The Ultratrace Determination of Fluoroquinolones in River Water Samples by an Online Solid-Phase Extraction Method Using a Molecularly Imprinted Polymer as a Selective Sorbent.

Fluoroquinolones (FQs) are broad-spectrum antibiotics widely used to treat animal and human infections. The use of FQs in these activities has increased the presence of antibiotics in wastewater and food, triggering antimicrobial resistance, which has severe consequences for human health. The detection of antibiotics residues in water and food samples has attracted much attention. Herein, we report the development of a highly sensitive online solid-phase extraction methodology based on a selective molecularly imprinted polymer (MIP) and fluorescent detection (HPLC-FLD) for the determination of FQs in water at low ng L−1 level concentration. Under the optimal conditions, good linearity was obtained ranging from 0.7 to 666 ng L−1 for 7 FQs, achieving limits of detection (LOD) in the low ng L−1 level and excellent precision. Recoveries ranged between 54 and 118% (RSD < 17%) for all the FQs tested. The method was applied to determining FQs in river water. These results demonstrated that the developed method is highly sensitive and selective.

Removal of low-calorie sweeteners at five Brazilian wastewater treatment plants and their occurrence in surface water.

The consumption of low-calorie sweeteners (LCSs) such as acesulfame (ACE), sucralose (SUC), saccharin (SAC), cyclamate (CYC), aspartame (ASP), neotame (NEO), and stevioside (STV) is increasing worldwide to meet the demand for reduced-calorie foods and beverages. However, there are no consumption data available in Brazil, as well as their concentration in sewage and removal on wastewater treatment plants (WWTPs). In the present study, ACE, SUC, SAC, CYC, ASP, NEO, and STV were assessed at five WWTPs located in the metropolitan region of Campinas (São Paulo State, Brazil), in operation with different treatment processes. Surface water was also analyzed. Analyses were carried out by on-line solid-phase extraction ultra-high performance liquid chromatography-tandem mass spectrometry. The major points are the following: LCS concentrations in the influents ranged from 0.25 to 189 µg L-1 and followed the order CYC > ACE > SAC > SUC. NEO, ASP, and STV were not detected at any sampling site. Sweetener concentrations in the WWTP outputs differed mainly due to the different treatment setups employed. CYC and SAC were completely removed by biodegradation-based processes, while ACE removal was favored by the anaerobic-anoxic-aerobic process. SUC presented the highest concentration in the treated sewage, even at the WWTP operating with ultrafiltration membranes and therefore could be a marker compound for evaluation of the efficiency of removal of contaminants in WWTPs. Risk quotient estimation, using the PNEC and MEC values, indicated that the levels of the LCS reported here were harmless to the biota. The consumption of ACE, CYC, SAC, and SUC was estimated to be 2634 t year-1.

Tracking the occurrence of psychotropic pharmaceuticals in Brazilian wastewater treatment plants and surface water, with assessment of environmental risks.

According to the World Health Organization, >360 million people worldwide suffer from mental diseases such as depression, anxiety, or bipolar disorder, for which psychotropic drugs are frequently prescribed. Despite being highly metabolized in the human organism, non-metabolized portions of these drugs are excreted, subsequently reaching wastewater treatment plants (WWTPs), where they may be incompletely removed during treatment, leading to the contamination of surface waters. In this work, ten psychotropic drugs widely consumed in Brazil (alprazolam, amitriptyline, bupropion, carbamazepine, clonazepam, escitalopram, fluoxetine, nortriptyline, sertraline, and trazadone) were monitored at five WWTPs located in the metropolitan region of Campinas (São Paulo State, Brazil). The drugs were determined in the influents, at different stages of the treatments, and in the effluents. Surface waters from the Atibaia River and the Anhumas Creek were also monitored. Quantitation of the pharmaceuticals was carried out by online solid-phase extraction coupled with ultra-high performance liquid chromatography and tandem mass spectrometry. The method was validated and presented a limit of quantitation of 50 ng L-1 for all the drugs assessed. Six of the substances monitored were quantified in the samples collected from the different treatment processes employed at the WWTPs. These technologies were unable to act as barriers for these psychotropics drugs. The concentrations ranged from 50 to 3000 ng L-1 in the WWTP effluents, while the main contaminants were found in surface waters at concentrations from 25 to 3530 ng L-1. The levels of the psychotropic detected in this work did not appear to present risks to the aquatic biota.

Prostaglandins E2 and F2α levels in human menstrual fluid by online Solid Phase Extraction coupled to Liquid Chromatography tandem Mass Spectrometry (SPE-LC-MS/MS).

This paper reports an online SPE-LC-MS/MS method for the simultaneous quantification of prostaglandins (PGE2 and PGF2α) in menstrual fluid samples. To meet this goal human peripheral serum was used as surrogate matrix. The analytes were trapped on an OASIS HLB cartridge for 3 min, for sample cleanup and enrichment, and then transferred during only 42 s to an HSS T3 C18 analytical column, for separation and analysis. Prostaglandins (PGs) were detected by selected reaction monitoring in negative ion mode, PGE2 (m/z 351 → 315) and PGF2α (m/z 353 → 193) using isotope-labeled internal standard (PGE2-d4, m/z 355 → 319). The concentration linear range was of 10.34-1.034 ng mL-1 and the lower limit of quantification (LLOQ) was 10.34 ng mL-1 for both PGs. Validation parameters were successfully assessed according to the European Medicines Agency guideline (EMA), also comprising the FDA normative. The method showed no matrix effect and process efficiency around 100%, in addition to only 15 min of analysis time with lower solvent consumption. The method application was carried out using two menstrual fluid sample groups: control (n = 15) and treatment group (n = 7; samples from women that used Tahiti lemon juice). The PGF2α levels were found to be higher in treated group than in control group (p ≤ 0.05), denoting an effect of the intake of Tahiti lemon juice on the menstrual inflammatory process. The on-line method herein reported could be useful for the analysis of PGs from large research studies.

Benzimidazoles in wastewater: Analytical method development, monitoring and degradation by photolysis and ozonation.

Pharmaceutical residues are constantly released into natural waters, mainly from wastewater treatment plants (WWTPs) whose processes are unable to completely eliminate them. Among these drugs, the occurrence of benzimidazoles, a class of antiparasitics for human and veterinary use, has been reported in WWTP effluents and surface waters. In this study, an SPE-UHPLC-MS/MS method was developed and optimized for extraction and quantitation of benzimidazoles in influents and effluents of a local WWTP and in hospital wastewater. The extraction procedure was optimized using response surface methodology (Box-Behnken design) and the optimal parameters were as follows: 2.0 mL of loading solvent consisting of a mixture of water:methanol (95:5, v/v) and temperature at 43 °C. In hospital wastewater, albendazole (ABZ) and its principal metabolite ricobendazole (RBZ) were the main benzimidazole-related contaminants and were found at concentrations of up to 3810 and 3894 ng L-1, respectively. The WWTP system was able to remove from 46% to 95% of the ABZ quantified in the influent, discharging an effluent with 16-441 ng L-1 of ABZ. The concentrations of other benzimidazoles and metabolites in the WWTP effluents remained below 350 ng L-1. WWTP effluents fortified with 50 µg L-1 of ABZ required 26.7 mgO3 L-1 to remove ABZ and RBZ. After ozonation, the COD and BOD5 of the effluents were reduced by 27%. Photolysis by UVA radiation was not effective to remove ABZ and FBZ from the effluent samples.

Online fully automated SPE-HPLC-MS/MS determination of ceftiofur in bovine milk samples employing a silica-anchored ionic liquid as sorbent.

Solid-phase extraction coupled online with high performance liquid chromatography and tandem mass spectrometry was successfully applied to determine low concentrations of ceftiofur antibiotic in bovine milk samples. A silica-anchored ionic liquid was applied as sorbent material to be used as extraction phase in the proposed online system. The material was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. In order to improve the system reproducibility, the following experimental parameters were optimized: organic solvent percentage, time and sample loading flow rate. Subsequently, the method was validated presenting satisfactory results as adequate selectivity, good linearity and correlation coefficient higher than 0.98. The limit of detection and quantification were 0.1 and 0.7 µg/L, respectively. The precision of the methodology was evaluated as repeatability and intermediate precision, with relative standard deviation values lower than 15%. The accuracy of the method ranged from 72.8 to 137% and the minimum and maximum recovery values were 73.4 and 111.3%, respectively. After the validation, seven milk samples were analyzed and although ceftiofur was not detected in any of them the method was demonstrated to be efficient when applied to the analysis of milk samples fortified with the pollutant of interest.