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1.
A reliable multiclass method has been developed and validated for the determination of eight antibiotics from distinct classes (sulfonamides, macrolides, fluoroquinolones, tetracyclines, cephalosporins and dihydrofolate reductase inhibitors) in wastewater – influent and effluent – and surface water from Porto Alegre, Brazil. The pre-concentration and clean-up was conducted with a simple and fast protocol using solid-phase extraction allowing a 100-fold concentration factor. The proposed method was validated by using spiked blank wastewater samples in terms of linearity, repeatability, reproducibility, recovery, matrix effects and limits of detection and quantification. Recovery was obtained in the range of 66–149%. Method limit of quantification ranged between 1.6 and 61.7 ng L?1. Samples (n = 16) were taken from January to August 2011 in one wastewater treatment plant, which uses conventional biological treatment. Sulfamethoxazole and trimethoprim show higher concentration, ranging from >10 to <6500 ng L?1, whereas erythromycin presented the lower amount. Differences between influent and effluent profiles were discussed. Surface water samples (n = 8) were collected in Arroio Diluvio, in four sampling points, in February 2012. From the eight antibiotics analysed, five were detected: sulfamethoxazole, trimethoprim, azythromicyn, ciprofloxacin and norfloxacin, in a concentration range of 376–572 ng L?1, 27–94 ng L?1, 24–40 ng L?1, 16–66ng L?1 and 30–54 ng L?1, respectively.  相似文献   

2.
In this study, a practicable and effective analytical method based on solid-phase-extraction and reversed-phase liquid chromatography with fluorescence detection (SPE-LC-FLD) was developed and partially validated for routine analysis of eight FQs in wastewater at the trace level. Different SPE materials, pH conditions and eluents were modified to find an economic and effective SPE conditions. In our work, it is the first time that well-known commercially available SPE sorbent are compared to ‘generic’ cheap SPE sorbent. Aqueous samples (pH 2–3) were extracted using Anpel? MEP cartridges where they were subsequently eluted by 6?mL of 2% formic acid in MeOH. The aqueous extracts were analysed by gradient elution LC-FLD, whose initial mobile phase was composed of ACN and 10?mmol?L?1 tetrabutyl ammonium bromide (4/96, v/v, pH 3). The LODs and LOQs of the wastewater were as low as 0.32–2.12?ng?L?1 and 1.07–7.07?ng?L?1, respectively. The precisions of the overall method (RSD, n?=?3) using wastewater were below 10%. The method was used to quantify FQs in influents and effluents of several typical sewage treatment plants (STPs) in Shanghai. The extraction recoveries of 100?mL influent, 500?mL effluent and 500?mL of river water samples were between 88.6 and 102.6%, 79.2 and 109.2%, 80.0 and 105.5% and 87.4 and 99.4%, respectively. FQs of interest except sarafloxacin were identified in the influents, effluents and river waters with concentrations varying from 0.012–1.163?µg?L?1, 0.003–0.291?µg?L?1, and 0.002–0.040?µg?L?1, respectively. The method can serve as a tool to obtain detailed information on occurrence, behaviour and fate of FQs in the aquatic environment. Occurrence of FQs detected in summer is higher than in spring at STPs, and those detected in the suburban area are less than those in the urban area. Complete removal of FQs is not achieved from the STPs, indicating domestic wastewater and STP discharge is the source of FQs in the surface water.  相似文献   

3.
A sorbent L-cysteine grafted silica gel has been evaluated for separation and enrichment of dissolved inorganic i-Hg(II) and methylmercury CH3Hg(I) from surface waters at sub-μg L−1 concentrations. Chemical parameters for mercury species enrichment and separation have been optimized. Analytical schemes for the determination of Hg species, using selective column solid phase extraction (SPE) with continuous flow chemical vapor generation atomic absorption spectrometry (CF-CVG-AAS) or inductively coupled plasma-mass spectrometry (ICP-MS) were developed. Possibilities for on-site SPE enrichment were demonstrated as well. The limits of quantification were 1.5 and 5 ng L−1 for dissolved i-Hg(II) and CH3Hg(I) by CF-CVG-AAS and 1 and 2.5 ng L−1 by ICP-MS with relative standard deviations between 7–12% and 7–14%, respectively. The chemically modified SPE sorbent has demonstrated high regeneration ability, chemical and mechanical stability, acceptable capacity and good enrichment factors. Results for total dissolved mercury were in reasonable agreement with those from independent analyses by direct ICP-MS determinations for river waters and for estuarine water certified reference material.   相似文献   

4.
A highly efficient ultrasonic-assisted dispersive liquid–liquid microextraction (UA-DLLME) procedure coupled with gas chromatography–mass spectrometry was developed for simultaneous analysis of multiclass herbicides with endocrine-disrupting properties in environmental water samples. The parameters affecting the method’s extraction efficiency, such as the types and volumes of the extractant and dispersive solvents, sample pH, and salt concentration, were systematically optimized by response surface methodology based on central composite design to achieve excellent recoveries for multiclass herbicides. The final UA-DLLME protocol involved 115.6 µL of chloroform (extractant), 861.5 µL of ethanol (dispersive solvent), 5.0 mL of water samples, pH 10.0, and 4.3% NaCl solution. The performance of the developed UA-DLLME was compared with that of conventional solid-phase extraction (SPE). Under optimal extraction conditions, UA-DLLME exhibited a higher enrichment factor and greater sensitivity than SPE, with limits of detection and limits of quantification of 0.004–0.024 and 0.013–0.079 µg L?1, respectively, for seawater samples. The accuracy and precision of UA-DLLME were satisfactory for seawater samples spiked at three levels (0.2, 2.5, and 5.0 µg L?1). Average recoveries ranging from 82.3 to 101.8% were achieved, with relative standard deviations lower than 12.8%. The proposed analytical method was successfully applied to the simultaneous determination and quantification of 17 herbicides in environmental river and seawater samples.  相似文献   

5.
A gas chromatography–tandem mass spectrometry (GC–MS/MS) method has been developed for the determination of selected pharmaceutical residues (carbamazepine, salicylic acid, clofibric acid, ibuprofen, 2-hydroxy-ibuprofen, fenoprofen, naproxen, ketoprofen, diclofenac, and triclosan) in sewage influent and roughly primary-treated effluent. The method involved solid-phase extraction (SPE) with polymeric sorbents, and two SPE cartridges were compared for the extraction and elution of the targeted compounds in complex matrices. A successful chemical derivatization of carbamazepine and acidic compounds using N,O-bis(trimethylsilyl) trifluoroacetamide +10% trimethylchlorosilane is also described. The quantification limits of the analytical procedure ranged from 30 to 60?ng?L?1 for 500?mL of wastewater. The best recovery rates (72–102%) in spiked effluent samples were obtained with Phenomenex Strata-X? cartridges. Detection limits (S/N?=?3) were estimated at between 1 and 18?ng?L?1. The reported GC–MS/MS method significantly reduces the strong matrix effects encountered with more expensive LC-MS/MS techniques. Application of the developed method showed that most selected analytes were detected at concentrations ranging from low µg?L?1 to trace level ng?L?1 in Montreal's wastewater treatment plant effluent and influent, as well as in the receiving waters at more than 8?km downstream of the effluent outfall. The rugged alternative analytical method is suitable for the simultaneous analysis of carbamazepine and pharmaceutical acidic residues in wastewater samples from influents and effluents that have undergone rough primary treatment.  相似文献   

6.
A highly sensitive method was developed for the analysis of short‐chain perfluorinated alkyl acids (PFAAs) in serum samples using solid‐phase extraction (SPE) coupled with ion chromatography–electrospray ionization–mass spectrometry. The synthesized amino‐functionalized graphene oxide nanocomposites were used as an SPE sorbent for the enrichment of trace analytes and purification of samples. They exhibited high selectivity to polar compounds. The suppressor was employed to remove counterions and reduce background signals of mobile phase. These two crucial steps could effectively eliminate matrix effects and enhance analytical sensitivity. The lowest limits of quantification were 2.0 μg L−1 for perfluorobutanoic acid and perfluorovaleric acid, 1.0 μg L−1 for perfluorocaproic acid and 0.50 μg L−1 for perfluorobutane sulfonic acid, respectively. The procedure was successfully applied for determination of trace PFAAs in 25 serum samples. Mean recoveries ranged from 86.3 to 101.4% with relative standard deviations of 1.6–6.8%. The method allowed an excellent separation and quantification of short‐chain PFAAs that were difficult to analyze by conventional chromatography.  相似文献   

7.
A simple, reliable and novel solid phase extraction procedure using the Empore? chelating disk has been developed for determination of Tl(I) and Tl(III) in environmental water samples by electrothermal atomic absorption spectrometry (ETAAS). The influence of humic acids on separation/preconcentration of thallium species with the Empore? chelating disk is investigated. The preconcentration factor and detection limit are 500 and 5?ng?L?1, respectively. The recoveries are in the range 93–103% for mineral, pond, sea, snowmelt, waste waters at 28–500?ng?L?1 Tl and in the range 82–112% for river waters at 18–28?ng?L?1 Tl.  相似文献   

8.
9.
In this study, silica@chitosan-glutaraldehyde (Si@Cs-G) was synthesized as a novel adsorbent for extraction of Penicillin G (PG) from the synthetic and real samples followed by HPLC determination. The synthesized adsorbents were characterized by the scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM) and nitrogen adsorption–desorption techniques. The factors influencing the extraction efficiency including pH, sorbent dose, extraction time, extraction solvent type and its volume were investigated and optimized.Under the optimal conditions (sorbent dosage: 25 mg, desorption solvent (acetonitrile) with volume of 0.75 mL; pH: 6 and extraction time: 50 min), the Si@Cs-G demonstrated high efficiency and linearity (R2 > 0.999) with the concentration of penicillin G ranging from 1 to 300 μg L−1. Extraction recovery in synthetic samples was 98.977%, with LOD = 0.493 μg L−1, LOQ = 1.638 μg L−1 and RSD < 1.953%. The method was successfully applied for determination of PG in real water samples (tap, river, lake and well water) and wastewater samples (SH and SHB hospital effluent). The obtained relative recoveries were in the range of 91.31% -123.27% with RSD less than 6.34% for all the real samples. The dominant mechanism in the PG adsorption process was involved in the π-π interaction, hydrogen bonding, and electrostatic interaction.  相似文献   

10.

Zeolite NaY modified with cetyltrimethylammonium bromide (CTAB) was considered for extraction/preconcentration of carbamate pesticides using an on-line SPE-HPLC system. The simultaneous determination of carbamate pesticides, including aldicarb, carbofuran, carbaryl, isoprocarb, methiocarb and promecarb, was performed by HPLC–UV using a LichroCART RP-18 column with gradient elution of methanol and 0.1 % acetic acid. The sorbent presented admicelles of CTAB on its surfaces and exhibited a sorption capacity of 180–18,600 mg kg−1 sorbent, which could be re-modified for at least five extraction cycles. The quantitative retention of target pesticides on the admicellar sorbent involved hydrophobic and π-cation interaction, while pesticides were eluted from the admicellar SPE column using only 750 μL of methanol. LODs and LOQs of the proposed method were 0.005–140 and 0.02–600 μg L−1, respectively. The analytes were effectively concentrated with the enrichment factors between 5 and 551. The developed on-line admicellar SPE-HPLC system was successfully applied to the determination of carbamate pesticides in ten environmental water samples from different sources. Recoveries of spiked samples at a concentration of 0.1–5 mg L−1 ranged from 77 to 111 %.

  相似文献   

11.
A fully automated method consisting of microextraction by packed sorbent (MEPS) coupled directly to programmed temperature vaporizer–gas chromatography–mass spectrometry (PTV–GC–MS) has been developed to determine the 12 chlorobenzene congeners (chlorobenzene; 1,2-, 1,3-, and 1,4-dichlorobenzene; 1,2,3-, 1,2,4-, and 1,3,5-trichlorobenzene; 1,2,3,4-, 1,2,3,5-, and 1,2,4,5-tetrachlorobenzene; pentachlorobenzene; and hexachlorobenzene) in water samples. The effects of the variables on MEPS extraction, using a C18 sorbent, and the instrumental PTV conditions were studied. The internal standard 1,4-dichlorobenzene d4 was used as a surrogate. The proposed method afforded good reproducibility, with relative standard deviations (RSD %) lower than 12 %. The limits of detection varied between 0.0003 μg L?1 for 1,2,3,4-tetrachlorobenzene and 0.07 μg L?1 for 1,3- and 1,4-dichlorobenzene, while those of quantification varied between 0.001 μg L?1 and 0.2 μg L?1 for the same compounds. Accuracy of the proposed method was confirmed by applying it to the determination of chlorobenzenes in different spiked water samples, including river, reservoir, and effluent wastewater.
Figure
Experimental setup for automated MEPS methodology  相似文献   

12.
ABSTRACT

In this work, a novel layered sorbent for microextraction by packed sorbent (MEPS) was introduced, which has been prepared by coating graphene oxide/polyamide (GO/PA) nanocomposite (NC) onto cellulose paper through solvent exchange method. Scanning electron microscopy (SEM) was applied to investigate the surface characteristic and morphology of PA and GO/PA NC coated on cellulose paper. The prepared MEPS device was used for extraction of organophosphorous pesticides (OPPs) including chlorpyrifos, fenthion, fenithrothion, ethion, edifenphos and phosalone in environmental aqueous samples followed by detection using gas chromatography-flame ionisation detector (GC-FID). Important parameters affecting the MEPS method including pH of sample solution, extraction draw-discard cycles, sorbent layers, desorption solvent volume and desorption draw-eject number were studied and optimised using central composite design (CCD). Based on the method validation, limits of detection (LODs) were in the range of 0.2–1 µg L?1. The calibration graphs for chlorpyrifos, fenthion and edifenphos are linear in the concentration range of 1 to 500 µg L?1; for ethion and phosalone are linear in the range of 1–1000 µg L?1 and for fenithrothion is linear in the range of 3–1000 µg L?1. The method precision (RSD %) with six replicates determinations was in the range of 3 to 9.4 % and 3.9 to 11.9% for distilled water and spiked river water sample, respectively, at the concentration level of 300 µg L?1 . The developed method was applied successfully to determine OPP compounds in river, dam and tap water samples; accordingly, the relative recoveries (RR%) were obtained in the range of 77.8 to 113.3%.  相似文献   

13.
A high-performance liquid chromatography separation coupled with mass spectrometry via an electrospray interface is proposed for the determination of the hydroxylated derivatives of polycyclic aromatic hydrocarbons (OH-PAHs) in treated and untreated wastewaters and suspended solids from sewage treatment plants (STPs). The developed SPE procedure was applied to spiked wastewater samples, with recovery yields (1000?mL; 100?ng?L?1 spiking level) in the 65–87% (RSD: 6–12%) range for the selected OH-PAHs. The limits of detections ranged between 0.3 and 3.2?ng?L?1, depending on the selected compound and on the investigated matrix. The proposed method was applied to the determination of the selected analytes in real samples from a sewage-treatment plant (STP). The investigated OH-PAHs were detected mainly in the particulate fraction. The exhibited mean concentrations of positive samples (as the sum of dissolved and particulate matter) in the STP final effluent ranged from 15 to 68?ng?L?1.  相似文献   

14.
Steroid hormones are a diverse group of natural and synthetic compounds. Their wide use in human and veterinary medicine results in their continual introduction into the environment. In recent years, environmental concern over steroids that act as endocrine disruptors has increased because of their adverse effects on organisms or their progeny. Moreover, as these compounds are not totally removed from sewage in wastewater treatment plants, they can reach the aquatic environment and persist due to their physicochemical characteristics.For this reason, a major trend in analytical chemistry is the development of rapid and efficient procedures for the extraction, determination and quantification of steroid hormones in environmental samples. Over the past few decades, the significant expansion of liquid chromatography technology utilizing mass spectrometry detection has led to applications with increased selectivity and sensitivity. Optimized extraction and microextraction techniques combined to these liquid chromatography techniques have lowered detection and quantification limits to the ng L−1–μg L−1 range, which is the concentration of steroid hormones in liquid, solid and biota samples.In this paper, the state-of-the-art techniques for the analysis of steroid hormones focused mainly in based liquid chromatography methods in liquid and aquatic solid and biota samples are reviewed. Handling, storage, extraction and detection methodologies are reviewed and compared for all families of steroid hormones.  相似文献   

15.
This study investigated for the first time the occurrence of selected synthetic hormones including 17α-ethinylestradiol, levonorgestrel, norethindrone and cyproterone acetate in Malaysian tropical waters. Samples were collected from the effluents of five sewage treatment plants (STPs) and at seven stations along the Langat River in Selangor, Malaysia, and its main tributaries. Samples were extracted by solid phase extraction (SPE) and analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). In Langat river samples, only levonorgestrel and cyproterone acetate were found at 50% and 3.3% frequency. The concentrations detected for levonorgestrel ranged from less than the method detection limit (<MDL) to 213?ng?L?1 and from?<?MDL to 76?ng?L?1 for cyproterone acetate. For the STP effluent samples, levonorgestrel was <MDL in all samples and the concentrations detected were in the range?<?MDL – 262?ng?L?1 for cyproterone acetate,?<?MDL ?11336?ng?L?1 for norethindrone and?<?MDL – 1898?ng?L?1 for 17α-ethinylestradiol.  相似文献   

16.
This study features the simultaneous extraction and quantification of 18 pharmaceuticals and personal care products (PPCPs). This is a pioneering method for the quantification of acetaminophen, sulfamethoxazole, diclofenac, atenolol, metoprolol, diethyltoluamide and oxybenzone in atmospheric pressure chemical ionisation mode. The method was validated for high repeatability and reproducibility with relative standard deviations less than 10%. Instrument quantification limits for PPCPs were within the range of 0.05–1.0 µg L?1, and the method quantification limits (MQLs) for ultrapure water were within the range of 0.3–15 ng L?1. All samples were extracted using Oasis© hydrophilic–lipophilic balanced cartridges with optimised sample size and extraction conditions. Good accuracy was demonstrated, with solid-phase extraction recoveries above 80% for most PPCPs. In environmental matrices, the MQLs for river water, sewage treatment plant (STP) effluent and STP influent were 4–25, 10–153 and 38–386.5, respectively. The method was successfully applied to investigate occurrences of persistent PPCPs in Malaysian river and sewage samples.  相似文献   

17.
This is the first report on the analytical application of multiwalled carbon nanotubes (MWCNTs) as solid-phase extraction (SPE) sorbents for determination in surface waters, at the nanograms per litre level, of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), the two predominant contaminants among the perfluorinated compounds detected. After the preconcentration step, the quantification was achieved by ultraperformance liquid chromatography–electrospray ionization mass spectrometry. To increase the extraction efficiency towards these amphiphilic compounds, MWCNTs were derivatized with amino-terminated alkyl chains, thus producing a mixed-mode material (MWCNT-R-NH2) combining hydrophobic affinity and anion-exchange properties. Experiments with distilled, tap and river water (pH 3) spiked at different concentrations (10, 15, 30, 100, 200 and 500 ng L-1) provided absolute recoveries in the range 71–102 % (n?=?3, relative standard deviations less than 10 %). Analytes were eluted in a single fraction with 6 mL methanol (3?×?10-4 M NaOH). The within-laboratory reproducibility of the MWCNT-R-NH2 SPE sorbent was evaluated with raw river water, and relative standard deviations less than 15 % were obtained (n?=?4). Preconcentration factors up to 125 (500-mL sample) made it possible to quantify PFOA and PFOS at low nanograms per litre levels in naturally contaminated river water. The method quantification limits of 10 ng L-1 for PFOA and 15 ng L-1 for PFOS were well below the advisory levels for drinking and surface waters. Comparison with non-derivatized MWCNTs highlighted the role of functionalization in improving the adsorption affinity towards these contaminants. MWCNT-R-NH2 maintained their extraction capability for at least eight repeated adsorption/desorption cycles.  相似文献   

18.
A sensitive and highly selective method for the simultaneous determination of sulfonamides, macrolides, fluoroquinolones and trimethoprim in wastewater and river water has been developed. Samples were enriched by solid-phase extraction and analysed by reversed-phase liquid chromatography coupled to electrospray ionisation tandem mass spectrometry. Several surrogate standards were used for quantification purposes. Absolute recoveries of individual antimicrobials were between 49 and 133% with RSD between 1 and 18% in all investigated matrices. Detection limits in low ng L?1 range were achieved. The method was successfully applied to the analysis of raw municipal wastewater, wastewater effluents and river waters.  相似文献   

19.
《Electroanalysis》2018,30(9):2176-2184
The contamination of water and wastewater by emerging pollutants, due to the anthropogenic activities, are an environmental problem that generates several negative impacts. In this range of species, steroids have gaining notoriety because their action of endocrine‐disruption. In this work, they are called estrogenic phenolic compounds (EPCs): estrone (E1), estradiol (E2), ethinyl estradiol (EE2) and estriol (E3), for determination using an electrochemical sensor based on reduced graphene oxide (rGO) and molecularly imprinted polymer (MIP). The analytical method developed, allied with the experimental and operational optimizations, proved to be effective for the total quantification of the EPCs in river water. The method shows sensitivity of 1.12 μA/μmol L−1, detection limit of 26.8 nmol L−1 and linear range of 0.16–15 μmol L−1. The similar electrochemical behavior of the four compounds studied (E1, E2, EE2 and E3) and the efficiency of the modified composite (rGO, MIP) in the fabrication of the sensor resulted in high electrical conductivity and selective adsorptivity, respectively.  相似文献   

20.
A sensitive and robust method using solid-phase extraction and ultrasonic extraction for preconcentration followed by ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS–MS) has been developed for determination of 19 biocides: eight azole fungicides (climbazole, clotrimazole, ketoconazole, miconazole, fluconazole, itraconazole, thiabendazole, and carbendazim), two insect repellents (N,N-diethyl-3-methylbenzamide (DEET), and icaridin (also known as picaridin)), three isothiazolinone antifouling agents (1,2-benzisothiazolinone (BIT), 2-n-octyl-4-isothiazolinone (OIT), and 4,5-dichloro-2-n-octyl-isothiazolinone (DCOIT)), four paraben preservatives (methylparaben, ethylparaben, propylparaben, and butylparaben), and two disinfectants (triclosan and triclocarban) in surface water, wastewater, sediment, sludge, and soil. Recovery of the target compounds from surface water, influent, effluent, sediment, sludge, and soil was mostly in the range 70–120?%, with corresponding method quantification limits ranging from 0.01 to 0.31?ng?L?1, 0.07 to 7.48?ng?L?1, 0.01 to 3.90?ng?L?1, 0.01 to 0.45?ng?g?1, 0.01 to 6.37?ng?g?1, and 0.01 to 0.73?ng?g?1, respectively. Carbendazim, climbazole, clotrimazole, methylparaben, miconazole, triclocarban, and triclosan were detected at low ng?L?1 (or ng?g?1) levels in surface water, sediment, and sludge-amended soil. Fifteen target compounds were found in influent samples, at concentrations ranging between 0.4 (thiabendazole) and 372?ng?L?1 (methylparaben). Fifteen target compounds were found in effluent samples, at concentrations ranging between 0.4 (thiabendazole) and 114?ng?L?1 (carbendazim). Ten target compounds were found in dewatered sludge samples, at concentrations ranging between 1.1 (DEET) and 887?ng?g?1 (triclocarban).  相似文献   

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