L1-7544 — Interim report
1.
Marjeta Česen's PhD thesis: Occurrence, fate and effects of cytostatic residues in the aqueous environment

Cyclophosphamide (CP) and ifosfamide (IF) are still widely prescribed pharmaceuticals for cancer treatment. Concentrations of CP and IF in hospital wastewaters (WWs), wastewater treatment plant (WWTP) influents and effluents and surface waters (SWs) are in up to µg L-1 range, yet the occurrence of their metabolites/transformation products (TPs) is scarce. To reduce the burden of CP and IF in WW, the optimization of biological and abiotic water treatments is essential. In addition, knowledge regarding the TPs formation during such treatments is important as they have unknown toxicity on aquatic ecosystems. The first aim of this doctoral thesis was to investigate the occurrence of CP and IF, their metabolites/TPs 4-ketocyclophosphamide (keto-CP), N-dechloroethylcyclophosphamide or 3-dechlorethylifosfamide (N-decl-CP) and carboxy-cyclophosphamide (carboxy-CP) in the aqueous environment. The analytical method for determination of CP and IF in various aqueous matrices was optimized. In addition, a method for determining keto-CP, N-decl-CP and carboxy-CP in WW was also developed. Solid-phase extraction (SPE) of CP, IF and keto-CP was achieved using Oasis HLBTM, whereas for N-decl-CP and carboxy-CP Isolute ENV+TM cartridges were used. Optimal derivatization of metabolites was achieved with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide with 1 % tert-butyldimethylchlorosilane, whereas for CP and IF trifluoroacetic anhydride was used. Chemical analysis was performed by gas chromatography coupled to mass spectrometry. The methods were assessed in terms of SPE recovery, linearity, instrumental and method repeatability, accuracy and limits of detection (LODs) and quantification (LOQs). The SPE recoveries and LODs were 99 %, 93 %, 58 %, 87 % and 103 % and 2.3 ng L-1, 4.8 ng L-1, 23 ng L-1, 13.1 ng L-1 and 2.0 ng L-1 for CP, IF, carboxy-CP, keto-CP and N-decl-CP, respectively. Furthermore, an interlaboratory comparison was performed for CP and IF, which confirmed the reliability of the analytical method. Seven (for CP) and 6 (for IF) laboratories from Europe and Asia participated within this interlaboratory exercise. The optimized methods were used to analyse aqueous samples collected from different hospitals and their corresponding WWTPs. Cyclophosphamide was detected in two hospital WWs (14 ng L-1 – 22,000 ng L-1), one WWTP influent (19 ng L-1 – 27 ng L-1) and one effluent (17 ng L-1), whereas IF was detected only in one hospital WW sample (48 – 6,800 ng L-1). The concentrations of carboxy-CP, N-decl-CP and keto-CP were 213 ng L-1 – 13,202 ng L-1, 60 ng L-1 – 2,099 ng L-1 and ( LOD – 178 ng L-1 in one hospital WW, respectively, whereas in WWTP influent and effluent they were ( LODs. Various treatment techniques were then assessed in terms of CP and IF removal from WW. Besides biological treatment using attached-growth biomass on MutagTM carriers, different abiotic treatments were examined, including UV irradiation, ozonation (O3), hydrodynamic cavitation (HC) and combinations with hydrogen peroxide (H2O2) as advanced oxidation processes (AOPs). The removal of biological treatment in a flow through bioreactor was 42 % and 18 % for CP and IF, respectively. Hydrodynamic cavitation was the least successful treatment (( 14 % for CP and IF), whereas the highest removal, 99 % for CP and 94 % for IF, were achieved by UV/O3/H2O2 at 5 g L-1 treatment. This AOP, sequentially coupled with biological treatment, resulted in removal ) 99 % for both compounds. The mechanism of TPs formation during selected treatments (UV and UV/H2O2) was investigated in Milli-Q water. The structural elucidation of TPs was achieved using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). The results showed the formation of four TPs of CP (N-decl-CP, keto-CP, CP-TP138a and CP-TP138b) and four TPs of IF (N-dechloroethyl-ifosfamide, keto-ifosfamide, imino-ifosfamide and IF-TP138) during UV treatment. The same TPs were observed during UV/H

D.09 Tutoring for postgraduate students

COBISS.SI-ID: 284558080
2.
Kristina Kotnik: Occurrence, fate and effects of benzodiazepine residues in the aqueous environemnt

The increasing use of pharmaceuticals and personal care products (PPCPs) is leading to their widespread occurrence in the environment. An important class of PPCPs are benzophenones. Although their environmental concentrations are at trace levels, they can induce toxic effects on ecosystems. The aim of this thesis was to provide information on the environmental occurrence, fate and toxicity of eight benzophenones; ketoprofen, its phototransformation products 3-ethylbenzophenone and 3-acetylbenzophenone, and UV filters (benzophenone, 4-hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone and 2,2'-dihydroxy-4-methoxybenzophenone). The thesis describes an analytical procedure for determining the selected benzophenone-derived compounds in surface waters and sediments. The method involves the pre-concentration of water samples by solid phase extraction (SPE) and microwave assisted extraction (MAE) of sediment samples, followed by derivatization and analysis by gas chromatography–mass spectrometry. In terms of SPE, the effects of sample volume and pH, elution solvent, and matrix effects were evaluated, using the Oasis HLB sorbent. The results revealed that sample volume and the type of matrix have no significant influence on the performance of SPE. An acidic pH resulted in equal or higher extraction yields of the investigated compounds. Ethylacetate was chosen as the elution solvent. Overall recoveries up to 96% were achieved. For sediment extraction, the effect of extraction solvent, T, irradiation time and microwave power on MAE yield were investigated. An extraction time of 30 min at 150 °C with the power of 800 W yielded optimal recoveries of 80% to 99%, where the solvent mixture of methanol and acetone (1:1, v/v) with the addition of 5% (w/w) formic acid was used. For derivatization, different types and amounts of derivatizing agent, reaction times and temperatures and solvents were studied. Benzophenone, 3-ethylbenzophenone and 3-acetylbenzophenone were derivatized using 300 µL PFBHA in methanol at 60 °C. 3-acetylbenzophenone showed complete derivatization after 1h, while benzophenone and 3-ethylbenzophenone required a further 14 h. The hydroxylated benzophenones were dissolved in 300 µL of ethyl acetate and derivatized using 30 µL MSTFA (1 h at 60 °C). Derivatized compounds were analysed by GC-MS with the overall achieved limits of detection of 0.1–1.9 ng L-1 for water samples and 0.1–1.4 ng g-1 for sediment samples. The method was applied to the analysis of water and sediment samples from Slovenia and Croatia. Ketoprofen (≤ 2900 ng L-1) and its degradation products (≤ 320 ng L-1) were found in only two rivers (Ljubljanica and Kamniška bistrica), both receiving WWTP effluents, while UV filters were detected in all 14 surface water samples. The most frequently detected compounds were benzophenone and 2-hydroxy-4-methoxybenzophenone, two of the most commonly used UV filters. They were also the most abundant (≤ 190 ng L-1 for benzophenone and ≤ 820 ng L-1 for 2-hydroxy-4-methoxybenzophenone). Results showed that WWTP effluents are an important source of ketoprofen, while sunscreen products washed off during bathing contribute significantly to UV filter contamination of surface waters. Importantly, quantifiable amounts of the two ketoprofen transformation products: 3-ethylbenzophenone (≤ 320 ng L-1) and 3-acetylbenzophenone (≤ 19 ng L-1) in the aqueous environment are reported for the first time. Ketoprofen and its transformation products were not detected in the sediment samples. Benzophenone levels in sediments were ≤ 820 ng g-1, while concentrations of other compounds were lower (≤ 32 ng g-1). Similar to surface waters, the most frequently detected compounds were benzophenone and 2-hydroxy-4-methoxybenzophenone. Laboratory-scale photodegradation experiments using a medium pressure (MP) UV lamp revealed that the degradation of benzophenones follows pseudo-first-order kinetics. Ketoprofen was the mos

D.09 Tutoring for postgraduate students

3.
Environmental Science and Pollution Research

Ester Heath has been since 2012 editor of international journal (IF )2) Environmental Science and Pollution Research.

C.04 Editorial board of an international magazine

COBISS.SI-ID: 2640249