and photocatalysis. Identification of photocatalytic transformation products and toxicity assessment

This study presents the photolytic and photocatalytic degradation of antineoplastic drug etoposide (ETO) in aqueous solutions under UV irradiation. Photolytic degradation of ETO was slow with insufficient mineralization. The quantum yield of ETO's photolytic degradation was calculated and ranged from 0.00029 to 0.00273 mol Einstein−1. Photocatalytic degradation was proven effective, especially at pH 4, where kobs reached 0.963 min−1. Overall, 29 TPs of photocatalysis were detected at pH 4 and 7. Structures were proposed for 23 of them, based on complementary use of low-/high- resolution MS and Quantitative Structure-Retention Relationship (QSRR) prediction models. The main proposed transformations were: addition and/or demethylation of hydroxyl groups, cyclization, dehydrogenation, full or partial deprotection of diols and the loss of sugar or 2,6-dimethoxyphenol moiety. Mineralization did not follow ETO's degradation. Toxicity assessment using Vibrio fischeri bioassay and in silico prediction model revealed the formation of partially recalcitrant and possibly toxic TPs. © 2021 Elsevier B.V

Transient generalized glucocorticoid hypersensitivity

Background Transient generalized glucocorticoid hypersensitivity is a rare disorder characterized by increased tissue sensitivity to glucocorticoids and compensatory hypo-activation of the hypothalamic-pituitary-adrenal axis. The condition itself and the underlying molecular mechanisms have not been elucidated. Objective To present the clinical manifestations, endocrinologic evaluation and transcriptomic profile in a patient with transient generalized glucocorticoid hypersensitivity. Design and Results A 9-year-old girl presented with an 8-month history of clinical manifestations suggestive of Cushing syndrome. Endocrinologic evaluation revealed undetectable 08: 00 h ACTH (<1 pg/mL) and cortisol (0.025 mu g/dL) concentrations, which remained decreased throughout the 24-h period and did not respond to stimulation with ovine CRH. The disease gradually resolved spontaneously over the ensuing 3 months. Sequencing of the human glucocorticoid receptor gene revealed no mutations or polymorphisms. Western blot analysis in peripheral blood mononuclear cells revealed equal protein expression of hGR alpha of the patient in the disease and postresolution phases compared with a control subject. Transcriptomic analysis in peripheral blood mononuclear cells in the disease and postresolution phases identified 903 differentially expressed genes. Of these, 106 genes were up-regulated and 797 were down-regulated in the disease compared with the resolution phase. Bioinformatics analysis on the differentially expressed gene networks revealed Nuclear Factor-kappa B as the predominant transcription factor influencing the expression of the majority of differentially expressed genes. Conclusions Our findings indicate that a transient postreceptor defect, or a virus-or bacterium-encoded molecule, may have enhanced glucocorticoid signal transduction, leading to transient generalized glucocorticoid hypersensitivity and hypo-activation of the HPA axis