Comparison of phosphodiesterase type V inhibitors use in eight European cities through analysis of urban wastewater

In this work a step forward in investigating the use of prescription drugs, namely erectile dysfunction products, at European level was taken by applying the wastewater-based epidemiology approach. 24-h composite samples of untreated wastewater were collected at the entrance of eight wastewater treatment plants serving the catchment within the cities of Bristol, Brussels, Castellón, Copenhagen, Milan, Oslo, Utrecht and Zurich. A validated analytical procedure with direct injection of filtered aliquots by liquid chromatography-tandem mass spectrometry was applied. The target list included the three active pharmaceutical ingredients (sildenafil, tadalafil and vardenafil) together with (bio)transformation products and other analogues. Only sildenafil and its two human urinary metabolites desmethyl- and desethylsildenafil were detected in the samples with concentrations reaching 60 ng L−1. The concentrations were transformed into normalized measured loads and the estimated actual consumption of sildenafil was back-calculated from these loads. In addition, national prescription data from five countries was gathered in the form of the number of prescribed daily doses and transformed into predicted loads for comparison. This comparison resulted in the evidence of a different spatial trend across Europe. In Utrecht and Brussels, prescription data could only partly explain the total amount found in wastewater; whereas in Bristol, the comparison was in agreement; and in Milan and Oslo a lower amount was found in wastewater than expected from the prescription data. This study illustrates the potential of wastewater-based epidemiology to investigate the use of counterfeit medication and rogue online pharmacy sales

Reduction of interferences in the determination of lanthanides, actinides and transition metals by an octopole collision/reaction cell inductively coupled plasma mass spectrometer – Application to the analysis of Chios mastic

Lanthanides, actinides and transition metals have demonstrated the ability to be used as fingerprint for the specification of the authenticity and geographical origin of food commodities. Therefore, the existence of analytical methods for their determination is of great importance, since both producers and consumers could benefit. An inductively coupled plasma mass spectrometric (ICP-MS) method was developed and validated for the determination of these elements in a Protected Designation of Origin product, the Chios mastic gum. A multivariate strategy for the microwave digestion of mastic was carried out. Five factors were studied and optimized. Hold time, temperature and HF volume, were found to be the most critical factors, so further optimization was performed. Molecular oxide (MO+, MO2+) and hydroxide (MOH+) interferences were investigated. The capability of an octopole collision/reaction cell ICP-MS to attenuate or remove these interferences was studied. The effect of instrumental parameters on MO+/M+, MOH+/M+ and MO2+/M+ ratios was studied to ensure that observed changes were a result of alteration of the parameter and not due to random fluctuations. Moreover, the effect of kinetic energy discrimination to suppress these species was demonstrated. The energy losses of ions were measured from stopping curves and the estimation of collision cross sections was done. Efficiencies of He and H2 gases were compared and H2 was finally selected for all elements. The calculated recoveries were ranged between 70 and 70% and 104% and the relative standard deviations (intermediate precision) were generally under 16%. The limits of detection were 0.07 ng g−1 (Dy, Th) – 1.4 ng g−1 (Ce). © 2017 Elsevier B.V

Attenuation of interference in collision/reaction cell inductively coupled plasma mass spectrometry, using helium and hydrogen as cell gases-application to multi-element analysis of mastic gum

A collision/reaction cell ICP-MS was used to develop a method for the multi-element determination of Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Nb, Mo, Ag, Cd, Sb, Cs, Ba, Hg and Pb in mastic gum. Evaluation of helium and hydrogen as cell gases took place and their ability to reduce several types of interference arising from a Si, S, P, C, Cl and F based matrix was investigated. Likewise, much polyatomic interference was attenuated efficiently by the effect of kinetic energy discrimination. Moreover, a study of stopping curve measurements was performed. Thus, measurements of the ion loss caused by collisions, reaction cross-sections given by the Langevin-Gioumousis- Stevenson model and collision cross-sections were carried out. The method was validated and the calculated recoveries for all elements (at three concentration levels) were ranged between 92.6% (Ti) and 105% (Ag) and the relative standard deviation (%RSD) of reproducibility was ranged between 1.6% (Co) and 9.9% (Ca). The limits of detection ranged between 0.11 ng g-1 (Cs) and 1.12 μg g-1 (Ca). The trueness of the method was also checked by the analysis of a standard reference material (SRM, 1573a tomato leaves). © 2014 The Royal Society of Chemistry

An integrated approach to MS-based identification and risk assessment of pharmaceutical biotransformation in wastewater

The omnipresence of pharmaceuticals at relatively high concentrations (μg/L) in environmental compartments indicated their inadequate removal by wastewater treatment plants. As such, batch reactors seeded with activated sludge were set up to assess the biotransformation of metformin, ranitidine, lidocaine and atorvastatin. The main objective was to identify transformation products (TPs) through the establishment of an integrated workflow for suspect and non-target screening based on reversed phase liquid chromatography quadrupole-time-of-flight mass spectrometry. To support the identification, hydrophilic interaction liquid chromatography (HILIC) was used as a complementary tool, in order to enhance the completeness of the developed workflow by identifying the more polar TPs. The structure assignment/elucidation of the candidate TPs was mainly based on interpretation of MS/MS spectra. Twenty-two TPs were identified, with fourteen of them reaching high identification confidence levels (level 1: confirmed structure by reference standards and level 2: probable structure by library spectrum match and diagnostic evidence). Finally, retrospective analysis in influent and effluent wastewater was performed for the TPs for four consecutive years in wastewater sampled in Athens, Greece. The potential toxicological threat of the compounds to the aquatic environment was assessed and atorvastatin with two of its TPs showed a potential risk to the aquatic organisms. © 2021 Elsevier B.V

Development, validation and accreditation of a method for the determination of Pb, Cd, Cu and As in seafood and fish feed samples

A rapid, sensitive, accurate and precise method for the determination of Pb, Cd, As and Cu in seafood and fish feed samples by Simultaneous Electrothermal Atomic Absorption Spectrometry was developed in regard to Council Directive 333/2007EC and ISO/IEC 17025 (2005). Different approaches were investigated in order to shorten the analysis time, always taking into account the sensitivity. For method validation, precision (repeatability and reproducibility) and accuracy by addition recovery tests have been assessed as performance criteria. The expanded uncertainties based on the Eurachem/Citac Guidelines were calculated. The method was accredited by the Hellenic Accreditation System and it was applied for an 8 years study in seafood (n = 202) and fish feeds (n = 275) from the Greek market. The annual and seasonal variation of the elemental content and correlation among the elemental content in fish feeds and the respective fish samples were also accomplished © 2013 Elsevier Ltd. All rights reserved

Evaluation of Different Modifiers for the Determination of Arsenic in Leachate Samples from Sanitary Landfills by Electrothermal Atomic Absorption Spectrometry

The aim of the present work was to develop and validate a rapid and accurate method of arsenic determination in leachate samples by electrothermal atomic absorption spectrometry. Leachate samples from sanitary landfills are considered difficult samples to analyze due to severe matrix interferences. A comparative study of various chemical modifiers was performed: Pd, Mg, Au, Pt, Ru, Rh, Ir, C 6H 8O 7 (citric acid), Pd + Mg, Ir + Mg, and the permanent modifier Zr - Ir.Among the modifiers tested, the mixture 5 μg Ir + 40 μg Mg provided the best performance, followed by the permanent modifier Zr - Ir (a coating of 200 μg Zr + 20 μg Ir). The permanent modifier was finally chosen due to the decreased background signal and sufficient sensitivity.In order to investigate the presence of matrix interference and exploit the possibility of performing calibrations by simple aqueous solutions, calibration with aqueous standards, matrix matched standards and with standard additions was performed. It was observed that, in the presence of the Zr - Ir permanent modifier, the slopes of the calibration curve and the matrix-matched/standard addition curves were statistically different (checked by t-test). The recoveries from matrix-matched calibrations for three concentration levels were ranged between 96.4% and 100%. Precision experiments were also performed and the relative standard deviation (%RSD) for four different concentrations was ≤10%. The method was applied to the determination of arsenic in leachate samples collected in the solid waste sanitary landfill of Ano Liossia, Attika, Greece. © 2012 Copyright Taylor and Francis Group, LLC

Advanced multivariate techniques for the classification and pollution of marine sediments due to aquaculture

Aquaculture production has globally increased and its environmental impact is not well understood and assessed yet. Therefore, in this work nine metals and metalloids (Cu, Cd, Pb, Hg, Ni, Fe, Mn, Zn and As) and three nutrients (P, N and C) that seem to accumulate in marine sediments, were determined under the fish cages (zero distance) and about 50 and 100 m away from them, in three aquacultures in Greece. The analysis of these data is crucial due to the negative impact of the intensive aquaculture activities on fish population, human health and marine environment. This study investigated the environmental impact associated with aquaculture cages on marine sediments, using Supervised Artificial Neural Networks (ANNs) in parallel with Classification Trees (CTs). Optimised models were constructed in order to detect the significance of each variable, predict the origin of the sediment samples and successfully visualise their results. Three popular ANN architectures, as multi-layer perceptrons (MLPs), radial basis function (RBF) and counter propagation artificial neural networks (CP-ANNs) were used to assess the impact of the intensive aquaculture activities on marine sediments. In addition, more traditional multivariate chemometric techniques like CTs were applied to the same data set for comparison purposes. The modelling study showed that P, N, Cu, Cd were the most critical (and polluting) factors of those metals studied. Moreover, single-element models achieved elevated predictive percentages. The results were justified due to the usual practices used for fish feeding or cages maintenance. © 2020 Elsevier B.V