Enantiomeric determination of azole antifungals in wastewater and sludge by liquid chromatography–tandem mass spectrometry

Occurrence and distribution of azole antifungal agents in eight urban Romanian waste water treatment plants

Azole compounds are utilized to combat fungal infections in plants to protect them and also used for treating mycosis in humans. The LC-MS/MS method is a technique that combines liquid chromatography with tandem mass spectrometry for analysis of twelve azole compounds from wastewater (influent, effluent) and sewage sludge. The compounds were isolated from waste water using automatic extraction in the solid phase. Sludge samples were dried by lyophilization, after which they were subjected to ultrasound extraction with methanol. The quantification limits ranged from 0.3 ng/L (clotrimazole-CLO and prochloraz-PRO) to 1.5 ng/L (tetraconazole-TEB and penconazole-PEN), for wastewater samples and for sewage sludge, the LOQs ranged from 0.1 ng/g to 0.6 ng/g. High concentrations of climbazole-CLI (207-391 ng/L), tebuconazole (92-424 ng/L), and clotrimazole (6.9-93-ng/L) were observed in influent samples of the 8 urban wastewater treatment plants, followed by fluconazole (49.3-76.8 ng/L), and prochloraz (7.3-72 ng/L). The ∑Azoles had a maximum of 676 ng/L in the Galati effluent, followed by the Bucharest station 357 ng/L, and 345 ng/L in the Braila effluent. The highest value of the daily mass loading (input) level was observed for climbazole, 265 mg/day/1000 in Iasi station, followed by tebuconazole, 238 mg/day/1000 people in the Bucharest station, and 203 mg/day/1000 people for climbazole in the Targoviste station. The daily mass emission presented values between 0.7 and 247 mg/day/1000 people. The highest emissions were observed for climbazole, 247 mg/day/1000 people in Braila station; 174 mg/day/1000 people in the Iasi station and 129 mg/day/1000 people in the Bucharest station. The concentrations of climbazole detected in the effluent can present a high risk for the plants Lemna minor and Navicula pelliculosa. Clotrimazole may present a high risk to the plant Desmodesmus subspicatus and to the invertebrate Daphnia magna. PRO may present high risk to the invertebrate Mysidopsis Bahia.

Antifungal drugs in the aquatic environment: A review on sources, occurrence, toxicity, health effects, removal strategies and future challenges

Fungal infections pose a significant global health burden, resulting in millions of severe cases and deaths annually. The escalating demand for effective antifungal treatments has led to a rise in the wholesale distribution of antifungal drugs, which consequently has led to their release into the environment, posing a threat to ecosystems and human health. This article aims to provide a comprehensive review of the presence and distribution of antifungal drugs in the environment, evaluate their potential ecological and health risks, and assess current methods for their removal. Reviewed studies from 2010 to 2023 period have revealed the widespread occurrence of 19 various antifungals in natural waters and other matrices at alarmingly high concentrations. Due to the inefficiency of conventional water treatment in removing these compounds, advanced oxidation processes, membrane filtration, and adsorption techniques have been developed as promising decontamination methods.In conclusion, this review emphasizes the urgent need for a comprehensive understanding of the presence, fate, and removal of antifungal drugs in the environment. By addressing the current knowledge gaps and exploring future prospects, this study contributes to the development of strategies for mitigating the environmental impact of antifungal drugs and protecting ecosystems and human health.

An integrated One Health framework for holistic evaluation of risks from antifungal agents in a large-scale multi-city study

A new framework for retrospective mass spectral data mining for antifungal agents (AFs) and Wastewater-Based Epidemiology (WBE) was developed as part of One Health framework to tackle risks from AFs. A large scale, multi-city study was undertaken in South-West England. Key drivers of AFs in the catchment were identified with communal wastewater discharges being the main driver for human AFs (fluconazole, ketoconazole) and agricultural runoff being the main driver for pesticide AFs (prochloraz, prothioconazole and tebuconazole). Average WBE-estimated human used fluconazole and ketoconazole PNDIs (population normalised daily intake) exceeded 300 mg day-1 1000 inh-1 and 2000 mg day-1 1000 inh-1. This is much higher than PNDPs (population normalised daily prescriptions <40 mg day-1 1000 inh-1 and <80 mg day-1 1000 inh-1 for fluconazole and ketoconazole respectively). This was expected due to both prescription and over-the-counter usage, and both oral and topical applications. Pesticide AF, prothioconazole had PNDIs <40,000 mg day-1 1000 inh -1, which gave intake: 0.43, 0.26, 0.07 mg kg-1 in City A, B, and C, likely due to accounting for external/non-human sources. This is higher than the acceptable daily intake (ADI) of 0.01 mg kg-1bw day-1, which warrants further study. Intake per kg of body weight estimated using tebuconazole was 0.86, 1.39, 0.12, 0.13, and 2.7 mg kg-1 in City A-E respectively and is likely due to external/non-human sources. Intake calculated using its metabolite was 0.02 and 0.01 mg kg-1 in City B and C respectively, which aligned with ADI (0.03 mg kg-1bw day-1). The environmental risk assessment of AFs indicated low/medium risk from fluconazole, prochloraz, and tebuconazole, medium risk from epoxiconazole, prothioconazole's metabolite, and tebuconazole, and high risk for prothioconazole in river water. High risk was estimated from fluconazole, epoxiconazole, prothioconazole and its metabolite, tebuconazole, ketoconazole in wastewater samples, which is important during raw sewage discharge events via sewer overflows.

Assessment of the occurrence of 455 pharmaceutical compounds in sludge according to their physical and chemical properties: A review

Sludge agronomical reuse is of major interest due to the beneficial contribution of nutrients. However, it implies the introduction of unregulated pharmaceuticals into amended-soils and creates a controversial issue about sludge management. To limit their dissemination, it is essential to identify the compounds of interest and understand their attenuation mechanisms through the sludge processes. This paper summarizes the knowledge on 455 investigated pharmaceuticals among 32 therapeutical categories in amendable sludge matrices. It contributes to enlarging the list of commonly quantified compounds to 305 residues including 84 additional compounds compared to previous reviews. It highlights that sorption appears as the main mechanism controlling the occurrence of pharmaceuticals in sludge matrices and shows the considerable residual levels of pharmaceuticals reaching several mg/kg in dry weight. Antibiotics, stimulants, and antidepressants show the highest concentrations up to 232 mg/kg, while diuretics, anti-anxieties or anticoagulants present the lowest concentrations reaching up to 686 µg/kg. Collected data show the increase in investigated compounds as antifungals or antihistamines, and underline emerging categories like antidiabetics, antivirals, or antiarrhythmics. The in-depth analysis of the substantial database guides onto the pharmaceuticals that are the most likely to occur in these amendable matrices to assist future research.

Air assisted in situ deep eutectic solvent decomposition followed by the solidification of floating organic droplets-liquid-liquid microextraction method for extraction of azole antifungal drugs in biological samples prior to high-performance liquid chromatography

A free dispersive method, air-assisted in situ deep eutectic solvent decomposition followed by the solidification of floating organic droplets liquid-liquid microextraction was indicated in this study. This technique was utilized to simultaneously ascertain some azole antifungal drugs prior to high-performance liquid chromatography. In this research, a quasi-hydrophobic deep eutectic solvent was formed from tetrabutylammonium bromide and 1-dodecanol as an organic solvent at a 1:2 molar ratio. The synthesized deep decomposition in the sample solution caused in situ dispersion of extraction solvent and analytes. Air-assisted enhanced a dispersion condition in the sample solution. 1-dodecanol as a green option was replaced with typical extraction solvents providing the advantages of a suitable freezing point near room temperature and low density. The effect of important analytical parameters on the extraction recovery of analytes was assessed. Under these optimal conditions, the limits of detection and limits of quantitation determined were in the range of 0.5-2.8 μg L^-1 and 1.5-9 μg L^-1 , for water, urine and plasma samples, respectively. The Intra-day and inter-day relative standard deviations (RSD% n = 5) were calculated to be 2.9-4.6 % and 4.2-8.9 %, respectively. The results represented the effectiveness of the developed method for the extraction and determination of analytes in biological samples. This article is protected by copyright. All rights reserved.

Micellar electrokinetic chromatography in the determination of triazoles in fruit peel

Triazole fungicides (TAFs) are frequently used fungicides for various antifungal treatments of crops. Tre treatment is provided foliarly. However, some significant amount of TAFs may remain on/in fruits. We have developed a methodology for the determination of penconazole, tebuconazole and cyproconazole in tomato fruit peel. The extraction of TAFs was provided with chloroform (acidified with 0.1% acetic acid). In the electrokinetic chromatography, the mixed micellar pseudo-stationary phase was composed of anionic detergent sodium dodecyl sulphate (15 mM) and randomly highly sulphated gamma-cyclodextrin (17.5 mg/mL). The background electrolyte consisted of 100 mM phosphoric acid and 100 mM Tris in the mixed hydro-organic solvent water/methanol (80/20 v/v), apparent pH 4.8. Complete separation of penconazole, tebuconazole, and two diastereomers of cyproconazole with resolutions higher than 5.1 were achieved within a relatively short time of less than 17 min in the bare fused silica capillary of 425/500 mm total/effective lengths and 50/375 μm I.D./O.D. at separation voltage -15 kV (cathode at injection capillary end) and at constant capillary cassette temperature of 22°C. The TAFs were detected by a UV-spectrophotometric diode array detector set at 200 nm. The limits of detection and limits of quantification were in the range of 71-92 and 214-278 μg/kg of peel, respectively. Analyses of the peel extracts revealed that even 10 days after the last treatment, TAF concentrations were higher than the recommended maximum residue limits in both application ways, as individual as well as in the TAF binary or ternary mixtures.

A multi-residue chiral liquid chromatography coupled with tandem mass spectrometry method for analysis of antifungal agents and their metabolites in aqueous environmental matrices

The presence and fate of antifungal agents in the environment have hardly been investigated. This is despite the increased usage of antifungal agents and higher prevalence of antifungal resistance. Stereochemistry of antifungal agents has been largely overlooked due to lack of analytical methods enabling studies at the enantiomeric level. This paper introduces a new analytical method for combined separation of achiral and chiral antifungal agents and their metabolites with the utilization of chiral chromatography coupled with triple quadrupole tandem mass spectrometry to enable comprehensive profiling of wide-ranging antifungal agents and their metabolites in environmental matrices. The method showed very good linearity and range (r² > 0.997), method accuracy (61-143%) and precision (3-31%) as well as low (ng L^-1) MQLs for most analytes. The method was applied in selected environmental samples. The following analytes were quantified: fluconazole, terbinafine, N-desmethyl-carboxyterbinafine, tebuconazole, epoxiconazole, propiconazole and N-deacetyl ketoconazole. They were predominantly present in the aqueous environment (as opposed to wastewater) with sources linked with animal and plant protection rather than usage in humans. Interestingly, chiral fungicides quantified in river water were enriched with one enantiomer. This might have consequences in terms of their ecological effects which warrants further study.

Enantioseparation of ketoconazole and miconazole by capillary electrophoresis and a study on their inclusion interactions with β-cyclodextrin and derivatives

A chiral separation method coupled with capillary electrophoresis (CE) analysis for ketoconazole and miconazole enantiomers using chiral selectors such as β-cyclodextrin (β-CD) and hydroxypropyl-β-CD (HP-β-CD) was developed in this study, which included the optimisation, validation and application of the method on the antifungal cream samples. The formation of inclusion complex between the hosts (β-CD and HP-β-CD) and guests (ketoconazole and miconazole) were compared and analysed using ultraviolet-visible spectrophotometry, nuclear magnetic resonance (NMR) spectroscopy and molecular docking methods. Results from the study showed that in a concentration that ranged between 0.25 and 50 mg L^-1 , the linear calibration curves of each enantiomer had a high coefficient of regression (R² > 0.999), low limit of detection (0.075 mg L^-1 ) and low limit of quantification (0.25 mg L^-1 ). The relative standard deviation (RSD) of the intraday and interday analyses ranged from 0.79% to 8.01% and 3.30% to 11.43%, respectively, while the recoveries ranged from 82.0% to 105.7% (RSD < 7%, n = 3). The most probable structure of the inclusion complexes was proposed based on the findings from the molecular docking studies conducted using the PatchDock server.

Enantiomeric determination of econazole and sulconazole by electrokinetic chromatography using hydroxypropyl-β-cyclodextrin combined with ionic liquids based on L-lysine and L-glutamic acid

Two analytical methodologies based on the combined use of hydroxypropyl-β-cyclodextrin and two different amino acid-based chiral ionic liquids (tetrabutylammonium-L-lysine or tetrabutylammonium-L-glutamic acid) in electrokinetic chromatography were developed in this work to perform the enantioselective determination of econazole and sulconazole in pharmaceutical formulations. The influence of different experimental variables such as buffer concentration, applied voltage, nature and concentration of the ionic liquid, temperature and injection time, on the enantiomeric separation was investigated. The combination of hydroxypropyl-β-cyclodextrin and tetrabutylammonium-L-lysine under the optimized conditions enabled to achieve the enantiomeric determination of both drugs with high enantiomeric resolution (3.5 for econazole and 2.4 for sulconazole). The analytical characteristics of the developed methodologies were evaluated in terms of linearity, precision, LOD, LOQ and recovery showing good performance for the determination of both drugs which were successfully quantitated in pharmaceutical formulations. This work reports the first analytical methodology enabling the enantiomeric determination of sulconazole in pharmaceutical formulations.

Occurrence and risk assessment of azole antifungal drugs in water and wastewater

The occurrence of azole antifungals in the environment presents one of the emerging concerns due to their ecotoxicological threat as well as their potential contribution to the evolution of drug resistant fungi in the environment. In this study, the occurrence of eight commonly prescribed azole antifungal drugs was seasonally determined in influent and effluent water samples from three wastewater treatment plants and a drinking water treatment plant in South Africa. In addition, the risk quotient (RQ) method was employed to investigate the potential ecological and human health risks associated with their presence in the wastewater and/or drinking water. Clotrimazole, econazole, fluconazole, itraconazole, ketoconazole and miconazole were detected at least once in the water samples, while posaconazole and voriconazole were not detected in any of the samples for all seasons at which the samples were collected. Fluconazole was detected at higher frequency (about 96%) with a concentration up to 9959.0 ng L^-1. Clotrimazole had the second highest frequency of detection (about 33%) with a concentration up to 143.3 ng L^-1. Statistically significant temporal variation in clotrimazole (p < 0.05) and spatial variation in fluconazole (p < 0.05) were observed. In general, the preliminary ecological risk assessment based on risk quotient (RQ) calculation indicated that there is currently no high risk against aquatic organisms (Algae, Daphnia and Fish) related to the azole antifungals. Meanwhile, human health risk assessment demonstrated that fluconazole represented high risk in drinking water. Furthermore, risk estimates showed a potential for the detected concentrations of fluconazole and itraconazole in water samples to pose moderate to high risk for development of antifungal drug resistance. Some of the azole antifungal drugs are ubiquitous in the wastewater and future monitoring and validation studies should be conducted for those drugs that seem to pose human health and ecological risks.

Target quantification of azole antifungals and retrospective screening of other emerging pollutants in wastewater effluent using UHPLC -QTOF-MS

The information acquired by high resolution quadrupole-time of flight mass spectrometry (QTOF-MS) allows target analysis as well as retrospective screening for the presence of suspect or unknown emerging pollutants which were not included in the target analysis. Targeted quantification of eight azole antifungal drugs in wastewater effluent as well as new and relatively simple retrospective suspect and non-target screening strategy for emerging pollutants using UHPLC-QTOF-MS is described in this work. More than 300 (parent compounds and transformation products) and 150 accurate masses were included in the retrospective suspect and non-target screening, respectively. Tentative identification of suspects and unknowns was based on accurate masses, peak intensity, blank subtraction, isotopic pattern (mSigma value), compound annotation using data bases such as KEGG and CHEBI, and fragmentation pattern interpretation. In the targeted analysis, clotrimazole, fluconazole, itraconazole, ketoconazole and posaconazole were detected in the effluent wastewater sample, fluconazole being with highest average concentration (302.38 ng L^-1). The retrospective screening resulted in the detection of 27 compounds that had not been included in the target analysis. The suspect compounds tentatively identified included atazanavir, citalopram, climbazole, bezafibrate estradiol, desmethylvenlafaxine, losartan carboxylic acid and cetirizine, of which citalopram, estradiol and cetirizine were confirmed using a standard. Carbamazepine, atrazine, efavirenz, lopinavir, fexofenadine and 5-methylbenzotriazole were among the compounds detected following the non-targeted screening approach, of which carbamazepine was confirmed using a standard. Given the detection of the target antifungals in the effluent, the findings are a call for a wide assessment of their occurrence in aquatic environments and their role in ecotoxicology as well as in selection of drug resistant fungi. The findings of this work further highlights the practical benefits obtained for the identification of a broader range of emerging pollutants in the environment when retrospective screening is applied to high resolution and high accuracy mass spectrometric data.

Stability and toxicity studies for duloxetine and econazole on Spirodela polyrhiza using chiral capillary electrophoresis

Stability and toxicity studies for duloxetine and econazole were achieved using individual solutions and their mixtures. Stability of drugs racemates and enantiomers was investigated under abiotic and biotic conditions. Toxicity was evaluated for the first time on Spirodela polyrhiza. EC50 values were calculated for each individual drug and for their binary mixture. Real (not nominal) concentrations determined by Capillary Electrophoresis were employed in the calculations of toxicity parameters. The use of a 25 mM phosphate buffer (pH 3.0) with 1.5% S-β-CD as chiral selector at a temperature of 30 °C and a separation voltage of -20 kV enabled the simultaneous enantiomeric separation of duloxetine and econazole in 7.5 min with enantiomeric resolutions of 7.9 and 6.5, respectively. For individual solutions, decay percentages under abiotic conditions were higher for duloxetine (80%) than for econazole (60%), while in presence of Spirodela polyrhiza they increased for duloxetine but not for econazole. Econazole showed the highest decay percentages under abiotic or biotic conditions (100%) in binary mixtures. EC50 values for duloxetine and econazole enabled to include both drugs within the group of very toxic compounds although econazole showed a higher toxicity than duloxetine and the binary mixture.

Antibiotic distribution, risk assessment, and microbial diversity in river water and sediment in Hong Kong

For the past fewer years, environment antibiotic residues have got more and more attention. The occurrence and distribution of eight common antibiotics, belonging to five classes, were determined in both water and sediment of eleven rivers of Hong Kong. The target antibiotics were found to be widely distributed. Sulfamethoxazole (n.d.-79.9 ng/L), sulfadimidine (n.d.-29.9 ng/L), and ofloxacin (n.d.-75.5 ng/L) were the dominant antibiotics in river water, with detection rates of 84.6, 76.9, and 69.2%, respectively. Tetracycline (n.d.-9.8 ng/g) was the dominant antibiotic in sediment, with a detection rate of 60%. The concentrations of all antibiotics in river water of Hong Kong were lower than which in various rivers of Europe, North America and Australia, as well as the Pearl River Basin of China. All sediment sites exhibited significant bacterial diversity. Gammaproteobacteria (0.08-12.7%) and Flavobacteria (0.14-14.1%) were the dominant bacterial classes in all sediments. The bacterial compositions varied between sites; areas polluted with high levels of antibiotics had rich and highly diverse bacterial communities. The environmental risk assessment determined that the antibiotics in 73.1% of the samples posed ecological risks to algae, and two samples posed low risks to invertebrates. Ofloxacin was the main contributor of risk to aquatic organisms, while the antibiotics in 11.5% of the samples posed resistance selection risks. The occurrence and distribution of eight common antibiotics, belonging to five classes, were widely distributed in Hong Kong. Sulfamethoxazole, sulfadimidine, and ofloxacin were the dominant antibiotics in river waters, Tetracycline was the dominant antibiotic in sediment. Areas polluted with high levels of antibiotics had rich and highly diverse bacterial communities. Antibiotics in 73.1% of the samples posed ecological risks, while the antibiotics in 11.5% of the samples posed resistance selection risks.

Simultaneous enantiomeric analysis of eight pesticides in soils and river sediments by chiral liquid chromatography-tandem mass spectrometry

A rapid and sensitive multi-residue method was developed for the simultaneous quantification of eight chiral pesticides (including diniconazole, metalaxyl, paclobutrazol, epoxiconazole, myclobutanil, hexaconazole, napropamide and isocarbophos) at enantiomeric levels in environmental soils and sediments using chiral liquid chromatography-tandem mass spectrometry based on a combined pretreatment of matrix solid-phase dispersion and dispersive liquid-liquid microextraction (MSPD-DLLME). Under optimized conditions, 0.1 g of solid sample was dispersed with 0.4 g of C18-bonded silica sorbent, and 3 mL of methanol was used for eluting the analytes. The collected eluant was dried and then further purified by DLLME with 550 μL of dichloromethane and 960 μL of acetonitrile as extraction and disperser solvent, respectively. The established method was validated and found to be linear, precise, and accurate over the concentration range of 2-500 ng g^-1 for epoxiconazole, paclobutrazol and metalaxyl and 4-500 ng g^-1 for isocarbophos, hexaconazole, myclobutanil, diniconazole and napropamide. Recoveries of sixteen enantiomers varied from 87.0 to 104.1% and the relative standard deviations (RSD) were less than 10.1%. Method detection and quantification limits (MDLs and MQLs) varied from 0.22 to 1.54 ng g^-1 and from 0.91 to 4.00 ng g^-1, respectively. Finally, the method was successfully applied to analyze the enantiomeric composition of the eight chiral pesticides in environmental solid matrices, which will help better understand the behavior of individual enantiomer and make accurate risk assessment on the ecosystem.

Multi-residue enantiomeric analysis of 18 chiral pesticides in water, soil and river sediment using magnetic solid-phase extraction based on amino modified multiwalled carbon nanotubes and chiral liquid chromatography coupled with tandem mass spectrometry

This manuscript describes, for the first time, the multi-residue analysis of 18 chiral pesticides at enantiomeric levels in both environmental liquid (river water, influent and effluent wastewater) and solid matrices (agricultural soil, forestal soil and river sediment) based on magnetic solid-phase extraction (MSPE) and chiral liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Magnetic amino modified multiwalled carbon nanotubes (m-MWCNTs-NH₂) were prepared and firstly applied to adsorb pesticides from complex matrices. Response surface methodology (RSM) was applied to assist the multivariable optimization. The simultaneous enantioseparation of the chiral pesticides was performed on a Chiralpak IG column. Under the optimum conditions, the mean recoveries for pesticides enantiomers from the water matrices ranged from 81.1 to 106.3% with intra-day RSD of 2.1-11.9% and inter-day RSD of 2.6-12.7%; the mean recoveries for all enantiomers from the solid matrices ranged from 80.3 to 105.9% with intra-day RSD of 2.3-10.9% and inter-day RSD of 4.0-13.4%. Good linearity was achieved for all enantiomers with determination coefficients (r²) greater than 0.9912. Method quantification limits were below 2.04ng L^-1 in liquid matrices and below 0.50ng g^-1 in solid matrices. The developed method offered some advantages, such as simple operation, rapidity and high concentration factor. Therefore, it is suitable for monitoring the enantiomeric compositions of chiral pesticides in different environmental matrices.

Chiral Drug Analysis in Forensic Chemistry: An Overview

Many substances of forensic interest are chiral and available either as racemates or pure enantiomers. Application of chiral analysis in biological samples can be useful for the determination of legal or illicit drugs consumption or interpretation of unexpected toxicological effects. Chiral substances can also be found in environmental samples and revealed to be useful for determination of community drug usage (sewage epidemiology), identification of illicit drug manufacturing locations, illegal discharge of sewage and in environmental risk assessment. Thus, the purpose of this paper is to provide an overview of the application of chiral analysis in biological and environmental samples and their relevance in the forensic field. Most frequently analytical methods used to quantify the enantiomers are liquid and gas chromatography using both indirect, with enantiomerically pure derivatizing reagents, and direct methods recurring to chiral stationary phases.

Chiral separation and a molecular modeling study of eight azole antifungals on the cellulose tris(3,5-dichlorophenylcarbamate) chiral stationary phase

Four immobilized polysaccharide-based chiral stationary phases have been examined for their enantioselectivity on azole analytes using normal phase liquid chromatography.

A chiral enantioseparation generic strategy for anti-Alzheimer and antifungal drugs by short end injection capillary electrophoresis using an experimental design approach

The present study describes a generic strategy using capillary electrophoretic (CE) method for chiral enantioseparation of anti-Alzheimer drugs, namely, donepezil (DON), rivastigmine (RIV), and antifungal drugs, namely, ketoconazole (KET), Itraconazole (ITR), fluconazole (FLU), and sertaconazole (SRT) in which these drugs have different basic and acidic properties. Several modified cyclodextrins (CDs) were applied for enantioseparation of racemates such as highly sulfated α, γ CDs, hydroxyl propyl-β-CD, and Sulfobutyl ether-β-CD. The starting screening conditions consist of 50-mM phosphate-triethanolamine buffer at pH 2.5, an applied voltage of 15 kV, and a temperature of 25°C. The CE strategy implemented in the separation starts by screening prior to the optimization stage in which an experimental design is applied. The design of experiment (DOE) was based on a full factorial design of the crucial two factors (pH and %CD) at three levels, to make a total of nine (3² ) experiments with high, intermediate, and low values for both factors. Evaluation of the proposed strategy pointed out that best resolution was obtained at pH 2.5 for five racemates using low percentages of HS-γ-CD, while SBE-β-CD was the most successful chiral selector offering acceptable resolution for all the six racemates, with the best separation at low pH values and at higher %CD within 10-min runtime. Regression study showed that the linear model shows a significant lack of fit for all chiral selectors, anticipating that higher orders of the factors are most likely to be present in the equation with possible interactions.

Veterinary antibiotics in food, drinking water, and the urine of preschool children in Hong Kong

Due to the harmful effects of veterinary antibiotics (VAs) residues in food on children's health, urine samples from 31 preschool and primary school children were analyzed for 13 common VAs. Samples of raw and cooked pork, chicken, fish, milk and drinking water from the children's living areas were also analyzed for residual VAs. Urinalysis revealed one to four target antibiotics in 77.4% of the sample group, with concentrations as high as 0.36ng/mL. Norfloxacin and penicillin had the highest detection rates (48.4% and 35.5%, respectively), with median concentrations of 0.037 and 0.13ng/mL, respectively. The VA burden of children in HK was lower than that in Shanghai. Enrofloxacin, penicillin, and erythromycin were the most detected VAs in raw and cooked food. Only oxytetracycline was detected in terminal tap water, and none were detected in milk. Tetracycline and doxycycline hyclate were detected in organic eggs (up to 7.1ng/g) and regular eggs (up to 6.6ng/g), which were common in children's diets. Traditional Chinese cooking processes did not completely eliminate VAs, and the concentrations of some VAs increased, especially after frying and roasting. The estimated daily intake (EDI) results show that the contribution of dietary intake and that based on the urine concentrations of VAs were far below the acceptable daily intake (ADI). The EDIs from urine were significantly lower than those based on cooked foods. The highest level of achievement percentage (LAP) based on dietary consumption and urine concentrations were 39.7% and 1.79%, respectively, and thus current levels of exposure to VAs would not seem to pose a risk to children's health. However, harmful effects of residual VAs during developmental periods may occur with exposure to much lower doses than those considered harmful to adults, and further investigation of these emerging pollutants is urgently encouraged.

Stereoselective Analysis and Dissipation of Propiconazole in Wheat, Grapes, and Soil by Supercritical Fluid Chromatography-Tandem Mass Spectrometry

An efficient and sensitive chiral analytical method was established for the determination of propiconazole stereoisomers by supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS). Stereoisomeric separation was performed on a Chiralpak AD-3 column with CO₂/ethanol (93:7) as the mobile phase. The four propiconazole stereoisomers were well separated in 4.7 min with resolutions above 2.0. The specificity, linearity, matrix effects, accuracy, precision, and stability of the developed method were evaluated. The stereoselective dissipation of propiconazole in wheat straw, grape, and soil samples was investigated according to the proposed method. The results indicated that significant stereoselective degradation occurred in wheat straw and grapes, with preferential degradation of (-)-propiconazole A and (+)-propiconazole B in wheat straw and the opposite case in grapes. No enantioselectivity was observed in soil, although diastereoisomer A degraded more rapidly than diastereoisomer B. These results could contribute to a more accurate assessment of the environmental risk and food safety of propiconazole.

Enantiomeric Profiling of Chiral Pharmacologically Active Compounds in the Environment with the Usage of Chiral Liquid Chromatography Coupled with Tandem Mass Spectrometry

The issue of drug chirality is attracting increasing attention among the scientific community. The phenomenon of chirality has been overlooked in environmental research (environmental occurrence, fate and toxicity) despite the great impact that chiral pharmacologically active compounds (cPACs) can provoke on ecosystems. The aim of this paper is to introduce the topic of chirality and its implications in environmental contamination. Special attention has been paid to the most recent advances in chiral analysis based on liquid chromatography coupled with mass spectrometry and the most popular protein based chiral stationary phases. Several groups of cPACs of environmental relevance, such as illicit drugs, human and veterinary medicines were discussed. The increase in the number of papers published in the area of chiral environmental analysis indicates that researchers are actively pursuing new opportunities to provide better understanding of environmental impacts resulting from the enantiomerism of cPACs.

Occurrence and risk assessment of antibiotics in river water in Hong Kong

The occurrence and distribution of six typical antibiotics in the main rivers of Hong Kong were investigated using high-performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ES-MS/MS). The results revealed that the antibiotics were widely distributed in the area studied. Of the target antibiotics, ofloxacin was the most frequently detected in the rivers, with a detection rate of 69.6% and a median concentration of 0.7ng/L. Sulfadimidine (n.d-580.4ng/L) and doxycycline (n.d-82.2ng/L), with detection frequencies of 65.2% and 30.4%, respectively, were found at the same level as in rivers in North America, Spain, France, Australia, and in the Yangtze and Pearl Rivers of China, while the other target antibiotics were found at lower levels. According to the ratios of the measured environmental concentration to the predicted no-effect concentration, ofloxacin and doxycycline could present a medium to low ecological risk to algae, while sulfonamides posed no obvious ecological risk to the relevant aquatic organisms (algae, Daphnia magna, and fish). A high detection rate of antibiotics occurred in densely populated areas, revealing that population activities might be greatly contributing to the increasing levels of antibiotics in the area. Thus, the residues of antibiotics present in the waters of Hong Kong need to be closely monitored.

Spectral Sensitivity Measured with Electroretinogram Using a Constant Response Method

A new method is presented to determine the retinal spectral sensitivity function S(λ) using the electroretinogram (ERG). S(λ)s were assessed in three different species of myomorph rodents, Gerbils (Meriones unguiculatus), Wistar rats (Ratus norvegicus), and mice (Mus musculus). The method, called AC Constant Method, is based on a computerized automatic feedback system that adjusts light intensity to maintain a constant-response amplitude to a flickering stimulus throughout the spectrum, as it is scanned from 300 to 700 nm, and back. The results are presented as the reciprocal of the intensity at each wavelength required to maintain a constant peak to peak response amplitude. The resulting S(λ) had two peaks in all three rodent species, corresponding to ultraviolet and M cones, respectively: 359 nm and 511 nm for mice, 362 nm and 493 nm for gerbils, and 362 nm and 502 nm for rats. Results for mouse and gerbil were similar to literature reports of S(λ) functions obtained with other methods, confirming that the ERG associated to the AC Constant-Response Method was effective to obtain reliable S(λ) functions. In addition, due to its fast data collection time, the AC Constant Response Method has the advantage of keeping the eye in a constant light adapted state.

Occurrence, fate and ecological risk of five typical azole fungicides as therapeutic and personal care products in the environment: A review

Azole fungicides are widely used to treat fungal infection in human. After application, these chemicals may reach to the receiving environment via direct or indirect discharge of wastewaters, thus posing potential risks to non-target organisms. We aimed to review the occurrence, fate and toxicological effects of some representative household azole fungicides in the environment. Azole fungicides were widely detected in surface water and sediment of the aquatic environment due to their incomplete removal in wastewater treatment plants. These chemicals are found resistant to microbial degradation, but can undergo photolysis under UV irradiation. Due to different physiochemical properties, azole fungicides showed different environmental behaviors. The residues of azole fungicides could cause toxic effects on aquatic organisms such as algae and fish. The reported effects include regulation changes in expression of cytochrome P450-related genes and alteration in CYP450-regulated steroidogenesis causing endocrine disruption in fish. Further studies are essential to investigate the removal of azole fungicides by advanced treatment technologies, environmental fate such as natural photolysis, and toxic pathways in aquatic organisms.

Multi-residue enantiomeric analysis of human and veterinary pharmaceuticals and their metabolites in environmental samples by chiral liquid chromatography coupled with tandem mass spectrometry detection

Enantiomeric profiling of chiral pharmacologically active compounds (PACs) in the environment has hardly been investigated. This manuscript describes, for the first time, a multi-residue enantioselective method for the analysis of human and veterinary chiral PACs and their main metabolites from different therapeutic groups in complex environmental samples such as wastewater and river water. Several analytes targeted in this paper have not been analysed in the environment at enantiomeric level before. These are aminorex, carboxyibuprofen, carprofen, cephalexin, 3-N-dechloroethylifosfamide, 10,11-dihydro-10-hydroxycarbamazepine, dihydroketoprofen, fenoprofen, fexofenadine, flurbiprofen, 2-hydroxyibuprofen, ifosfamide, indoprofen, mandelic acid, 2-phenylpropionic acid, praziquantel and tetramisole. The method is based on chiral liquid chromatography utilising a chiral α1-acid glycoprotein column and tandem mass spectrometry detection. Excellent chromatographic separation of enantiomers (Rs≥1.0) was achieved for chloramphenicol, fexofenadine, ifosfamide, naproxen, tetramisole, ibuprofen and their metabolites: aminorex and dihydroketoprofen (three of four enantiomers), and partial separation (Rs = 0.7-1.0) was achieved for ketoprofen, praziquantel and the following metabolites: 3-N-dechloroethylifosfamide and 10,11-dihydro-10-hydroxycarbamazepine. The overall performance of the method was satisfactory for most of the compounds targeted. Method detection limits were at low nanogram per litre for surface water and effluent wastewater. Method intra-day precision was on average under 20% and sample pre-concentration using solid phase extraction yielded recoveries >70% for most of the analytes. This novel, selective and sensitive method has been applied for the quantification of chiral PACs in surface water and effluent wastewater providing excellent enantioresolution of multicomponent mixtures in complex environmental samples. It will help with better understanding of the role of individual enantiomers in the environment and will enable more accurate environmental risk assessment.

Chiral profiling of azole antifungals in municipal wastewater and recipient rivers of the Pearl River Delta, China

Enantiomeric compositions and fractions (EFs) of three chiral imidazole (econazole, ketoconazole, and miconazole) and one chiral triazole (tebuconazole) antifungals were investigated in wastewater, river water, and bed sediment of the Pearl River Delta, South China. The imidazole pharmaceuticals in the untreated wastewater were racemic to weakly nonracemic (EFs of 0.450-0.530) and showed weak enantioselectivity during treatment in the sewage treatment plant. The EFs of the dissolved azole antifungals were usually different from those of the sorbed azoles in the suspended particulate matter, suggesting different behaviors for the enantiomers of the chiral azole antifungals in the dissolved and particulate phases of the wastewater. The azole antifungals were widely present in the rivers. The bed sediment was a sink for the imidazole antifungals. The imidazoles were prevalently racemic, whereas tebuconazole was widely nonracemic in the rivers. Seasonal effects were observed on distribution and chirality of the azole antifungals. Concentrations of the azole antifungals in the river water were relatively higher in winter than in spring and summer while the EF of miconazole in the river water was higher in summer. The mechanism of enantiomeric behavior of the chiral azole antifungals in the environment warrants further research.

Pharmaceuticals and personal care products (PPCPs): a review on environmental contamination in China

Pharmaceuticals and personal care products (PPCPs) which contain diverse organic groups, such as antibiotics, hormones, antimicrobial agents, synthetic musks, etc., have raised significant concerns in recently years for their persistent input and potential threat to ecological environment and human health. China is a large country with high production and consumption of PPCPs for its economic development and population growth in recent years. This may result in PPCP contamination in different environmental media of China. This review summarizes the current contamination status of different environment media, including sewage, surface water, sludge, sediments, soil, and wild animals, in China by PPCPs. The human body burden and adverse effects derived from PPCPs are also evaluated. Based on this review, it has been concluded that more contamination information of aquatic environment and wildlife as well as human body burden of PPCPs in different areas of China is urgent. Studies about their environmental behavior and control technologies need to be conducted, and acute and chronic toxicities of different PPCP groups should be investigated for assessing their potential ecological and health risks.