Development of novel thin-film solid-phase microextraction materials based on deep eutectic solvents for preconcentration of trace amounts of parabens in surface waters.

A green and sensitive thin-film solid-phase microextraction method based on deep eutectic solvent was developed that enables simultaneous isolation, preconcentration, and determination of parabens in surface waters. Six new deep eutectic solvents were synthesized and used directly to prepare thin-film coatings on a stainless steel mesh support. Among the compounds obtained, the highest efficiency in the extraction of parabens was found for a material consisting of trihexyltetradecylphosphonium chloride and n-docosanol in a molar ratio of 1:2. For the proposed method, parameters affecting the extraction efficiency of parabens, such as the coating material, the desorption solvent, the volume of the sample, the pH of the sample, the extraction and desorption time, and the salting-out effect, were optimized. Under optimal conditions, the proposed method allowed us to achieve good precision between 3.6 and 6.5% and recovery ranging from 68.1 to 91.4%. The limits of detection range from 0.018 to 0.055 ng/mL.

Variation in the Content of Bioactive Compounds in Infusions Prepared from Different Parts of Wild Polish Stinging Nettle (Urtica dioica L.).

Nettle is a common plant that offers many health benefits and is grown all over the world. The content of active compounds in roots, stems, and leaves was determined based on the extraction procedure optimized using the Central Composite Design. Flavonols, phenolic acids, trigonelline, nicotinamide, nicotinic acids, and short-chain organic acids were determined with the use of LC-MS/MS and capillary isotachophoresis. Trigonelline, which was not previously reported in the roots and stems of nettle, was found in all parts of the plant and considerable variations in its content were observed (2.8-108 µg g-1). Furthermore, the Principal Component Analysis taking into account more variables demonstrated differences in the content of bioactive components between roots and aerial parts of nettle.

Detection of bisphenol A, cumylphenol and parabens in surface waters of Greater Poland Voivodeship.

Amounts of bisphenol A (BPA), 4-cumylphenol (CP) and 5 parabens - methylparaben (MP), ethylparaben (EP), propylparaben (PP), butylparaben (BP) and benzylparaben (BzP) in Greater Poland Voivodeship's surface waters are reported. The water samples were collected from selected 15 locations in 2015-2016 at seven different time points: in March, June, August, and October 2015 and March, June, and September 2016. MP was found in every tested sample with typical concentration at several dozen nanograms per liter and the highest level almost 1600 ng L-1 in a sample collected from the Warta River in October 2015. The other four parabens were determined at considerably lower concentrations than MP at levels not exceeding 100 ng L-1 with PP found at the highest and BzP at the lowest levels. BPA was determined at similar concentration level to parabens - between 5 ng L-1 and 95 ng L-1 and CP was found only in a limited number of samples. Noticeable seasonal changes of paraben concentrations were found showing that for these compounds the pollutant release factor dominates both the biodegradation factor and the water volume factor. These seasonal changes were not observed for BPA and CP. Out of all determined parabens only MP was found at considerably higher concentrations than BPA. However, MP's endocrine properties are much lower than those of BPA posing a lower environmental impact potential than BPA. Influence of other (more endocrine disrupting) parabens is also relatively weak in comparison to BPA due to their considerably lower concentrations in the environment.

Biodegradation of Nonylphenol Monopropoxyethoxylates.

Aerobic biodegradation behavior of nonylphenol monopropoxyethoxylates was investigated in two tests with different inocula-sewage sludge and river water. Both primary biodegradation and formation of different biodegradation intermediates were studied. Primary biodegradation of nonylphenol monopropoxyethoxylates was relatively fast and complete with the sewage sludge as the inoculum. On the other hand, biodegradation with river water as the inoculum was slower and primary biodegradation in this test reached only about 60 % during almost 50 days. The biodegradation intermediates from both oxidative and non-oxidative pathways were found. In the non-oxidative route monopropoxy poly(ethylene glycol)s were observed which indicate existence of the central fission biodegradation pathway. In the oxidative pathway carboxylic acids were identified. The biodegradation intermediates identified with the use of high performance liquid chromatography with mass spectrometric detection persisted for many days in both tests.

Comparison of Biodegradation of Nonylphenol Propoxylates with Usage of Two Different Sources of Activated Sludge.

Aerobic biodegradation behaviour of nonylphenol propoxylates was investigated in two tests with different sewage sludge as inocula. The samples containing target compounds were pre-concentrated using dispersive liquid-liquid microextraction and analysed with the use of high performance liquid chromatography with tandem mass spectrometry. Both primary biodegradation and formation of different biodegradation by-products were studied. Primary biodegradation of nonylphenol propoxylates was relatively slow and reached only about 70 % in over 70 days from the start of the tests. The biodegradation by-products from both oxidative and non-oxidative pathways were found. In the non-oxidative route, shortening of the propoxy chain was observed. In the oxidative pathway carboxylic acids and ketones were identified. The biodegradation by-products identified with the use of mass spectrometric detection also persisted for many days.

Application of dispersive liquid-liquid microextraction followed by HPLC-MS/MS for the trace determination of clotrimazole in environmental water samples.

A method for the analysis of clotrimazole was developed with dispersive liquid-liquid microextraction for sample pre-concentration and HPLC-MS/MS for analysis. A linear ion trap was used for the confirmation of clotrimazole identity in the samples. The developed method enables the analysis of clotrimazole in river water and sewage effluent from wastewater treatment plants with a LOQ of 0.7 ng/L. Environmental monitoring of clotrimazole was undertaken. Samples from river water and sewage effluents were analysed over a one-year period. Clotrimazole was found in every tested sample with concentration range from 1 to 31 ng/L. The amount of clotrimazole in tested samples was highly dependent on sampling season. The highest results were obtained in summer and autumn.

A polydimethylsiloxane/deep eutectic solvent sol-gel thin film sorbent and its application to solid-phase microextraction of parabens.

A novel, efficient and reproducible thin-film solid-phase microextraction method using the polydimethylsiloxane/deep eutectic solvent sol-gel as coating material was developed for preconcentration of parabens from environmental samples. New sorbent materials consisting of polydimethylsiloxane with nine new synthesized deep eutectic solvents were prepared by the sol-gel method, and these materials were used to prepare thin film coatings on a mesh support. Among obtained compounds, the highest efficiency in the extraction of parabens was demonstrated by a sorbent consisting of trihexyltetradecylphosphonium chloride and n-docosanol in a molar ratio 1:2 mixed with polydimethylsiloxane. For the proposed method, the parameters affecting the extraction efficiency of parabens were optimized, including the coating material type based on polydimethylsiloxane/deep eutectic solvent, the sample volume, the salting-out effect, the pH of the sample, the extraction time, the desorption solvent and time. The limits of detection and quantitation were from 0.023 to 0.062 ng mL-1 and 0.076-0.201 ng mL-1, respectively, and the enrichment factors ranged from 174 to 186. Under optimal conditions, the proposed method based on measurements for river and lake water achieved good precision between 2.7 and 5.9% and recovery ranging from 79.1 to 88.1%. The developed method was successfully applied to determine trace levels of parabens in the samples of surface waters collected from rivers and lakes.

Occurrence and dietary risk of bisphenols and parabens in raw and processed cow's milk.

Raw cow's milk collected from farmers and processed cow's milk purchased from local grocery stores were analysed for the presence of six bisphenols (bisphenol A, bisphenol S, bisphenol F, bisphenol AF, bisphenol B, and bisphenol E) and five parabens (methylparaben, ethylparaben, propylparaben, butylparaben, and benzylparaben). The analytes were determined in their unconjugated form and (after enzymatic deconjugation) as the sum of conjugated and unconjugated compounds. The results show the presence of bisphenols mainly in the processed milk bought in stores while parabens were found in all samples of both raw and processed cow's milk. The average concentration of bisphenol A found in milk from cartons (0.87 ng mL-1) was greater than in milk from plastic bottles (0.35 ng mL-1). No such difference was found for parabens. Also, no considerable difference between the content of conjugated and total bisphenols and parabens was found except for ethylparaben. The determined compounds were always found below 2.0 ng mL-1 and calculations of the hazard quotients and the hazard index have shown that consumption of such milk is safe.

The use of a triple quadrupole linear ion trap mass spectrometer with electrospray ionisation for fragmentation studies of selected antifungal drugs.

Fragmentation studies of three antifungal drugs, clotrimazole, fluconazole and clioquinol ,were performed. A triple quadrupole linear ion trap mass spectrometer was used for this purpose. This type of equipment enables MS(3) spectra to be obtained which lead to better understanding of fragmentation pathways. Nevertheless, it is rarely used for fragmentation studies. The results obtained here for the antifungal drugs gave further insight into fragmentation pathways of clotrimazole and fluconazole. Moreover, fragmentation of clioquinol was investigated which had not been presented before.

Biodegradation and photo-Fenton degradation of bisphenol A, bisphenol S and fluconazole in water.

Bisphenol A, bisphenol S, and fluconazole are ubiquitous environmental pollutants and their removal from water is of utmost importance. As the biodegradation of these compounds is usually not enough effective, often other degradation methods are required. The study presents the difference between biodegradation and photo-Fenton degradation with a much higher efficiency obtained in the latter process. Levels of biodegradation and chemical degradation were assessed based on high-performance liquid chromatography determination. Optimization of the photo-Fenton removal of bisphenol A, bisphenol S, and fluconazole resulted in about 100 % primary degradation of both bisphenols during 10-20 min and almost 90 % primary degradation of fluconazole within an hour. Degradation products formed in the process were identified using liquid chromatography with mass spectrometry and showed central scission of bisphenol S with the formation of phenol and sulfuric acid while for bisphenol A and fluconazole the oxidation resulted in much smaller structural changes.

The presence of bisphenol A in the thermal paper in the face of changing European regulations - A comparative global research.

Bisphenol A (BPA) is used as a color developer in a thermal paper that after a heating process reacts with a leuco dye and changes it to a colored form. Receipts from cash registers are considered as the main source of consumer exposure to bisphenols together with polycarbonates and epoxy resins. Levels of BPA and its possible alternatives were determined in thermal paper samples collected between May 2018 and May 2019 in 22 European and 17 non-European countries on all inhabited continents (220 samples in total, 133 of which were from Europe and 87 from other countries). These measurements were intended to check the level of BPA presence in receipts originating from different countries, especially from Europe in the light of changing regulations restricting its use. The effect of thermal printing on developer content was also analyzed, but no major changes in concentrations of bisphenols were observed during the process. Thus, printed receipts could be used for the determination of bisphenol content. Analysis of receipts from 39 countries has shown that BPA is still the most common compound used around the world with 69% samples containing this color developer. Among other tested bisphenols, BPS was used as a color developer in 20% samples, but it was noted that all samples collected from Japan and the United States of America were found to contain only BPS. Other bisphenols (F, AF, E, and B) considered as possible alternatives for BPA were detected only at trace levels or not detected at all, which showed that they were not used as color developers. The relatively large use of BPS as a BPA substitute is worrying because this compound not only has similar endocrine properties but is also poorly biodegradable. Besides, its relatively high polarity facilitates spreading in the environment.

Removal of Bisphenol A and Its Potential Substitutes by Biodegradation.

The possibility of removing bisphenol A and its five potential substitutes (bisphenols S, F, AF, E, and B) was tested using microorganism consortia from river water and activated sludge from municipal and rural wastewater treatment plants. For most bisphenols, biodegradation with activated sludge was faster than with river water and a greater extent of biodegradation was also achieved. However, only bisphenol A and bisphenol F underwent 100% primary biodegradation while other bisphenols degraded no more than about 50% which has some important implications in case of their increased usage. Metabolic activity in biodegradation liquors was also tested and it showed higher activity in the tests with activated sludge than with river water. However, there was no clear connection between the decline of metabolic activity and the extent of biodegradation as decreased activity was observed for two easily degrading bisphenols and two others with little biodegradability. It can be assumed that two different phenomena are involved in this process including depletion of nutrients for easily degradable bisphenol A and absence of nutrients for bacteria incapable of primary degradation of bisphenol AF and bisphenol S.

Application of the electropolymerized poly(3,4-ethylenedioxythiophene) sorbent for solid-phase microextraction of bisphenols.

A new, simple, and effective procedure using poly(3,4-ethylenedioxythiophene)/lignosulfonate electropolymerized sorbent solid-phase microextraction (PEDOT/LS-SPME) combined with LC-MS/MS for determination of bisphenols in environmental water samples was developed. Various parameters influencing the performance of the analytical procedure including the type of sorbent, electropolymerization time, sorbent preconditioning time, extraction time, desorption (time and solvent), and sample pH were investigated and optimized. Under optimal conditions the proposed method allowed us to achieve good precision (n = 5) between 6.0 and 12.1%. The limits of detection were equal to 0.17 µg L-1 for BPA, 0.16 µg L-1 for BPF, 0.07 µg L-1 for BPE, 0.05 µg L-1 for BPB, and 0.027 µg L-1 for BPAF. The proposed method was successfully applied for the determination of bisphenols in aqueous environmental samples.

Fragmentation studies of selected drugs utilized in palliative care.

The results of research on selected drugs used in palliative care are presented, including fentanyl, tramadol, metoclopramide, hyoscine butylbromide, midazolam, haloperidol, levomepromazine and clonazepam. Interpretation of their ESI mass spectra obtained by the use of a triple quadrupole linear ion trap mass spectrometer is given. As a result, fragmentation pathways described in the literature are complemented and presented with more details. On their basis, transitions for quantitative analysis are selected and chromatographic conditions for the determination of the palliative care drugs are proposed as well. These results enable future studies on palliative care drugs in elderly patients including both their quantitation in body fluids and easier identification of their metabolites.

Biodegradation of poly(propylene glycol)s under the conditions of the OECD screening test.

Two poly(propylene glycol)s (PPGs): PPG 425 and PPG 725 were tested under the conditions of the OECD Screening Test with activated sludge as inoculum. Tested PPG were the sole source of organic carbon in the test. Quantitative determination of the biodegradation progress was performed by the HPLC with fluorescence detection after derivatisation of PPG with naphthyl isocyanate. The liquid chromatography-mass spectrometry technique was used for identification and semiquantitative determination of metabolites. Separation of PPG and metabolites from the water matrix was performed by liquid-liquid extraction with chloroform. It was found that the shorter PPG 425 is biodegraded significantly worse than the longer PPG 725 and that biodegradation occurs without shortening of the PPG chain for both PPG. PPG molecules are oxidised to ketones and/or aldehydes during the aerobic biodegradation process.

Comparison of biodegradation of poly(ethylene glycol)s and poly(propylene glycol)s.

The biodegradation of poly(ethylene glycol)s (PEGs) and poly(propylene glycol)s (PPGs), both being major by-products of non-ionic surfactants biodegradation, was studied under the conditions of the River Water Die-Away Test. PEGs were isolated from a water matrix using solid-phase extraction with graphitized carbon black sorbent, then derivatized with phenyl isocyanate and determined by HPLC with UV detection. PPGs were isolated from a water matrix by liquid-liquid extraction with chloroform, then derivatized with naphthyl isocyanate and determined by HPLC with fluorescence detection. The primary biodegradation of both PEGs and PPGs reached approximately 99% during the test. The tests show different biodegradation pathways of PEG and PPG. During PEG biodegradation, their chains are shortened leading to the formation of ethylene glycol and diethylene glycol. During PPG biodegradation, no short-chained biodegradation products were found.

Isotachophoretic determination of carboxylic acids in biodegradation samples.

In the current study a method of isotachophoretic separation of selected carboxylic acids was developed. The method was used for the determination of carboxylated oligo(ethylene glycol)s and their degradation products in biodegradation tests of PEG 250 DA [a mixture of dicarboxylated oligo(ethylene glycol)s]. Two tests were performed in the studies: the Organization for Economic Cooperation and Development (OECD) screening test and the river water die-away test. Both the biodegradation tests proved relatively fast biodegradation of the studied compounds. In the OECD screening test the biodegradation was faster than in the river water die-away test which can be ascribed to a higher concentration of bacteria in the biodegradation liquor. The minimal sample pretreatment and relatively low cost of analysis by the isotachophoretic method used here make it a good alternative to existing methods of carboxylic acids analysis.

Isolation of poly(propylene glycol)s from water for quantitative analysis by reversed-phase liquid chromatography.

Procedures for the isolation of poly(propylene glycol)s (PPGs) from a water matrix have been developed. Solid-phase extraction with an octadecylsilica cartridge and elution with methanol or with a graphitised carbon black cartridge and elution with a mixture of dichloromethane-methanol (4:1) or liquid-liquid extraction with chloroform were all suitable for model samples. However, only liquid-liquid extraction was suitable both for model and real environmental samples. Methods for reversed-phase liquid chromatographic determination of PPGs based on derivatisation and ultraviolet or fluorescence detection have been developed. Four derivatisation agents [3,5-dinitrobenzoyl chloride, phenyl isocyanate, 1-naphthoyl chloride and 1-naphthyl isocyanate (NIC)] were tested. Only NIC was found to give good reproducibility as well as a satisfactory detection limit. Finally, a method with liquid-liquid extraction with chloroform, derivatisation with NIC and liquid chromatographic separation with fluorescence detection was established. The developed method shows a highly correlated linearity of the analytical signals of particular homologues within a wide concentration range (approximately from 0.01 to 10 mg l(-1)). The precision of measurements is satisfactory for homologues having 5-9 oxypropylene subunits and becomes worse with an increase in the number of oxypropylene subunits. The limit of detection is 2 microg l(-1) for the majority of homologues. The method is suitable for the isolation and quantitative determination of PPGs in river water samples and as a tool for biodegradation testing.

Solid-phase extraction combined with dispersive liquid-liquid microextraction, fast derivatisation and high performance liquid chromatography-tandem mass spectrometry analysis for trace determination of short-chained dodecyl alcohol ethoxylates and dodecyl alcohol in environmental water samples.

A new method was developed for preconcentration, derivatisation and analysis of short-chained dodecyl alcohol ethoxylates and dodecyl alcohol. Solid-phase extraction combined with dispersive liquid-liquid microextraction was used for preconcentration of target compounds. Several parameters were optimised including different solid phase extraction sorbents, type and volume of both extracting and dispersive solvents. As a result fast and relatively simple preconcentration method was developed. The analytes were preconcentrated 700 times with the use of small sample volume. The target compounds were derivatised before analysis with the use of newly developed procedure. The derivatisation procedure was made in vial insert and was performed at room temperature with the use of 1-naphthoyl chloride as the derivatisation agent. The developed method was used for the analysis of short-chained dodecyl alcohol ethoxylates and dodecyl alcohol in both sewage effluent from sewage treatment plants and river water samples.

Determination of nonylphenol and short-chained nonylphenol ethoxylates in drain water from an agricultural area.

Water samples from agricultural drains were tested for the presence of nonylphenol and nonylphenol mono- and diethoxylates. The analytes belong to biodegradation products of long-chained nonylphenol ethoxylates, which are used as additives in pesticide formulations. Quantification of these analytes was performed by HPLC with fluorescence detection after isolation by using multi-capillary polytetrafluoroethylene (PTFE) trap extraction. This newly developed technique allowed obtaining about 90% recovery of these analytes in synthetic samples and several percent lower recovery in real samples. Also, no additional sample cleaning was needed before chromatographic analysis. The limit of quantitation for all the analytes was 0.1 microg L(-1). The nonylphenol, nonylphenol mono- and diethoxylates were detected at the concentrations ranging from 0.5 to 6.0 microg L(-1), from 0.2 to 0.7 microg L(-1) and from below 0.02 to 0.4 microg L(-1), respectively. Concentrations of nonylphenol and its derivatives were higher in samples taken in spring than in summer.