RESUMO
In the present study, a homemade mixed-mode ion-exchange sorbent based on silica with embedded graphene microparticles is applied for the selective extraction of 2-aminobenzothiazole (NH2BT) followed by determination through liquid chromatography coupled to high-resolution mass spectrometry. The sorbent was evaluated for the solid-phase extraction of NH2BT from environmental water samples (river, effluent wastewater, and influent wastewater), and NH2BT was strongly retained through the selective cation-exchange interactions. Therefore, the inclusion of a clean-up step of 7 mL of methanol provided good selectivity for the extraction of NH2BT. The apparent recoveries obtained for environmental water samples ranged from 62 to 69% and the matrix effect from -1 to -14%. The sorbent was also evaluated in the clean-up step of the organic extract for the extraction of NH2BT from organic extracts of indoor dust samples (10 mL of ethyl acetate from pressurized liquid extraction) and fish (10 mL of acetonitrile from QuEChERS extraction). The organic extracts were acidified (adding a 0.1% of formic acid) to promote the cation-exchange interactions between the sorbent and the analyte. The apparent recoveries for fish samples ranged from 22 to 36% depending on the species. In the case of indoor dust samples, the recovery was 41%. It should be highlighted the low matrix effect encountered in such complex samples, with values ranging from -7 to 5% for fish and dust samples. Finally, various samples were analyzed. The concentration in river samples ranged from 31 to 136 ng/L; in effluent wastewater samples, from 55 to 191 ng/L; in influent wastewater samples, from 131 to 549 ng/L; in fish samples, from 14 to 57 ng/g dried weight; and in indoor dust samples, from Assuntos
Espectrometria de Massas em Tandem
, Poluentes Químicos da Água
, Animais
, Espectrometria de Massas em Tandem/métodos
, Águas Residuárias
, Água/análise
, Poeira/análise
, Poluentes Químicos da Água/análise
, Extração em Fase Sólida/métodos
, Peixes
, Cátions/análise
RESUMO
Organophosphate triesters are compounds widely used in industries and are ubiquitous in the environment, where they can be transformed into organophosphate diesters. Some organophosphate diesters are also used by industry. Several studies suggest organophosphate diesters can have toxic effects for reproduction, and hazardous and mutagenic properties. Due to the impact these compounds can have on marine biota and human beings through the consumption of fish and shellfish, it is necessary to study their presence in widely consumed seafood species. We therefore developed an analytical method for determining six of the most common organophosphate diesters in seafood. The procedure is based on the Quick, Easy, Cheap, Effective, Rugged and Safe extraction method and a solid phase extraction clean-up, followed by liquid chromatography coupled to high-resolution mass spectrometry. The method was optimised and validated for seafood with different lipid content, providing satisfactory relative recoveries (from 89 to 138%) and limits of detection (1.0-50 ng g-1 dry weight), as well as repeatability values (RSD% (n = 5, 100 ng g-1 (dry weight)) lower than 15%. Eight seafood species were analysed using this method and two organophosphate diesters were detected and quantified in all the samples, demonstrating the suitability of the method.
Assuntos
Extração em Fase Sólida , Espectrometria de Massas em Tandem , Animais , Humanos , Espectrometria de Massas em Tandem/métodos , Extração em Fase Sólida/métodos , Cromatografia Líquida/métodos , Alimentos Marinhos/análise , Organofosfatos/análise , Ésteres/análise , Cromatografia Líquida de Alta Pressão/métodosRESUMO
In this paper, we provide a detailed description of the application of passive sampling with Carbopack X tubes followed by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) to determine the concentrations of volatile organic compounds (VOCs) in different school environments. The main objective of the study was to monitor VOCs in seven indoor and three outdoor environments at a school in Tarragona, Spain. However, in order to obtain more accurate information, it was necessary to determine the experimental diffusive uptake rates of the target VOCs in indoor settings through parallel passive and active sampling in one classroom. The results showed experimental diffusive uptake rates in the range of 0.38 mL min-1 and 0.95 mL min-1 with RSD % below 5% for up to 44 VOCs. The monitoring results showed that ethanol (23.84-83.16 µg m-3 ) and isopropyl alcohol (5.42-25.92 µg m-3 ) were the most common compounds found in indoor environments, with cleaning products as the main emission source. The VOCs i-pentane and n-pentane were found at the highest concentrations in the three sampling sites set in the school's playground, and their concentrations were strictly related to combustion processes from automobile traffic.
Assuntos
Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , Monitoramento Ambiental/métodos , Instituições Acadêmicas/estatística & dados numéricos , Adsorção , Poluição do Ar , Poluição do Ar em Ambientes Fechados/análise , Difusão , Cromatografia Gasosa-Espectrometria de Massas , Pentanos , Espanha , Compostos Orgânicos Voláteis/análiseRESUMO
Two different columns-Lux Cellulose-1 and Chiralpak CBH-were evaluated for their chiral recognition abilities for eight drugs comprising three ß-blockers, one antacid, and four cathinones in polar-organic elution mode and reversed-phase elution mode, respectively. The factors that affected the enantioseparation were tested and optimized to develop a suitable chiral separation method whose LC conditions are compatible with MS detection. In polar-organic elution mode with the Lux Cellulose-1 column, methanol and acetonitrile were tested as the main components of the mobile phase. In addition, the effects of adding isopropanol as organic modifier, acidic additives (formic acid), and basic additives (diethylamine) were evaluated. In reversed-phase elution mode with the Chiralpak CBH column, the effect of type and concentration of organic modifier (isopropanol, acetonitrile, and methanol), the mobile phase pH (6.4 and 5.0), and buffer concentration (1mM-20mM ammonium acetate) were evaluated. The best enantioseparation was achieved with the Chiralpak CBH column with a mobile phase composed of 5mM ammonium acetate aqueous (pH = 6.4)/methanol (95/5, v/v) at a flow rate of 0.1 mL/min and a temperature of 30°C. Under these conditions, six of eight chiral drugs were baseline separated.
Assuntos
2-Propanol/química , Antagonistas Adrenérgicos beta/química , Celulose/química , Fenilcarbamatos/química , Polissacarídeos/química , Acetonitrilas , Concentração de Íons de Hidrogênio , Preparações Farmacêuticas , Estereoisomerismo , TemperaturaRESUMO
The aim of the present study is to broaden the applications of mixed-mode ion-exchange solid-phase extraction sorbents to extract both basic and acidic compounds simultaneously by combining the sorbents in a single cartridge and developing a simplified extraction procedure. Four different cartridges containing negative and positive charges in the same configuration were evaluated and compared to extract a group of basic, neutral, and acidic pharmaceuticals selected as model compounds. After a thorough optimization of the extraction conditions, the four different cartridges showed to be capable of retaining basic and acidic pharmaceuticals simultaneously through ionic interactions, allowing the introduction of a washing step with 15 mL methanol to eliminate interferences retained by hydrophobic interactions. Using the best combined cartridge, a method was developed, validated, and further applied to environmental waters to demonstrate that the method is promising for the extraction of basic and acidic compounds from very complex samples.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Preparações Farmacêuticas/isolamento & purificação , Rios/química , Extração em Fase Sólida/métodos , Águas Residuárias/análise , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Ânions/química , Cátions/química , Limite de Detecção , Espectrometria de Massas/métodos , Preparações Farmacêuticas/análise , Poluentes Químicos da Água/análiseRESUMO
A novel sample preparation technique named capsule phase microextraction (CPME) is presented here. The technique utilizes a miniaturized microextraction capsule (MEC) as the extraction medium. The MEC consists of two conjoined porous tubular polypropylene membranes, one of which encapsulates the sorbent through sol-gel technology, while the other encapsulates a magnetic metal rod. As such, MEC integrates both the extraction and stirring mechanisms into a single device. The aim of this article is to demonstrate the application potential of CPME as sample preparation technique for the extraction of a group of personal care products (PCPs) from water matrices. Among the different sol-gel sorbent materials (UCON®, poly(caprolactone-dimethylsiloxane-caprolactone) (PCAP-DMS-CAP) and Carbowax 20M (CW-20M)) evaluated, CW-20M MEC demonstrated the best extraction performance for the selected PCPs. The extraction conditions for sol-gel CW-20M MEC were optimized, including sample pH, stirring speed, addition of salt, extraction time, sample volume, liquid desorption solvent, and time. Under the optimal conditions, sol-gel CW-20M MEC provided recoveries, ranging between 47 and 90% for all analytes, except for ethylparaben, which showed a recovery of 26%. The method based on CPME with sol-gel CW-20M followed by liquid chromatography-tandem mass spectrometry was developed and validated for the extraction of PCPs from river water and effluent wastewater samples. When analyzing different environmental samples, some analytes such as 2,4-dihydroxybenzophenone, 2,2-dihydroxy-4-4 methoxybenzophenone and 3-benzophenone were found at low ng L-1.
RESUMO
A method based on liquid chromatography with electrospray ionization high-resolution mass spectrometry (Exactive Orbitrap) combined with solid-phase extraction using a strong cationic exchange mixed-mode sorbent has been developed for the determination of seven drugs of abuse, including two synthetic cathinones, as well as some of their metabolites in environmental water samples. The method provides low detection limits and a high confirmation power thanks to the diagnostic and two fragment ions monitored for each compound in high-resolution mass spectrometry, providing six identification points for each analyte. The clean-up step based on methanol in the extraction step adequately decreased the matrix effect, mainly for river and effluent water, and provided suitable process efficiency. Method detection and quantitation limits for environmental waters were at low nanogram per liter. The method was applied to analyze the samples of influent and effluent wastewater, as well as surface water. Codeine, methadone, and its metabolite were determined in all samples of wastewater and the metabolite of cocaine, benzoylecgonine, was found at the highest concentration.
Assuntos
Drogas Ilícitas/análise , Águas Residuárias/análise , Poluentes Químicos da Água/análise , Cromatografia Líquida , Extração em Fase Sólida , Espectrometria de Massas em TandemRESUMO
Artificial sweeteners are food additives employed as sugar substitutes which are now considered to be emerging organic contaminants. In the present study, a method is developed for the determination of a group of artificial sweeteners in environmental waters. Considering the polar and hydrophilic character of these compounds, hydrophilic interaction liquid chromatography is proposed for their separation as an alternative to traditional reversed-phase liquid chromatography. Two stationary phases with different chemistry were compared for this purpose. For the detection of the analytes, high-resolution mass spectrometry (Orbitrap) was employed to take advantage of its benefits in terms of reliable quantification and confirmation for the measurement of accurate masses. Solid-phase extraction was chosen as the sample treatment, in which the extract in a mixture of NH4OH:MeOH:ACN (1:4:15) was directly injected into the chromatographic system, simplifying the analytical procedure. The optimized method was validated on river and waste water samples. For example, in the case of effluent water samples, limits of detection ranged from 0.002 to 0.7 µg/L and limits of quantification ranged from 0.004 to 1.5 µg/L. Apparent (whole method) recoveries ranged from 57 to 74% with intra-day precision (%RSD, n = 5) ranging from 6 to 25%. The method was successfully applied to water samples from different rivers in Catalonia and different waste water treatment plants in Tarragona. Acesulfame, cyclamate, saccharine and sucralose were found in several samples.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Rios/química , Edulcorantes/análise , Águas Residuárias/análise , Poluentes Químicos da Água/análise , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Extração em Fase Sólida/métodosRESUMO
This study investigates the occurrence of 37 organohalogen and organophosphate flame retardants (FRs) from Norwegian households (n = 48) and classrooms from two primary schools (n = 6). Around 80% of the targeted FRs were detected in air and dust from the sampling sites. The comparison of settled dust with floor dust revealed no statistical differences between median concentrations of the FRs (n = 12). Decabromodiphenyl ether and tris(2-butoxyethyl) phosphate showed the highest median floor dust concentrations in both environments. In the air samples, the highest concentrations were observed for 2,2',4,4'-tetrabromodiphenyl ether and tris(1-chloro-2-propyl) phosphate. Remarkably, the emerging FR, 4-(1,2-dibromoethyl)-1,2-dibromocyclohexane, abbreviated as TBECH or DBE-DBCH, showed the highest indoor air concentrations reported in the literature (households, 77.9 pg/m(3) and schools, 46.6 pg/m(3)). Good Spearman correlations between the FR concentrations in dust and air (0.36 < R < 0.76) showed that is possible to estimate the concentrations in air from analyzed dust, or vice versa. Sources and pathways of exposure to FRs were assessed for the households. The main findings were that frequent vacuum cleaning resulted in lower FR concentrations in dust and that dermal contact with dust, for both children and mothers, was as important for the intake of organophosphate FRs as dust ingestion.
Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental , Retardadores de Chama/análise , Adulto , Ar/análise , Poluentes Atmosféricos/química , Criança , Poeira/análise , Feminino , Pisos e Cobertura de Pisos , Humanos , Hidrocarbonetos Bromados/análise , Hidrocarbonetos Bromados/química , Masculino , Noruega , Organofosfatos/análise , Organofosfatos/químicaRESUMO
Iodinated X-ray contrast media are the most widely used pharmaceuticals for intravascular administration in X-ray diagnostic procedures. The increasing concern of the fate of these compounds into the environment has led to the development of analytical methods to determine them. However, these methods present problems due to the polar character of these analytes. In this paper, hydrophilic interaction LC is presented as an alternative technique. The retention of iodinated X-ray contrast media was studied in two bare silica phases with different particle designs (i.e. porous and Fused Core™) and a zwitterionic sulfoalkylbetaine phase. The effect of the most important parameters of the mobile phase was studied for each stationary phase. It was observed that optimal mobile phase conditions included buffers with a high buffering capacity. Additionally, the retention mechanisms involved were studied in order to provide some insight into the possible occurring interactions. The contributions of partition and adsorption and the effect of the temperature on the retention of analytes were evaluated on all of the stationary phases.
Assuntos
Betaína/química , Meios de Contraste/química , Dióxido de Silício/química , Betaína/análogos & derivados , Cromatografia Líquida , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Porosidade , Propriedades de Superfície , Raios XRESUMO
This paper describes a method for the determination of eight sedative hypnotics (benzodiazepines and barbiturates) in sewage sludge using pressurized liquid extraction and liquid chromatography with tandem mass spectrometry. Pressurized liquid extraction operating conditions were optimized and maximum recoveries were reached using methanol under the following operational conditions: 100ºC, 1500 psi, extraction time of 5 min, one extraction cycle, flush volume of 60% and purge time of 120 s. Pressurized liquid extraction recoveries were higher than 88% for all the compounds except for carbamazepine (55%). The repeatability and reproducibility between days, expressed as relative standard deviation (n = 5), were lower than 6 and 10%, respectively. The detection limits for all compounds were lower than 12.5 µg/kg of dry weight. The method was applied to determine benzodiazepines and barbiturates in sewage sludge from urban sewage treatment plants, and carbamazepine showed the highest concentration (7.9-18.9 µg/kg dry weight).
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Hipnóticos e Sedativos/química , Hipnóticos e Sedativos/isolamento & purificação , Extração Líquido-Líquido/métodos , Esgotos/química , Espectrometria de Massas em Tandem/métodosRESUMO
Polar vinyl monomers have been used for the synthesis of several polymer monoliths, to serve as novel coatings for stir bar sorptive extraction; the monovinyl monomers 2-hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol) monomethacrylate) (PEGMA) were copolymerized with (apolar) divinylbenzene (DVB) and/or pentaerythritol triacrylate (PETRA), both of which are cross-linking agents. After the optimization of the most important synthesis parameters, which included the ratio between total monomers and porogen, the nature of the porogen, and the monomer ratios, inter alia, three mechanically stable, polar monolithic coatings for stir bar sorptive extraction were obtained that were based on poly(HEMA-co-DVB), poly(HEMA-co-PETRA), and poly(PEGMA-co-PETRA). Thereafter, and in order to evaluate the hydrophilicity of the resulting monoliths, they were applied as materials in the stir bar sorptive extraction of a group of emerging pollutants with a wide range of polarities. The results showed that both the poly(HEMA-co-DVB) and poly(PEGMA-co-PETRA) materials could be used to extract both polar and nonpolar compounds by stir bar sorptive extraction, in an effective manner. Taking into account the desired chemical and morphological properties, as well as the extraction efficiencies, the poly(PEGMA-co-PETRA) material seemed to be a particularly promising monolith for application as a novel coating in stir bar sorptive extraction.
RESUMO
The aquatic ecosystem is one of the most delicate environments, housing a diverse range of organisms, including fish, all of which are exposed to a wide variety of pollutants. The accumulation of these harmful substances in fish, which are part of the human diet, presents a significant health risk to humans. In our study, we have optimized an extraction technique to determine the presence of 25 high production volume chemicals in liver and skin samples taken from commonly consumed fish species. We have employed ultrasound-assisted extraction in conjunction with gas chromatography tandem mass spectrometry to achieve this goal. Apparent recoveries of the method ranged from 50% to 111% for both sample types with some exceptions such as most of the benzosulfonamides and benzothiazole. Additionally, the method's detection and quantification limits varied from 0.1 to 1.7 ng g-1 (dry weight, d.w) and 0.2-4.5 ng g-1 (d.w), respectively. Our investigation focused on three frequently consumed fish species in Tarragona: sea bass, sea bream, and turbot. Almost all of the samples we analysed contained traces of contaminants, with phthalates being the most commonly detected. The highest concentrations were observed for diethyl phthalate, with levels peaking at 8350 ng g-1 (d.w.). Organophosphate esters, such as triethyl phosphate and tributyl phosphate, also showed notable presence, with peak concentrations of 93.6 and 34.0 ng g-1 (d.w.), respectively.
Assuntos
Dourada , Espectrometria de Massas em Tandem , Animais , Humanos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Massas em Tandem/métodos , Ecossistema , FígadoRESUMO
This study describes the use of passive sampling followed by pressurised liquid extraction and gas chromatography-mass spectrometry for monitoring high production volume chemicals (HPVCs), such as benzothiazoles, benzesulfonamides, phthalate esters (PAEs), organophosphate esters, ultraviolet stabilizers, and phenolic antioxidants and polycyclic aromatic hydrocarbons (PAHs) in urban atmospheres close to a petrochemical area. To obtain accurate results when applying passive sampling, the uptake rates of each target compound for the sampling time applied must be known. Firstly, passive sampling was calibrated for two months and uptake rates of HPVCs and PAHs in an urban atmosphere determined using active sampling as the reference method. The obtained results showed experimental diffusive uptake rates between 1.6 m3 day-1 and 27 m3 day-1 for 32 of the target compounds that will allow enable cost-effective long-term monitoring campaigns of HPVCs to be performed. Secondly, the experimentally obtained uptake rates were used to monitor the concentrations of HPVCs and PAHs at six urban sampling sites close to the two petrochemicals parks in Tarragona (Spain) during a period the two months. Regardless of the sampling campaign, PAEs and PAHs were the families of compounds found at the highest concentration levels, with a sum of their mean values of 23 ng m-3 and 20 ng m-3, respectively.
RESUMO
Evaluating the occurrence of high production volume chemicals (HPVCs) and polycyclic aromatic hydrocarbons (PAHs) in the air is important because they carry a carcinogenic risk and can lead to respiratory or endocrine problems. Examples of HPVCs are organophosphate esters, benzosulfonamides, benzothiazoles, phthalate esters (PAEs), phenolic antioxidants and ultraviolet stabilizers. In this paper we develop a multi-residue method for determining HPVCs and PAHs in air samples via pressurized liquid extraction followed by gas chromatography-mass spectrometry. Air samples were collected by active sampling with high volume samplers using quartz fiber filter for the particulate matter (PM10) and polyurethane foams for gas phase. The compounds found at the highest concentrations were PAEs, with a concentration of up to 24 ng m-3 of DEHP in gas phase and up to 109 ng m-3 of DEHA in PM10. Non-carcinogenic risk assessment results ranged from 9.7E-05 to 9.5E-03 for most of the compounds studied. On the other hand, the results for carcinogenic risk showed that PAHs made the highest contribution.
Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Humanos , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , Carcinógenos/análise , Medição de RiscoRESUMO
Although most of the analytical methods developed for the monitoring of contaminants in environmental waters are based on discrete grab sampling, an alternative of increasing interest is the use of passive sampling. Methods based on passive sampling provide the sampling and pre-concentration of the analytes in-situ, which makes the sample treatment less time consuming and costly than using discrete grab sampling. In this study, ceramic passive samplers (CPSs) using mixed-mode strong cation-exchange sorbent (Oasis MCX) as retention phase were evaluated for the determination of a group of 21 therapeutic and illicit drugs and some of their metabolites in river water samples that were determined by liquid chromatography-tandem mass spectrometry. After assessing the stability of the analytes, the CPSs were calibrated for 9 days with bottled water and river water, obtaining, for the 19 stable compounds, sample rates (Rs) ranging between 0.180 and 1.767 mL/day and diffusion coefficients (De) between 2.02E-8 and 2.81E-7 cm2/s. Once calibrated, CPSs were deployed for the determination of contaminants in the Ebre River, with good reproducibility, and some of the analytes were determined, including amongst others, gabapentin at 76 ng/L, caffeine at 203 ng/L or diclofenac amine at 57 ng/L. The passive sampling method herein presented is simple and feasible and allows the time-integrated analysis of pharmaceuticals and drugs at trace levels in river water. This study opens the possibility of using other mixed-mode sorbents or other types of sorbents as retaining phase on CPSs for the determination of very polar contaminants in water.
Assuntos
Rios , Água , Reprodutibilidade dos Testes , Cátions , CerâmicaRESUMO
An important challenge today is to efficiently monitor the presence of polar pharmaceuticals and drugs in surface and drinking waters to ensure its safeness. Most studies rely on grab sampling techniques, which enable the determination of contaminants at a given point and given time. In this study, we propose the use of ceramic passive samplers (CPSs) to increase the representativeness and efficiency of organic contaminant monitoring in waters. Firstly, we have assayed the stability of 32 pharmaceuticals and drugs and found that five of those compounds were unstable. Moreover, we evaluated the retention capabilities of three sorbents (Sepra ZT, Sepra SBD-L, and PoraPak Rxn RP) in solid-phase extraction (SPE) mode and found no differences in terms of recoveries for all three sorbents. We then calibrated CPSs using the three sorbents for the 27 stable compounds over 13 days, with a suitable uptake for 22 compounds with sampling rates between 0.4 and 17.6 mL/day, which indicates high uptake efficiency. CPSs with the Sepra ZT sorbent were deployed in river water (n = 5) and drinking water (n = 5) for 13 days. Some of the studied compounds occurred with a time-weighted concentration, for instance, of 43 ng/L for caffeine, 223 ng/L for tramadol or 175 ng/L for cotinine in river water.
Assuntos
Água Potável , Poluentes Químicos da Água , Rios , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Cerâmica , Preparações FarmacêuticasRESUMO
A novel sol-gel silica-based mixed-mode zwitterionic sorbent modified with graphene microparticles was synthesized. Thanks to the inclusion of multiple functional groups and graphene microparticles to exert a wide range of intermolecular/interionic interactions including dipole-dipole interactions, ion-exchange interactions and π-π interactions, the sorbent showed high retention in the solid-phase extraction (SPE) of benzothiazoles, benzotriazoles and benzenesulfonamides. The SPE protocol was optimized in terms of pH, sample loading volume and elution conditions using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). The method based on SPE followed by LC-HRMS was validated. Apparent recoveries at two levels of concentration were in the range from 48 to 85% (in most cases) in matrices such as influent wastewater, matrix effect was lower than ±30% in most cases, method detection and quantification limits being lower than 20 ng/L and repeatability and reproducibility between days were lower than 18% (n = 4). River, effluent and influent wastewaters samples were analyzed, obtaining concentrations ranging from 3 to 175 ng/L in river samples, from 12 to 499 ng/L in effluent samples and from 15 to 632 ng/L in influent samples, when the compounds were above the method quantification limits.
RESUMO
Four different commercial sorbents for solid-phase extraction have been evaluated for the extraction of a group of acidic pharmaceuticals in terms of selectivity and capacity: Oasis hydrophilic-lipophilic balance (HLB), Oasis MAX (strong anion exchange), Oasis WAX (weak anion exchange) and a commercial available molecularly imprinted polymer specific for non-steroidal anti-inflammatory drugs. Among the sorbents studied, molecularly imprinted polymer proved to be very effective in the reduction of matrix interferences and the selective extraction of acidic pharmaceuticals, such as salicylic acid, ibuprofen, fenoprofen, diclofenac and naproxen, among others, from effluent wastewater samples. Moreover, molecularly imprinted solid-phase extraction protocol was applied to liquid chromatography coupled to tandem mass spectrometry (MS/MS) with the purpose of evaluating the clean-up effect on ion suppression/enhancement when the complexity of the samples increases and a reduction of this effect was observed. Molecularly imprinted solid-phase extraction followed by liquid chromatography coupled to ultraviolet detection and liquid chromatography coupled to tandem mass spectrometry validation methodologies with effluent wastewaters were developed, obtaining recoveries between 70 and 85% and limits of detection at low levels of µg/L (0.15-1 µg/L) and ng/L (0.5-2 ng/L), respectively. The final application of molecularly imprinted solid-phase extraction and liquid chromatography coupled to MS/MS detection showed the presence of acidic pharmaceuticals studied in this work in effluent wastewaters (Assuntos
Cromatografia Líquida/métodos
, Preparações Farmacêuticas/análise
, Esgotos/química
, Extração em Fase Sólida/métodos
, Espectrometria de Massas em Tandem/métodos
, Poluentes Químicos da Água/análise
, Preparações Farmacêuticas/isolamento & purificação
, Poluentes Químicos da Água/isolamento & purificação
RESUMO
This study focuses on a method for simultaneously determining personal care products in a wide range of polarities in different water matrices. The method is based on stir-bar sorptive extraction followed by thermal desorption-gas chromatography-mass spectrometry. Prior to extraction, the parabens were acetylated to improve their affinity for the polydimethylsiloxane phase of the stir bar. The method showed good linearity, repeatability and reproducibility between days for all compounds and limits of detection at low ng/L levels (between 0.02 and 0.3 ng/L). The proposed method is also environmentally friendly, because it does not use organic solvents, and reduces the risk of external pollution, due to the minimal manipulation of the sample required. The method developed was successfully applied for the analysis of personal care products in different kinds of water matrices: influents and effluents of urban and industrial wastewater treatment plants, effluents of a reverse osmosis treatment plant and river waters. The influents of urban treatment plants generally showed the highest values for synthetic musks, with concentrations of up to 2219 ng/L of galaxolide, whereas the highest concentrations of parabens were detected in the industrial treatment plants influents.