Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Aquat Toxicol ; 244: 106095, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35121565

RESUMO

The primary focus of environmental toxicological studies is to address the direct effects of chemicals on exposed organisms (parental generation - F0), mostly overlooking effects on subsequent non-exposed generations (F1 and F2 - intergenerational and F3 transgenerational, respectively). Here, we addressed the effects of simvastatin (SIM), one of the most widely prescribed human pharmaceuticals for the primary treatment of hypercholesterolemia, using the keystone crustacean Gammarus locusta. We demonstrate that SIM, at environmentally relevant concentrations, has significant inter and transgenerational (F1 and F3) effects in key signaling pathways involved in crustaceans' neuroendocrine regulation (Ecdysteroids, Catecholamines, NO/cGMP/PKG, GABAergic and Cholinergic signaling pathways), concomitantly with changes in apical endpoints, such as depressed reproduction and growth. These findings are an essential step to improve hazard and risk assessment of biological active compounds, such as SIM, and highlight the importance of studying the transgenerational effects of environmental chemicals in animals' neuroendocrine regulation.


Assuntos
Anfípodes , Poluentes Químicos da Água , Animais , Reprodução , Sinvastatina/toxicidade , Poluentes Químicos da Água/toxicidade
2.
Sci Total Environ ; 805: 150384, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34818755

RESUMO

The bioaccumulation and depuration of seven organophosphorus flame retardants (OPFRs) in marine mussel Mytilus galloprovincialis were studied. OPFRs showed to be bioavailable in aquatic environments. When mussels are exposed to environmentally relevant concentrations of OPFRs, uptake kinetics fit well to a first-order model with a single compartment; in contrast depuration rates were generally underestimated by that model, most likely because it does not take into account the biotransformation of OPFRs by the organisms. The highest bioaccumulation rates were observed for tricresyl phosphate (TCrP), triphenyl phosphate (TPhP) and 2-ethylhexyldiphenylphosphate (EHDPP). This could be due to the presence of aryl groups in these compounds, their low solubility in water, and their affinity for fat tissues. According to these findings TCrP, with a BCF value of 4042 L kg-1 wet weight, should be classified in environmental regulations as an accumulative chemical.


Assuntos
Retardadores de Chama , Mytilus , Animais , Bioacumulação , Cinética , Organofosfatos , Compostos Organofosforados
3.
Sci Total Environ ; 767: 144976, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33636779

RESUMO

Plastics accumulation in marine ecosystems has notable ecological implications due to their long persistence, potential ecotoxicity, and ability to adsorb other pollutants or act as vectors of pathogens. The present work aimed to evaluate the physiological response of the gilthead seabream (Sparus aurata) fed for 90 days with a diet enriched with virgin and seawater exposed low-density polyethylene microplastics (LDPE-MPs) (size between 100 and 500 µM), followed by 30 days of depuration, applying oxidative stress and inflammatory markers in liver homogenates. No effects of LDPE-MPs treatments on fish growth were observed throughout this study. A progressive increase in antioxidant enzyme activities was observed throughout the study in both treatments, although this increase was higher in the group treated with seawater exposed MPs. This increase was significantly higher in catalase (CAT), glutathione reductase (GRd), and glutathione-s-transferase (GST) in the seawater exposed MPs group, with respect to the virgin group. In contrast, no significant differences were recorded in superoxide dismutase (SOD) and glutathione peroxidase (GPx) between both groups. Exposure to MPs also caused an increase in the oxidative damage markers (malondialdehyde and carbonyls groups). Myeloperoxidase activity significantly increased because of MPs treatments. After 30 days of depuration, antioxidant, inflammatory enzyme activities and oxidative damage markers returned to values similar to those observed in the control group. In conclusion, MPs exposure induced an increase of antioxidant defences in the liver of S. aurata. However, these elevated antioxidant capabilities were not enough to prevent oxidative damage in the liver since, an increased oxidative damage marker was associated with MPs ingestion. The treatment with seawater exposed MPs caused a more significant antioxidant response (CAT, GRs, and GST). Although after a depuration period of 30 days a tendency to recover the initial values of the biomarkers was observed this does not seem to be time enough for a complete normalization.


Assuntos
Dourada , Poluentes Químicos da Água , Animais , Catalase/metabolismo , Dieta , Ecossistema , Inflamação , Fígado/química , Microplásticos , Estresse Oxidativo , Plásticos/metabolismo , Plásticos/toxicidade , Dourada/metabolismo , Água do Mar , Poluentes Químicos da Água/análise
4.
Environ Int ; 144: 106020, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32861161

RESUMO

The hypothesis that exposure to certain environmental chemicals during early life stages may disrupt reproduction across multiple non-exposed generations has significant implications for understanding disease etiology and adverse outcomes. We demonstrate here reproductive multi and transgenerational effects, at environmentally relevant levels, of one of the most prescribed human pharmaceuticals, simvastatin, in a keystone species, the amphipod Gammarus locusta. The transgenerational findings has major implications for hazard and risk assessment of pharmaceuticals and other contaminants of emerging concern given that transgenerational effects of environmental chemicals are not addressed in current hazard and risk assessment schemes. Considering that the mevalonate synthesis, one of the key metabolic pathways targeted by simvastatin, is highly conserved among metazoans, these results may also shed light on the potential transgenerational effects of simvastatin on other animals, including humans.


Assuntos
Anfípodes , Sinvastatina , Animais , Epigênese Genética , Humanos , Reprodução , Sinvastatina/toxicidade
5.
Arch Environ Contam Toxicol ; 72(4): 606-611, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28391487

RESUMO

The growing concern regarding the negative effects of solar radiation on the skin has led to a drastic increase in the use of sunscreens containing in its composition up to 10% of aromatic chemicals, such as ethylhexyl dimethyl p-aminobenzoic acid (OD-PABA) and octocrylene (OC). The objective of this study was to evaluate the toxicity and to assess the environmental risk posed by these two ultraviolet filters, widely used in cosmetics and as plastic additives, in the marine environment. Several ecotoxicological bioassays were performed with three model organisms belonging to different trophic levels: the microalgae Isochrysis galbana, the mussel Mytilus galloprovincialis, and the sea urchin Paracentrotus lividus. The results show remarkable toxicity to marine species for both OD-PABA (EC10 values range 26,5-127 µg L-1) and OC (EC10 range 103-511 µg L-1). The cell division in the microalgae I. galbana was the most sensitive endpoint tested. To determine the environmental risk of these substances, the risk coefficient (RQ) was calculated. Due to the higher concentrations reported, OC showed remarkable risk (RQ = 0.27), whereas for OD-PABA the risk was low (RQ = 0.007).


Assuntos
Acrilatos/toxicidade , Organismos Aquáticos/fisiologia , Protetores Solares/toxicidade , Testes de Toxicidade/métodos , Poluentes Químicos da Água/toxicidade , para-Aminobenzoatos/toxicidade , Animais , Monitoramento Ambiental , Haptófitas , Mytilus , Paracentrotus , Medição de Risco
6.
Environ Sci Pollut Res Int ; 23(4): 3847-59, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26498966

RESUMO

The uptake of polybrominated diphenyl ethers (PBDEs) by carrot and lettuce was investigated. Degradation of PBDEs in soil in the absence of the plants was discarded. Different carrot (Nantesa and Chantenay) and lettuce (Batavia Golden Spring and Summer Queen) varieties were grown in fortified or contaminated compost-amended soil mixtures under greenhouse conditions. After plant harvesting, roots (core and peel) and leaves were analyzed separately for carrot, while for lettuce, leaves and hearts were analyzed together. The corresponding bioconcentration factors (BCFs) were calculated. In carrots, a concentration gradient of 2,2',3,4,4',5'-hexabromodiphenyl ether (BDE-138) became evident that decreased from the root peel via root core to the leaves. For decabromodiphenyl ether (BDE-209) at the low concentration level (7 and 20 ng g(-1)), the leaves incorporated the highest concentration of the target substance. For lettuce, a decrease in the BCF value (from 0.24 to 0.02) was observed the higher the octanol-water partition coefficient, except in the case of BDE-183 (BCF = 0.51) and BDE-209 (BCF values from 0.41 to 0.74). Significant influence of the soils and crop varieties on the uptake could not be supported. Metabolic debromination, hydroxylation or methylation of the target PBDEs in the soil-plant system was not observed.


Assuntos
Daucus carota/metabolismo , Éteres Difenil Halogenados/metabolismo , Lactuca/metabolismo , Poluentes do Solo/metabolismo , Solo , Produtos Agrícolas/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo
7.
J Chromatogr A ; 1360: 57-65, 2014 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-25130091

RESUMO

In the present work, a novel analytical method for the simultaneous determination of ten polybrominated diphenyl ethers (PBDEs), eight methoxylated PBDEs (MeO-PBDEs) and seven hydroxylated PBDEs (OH-PBDEs) in soil, lettuce and carrot samples was developed. The procedure was based on matrix solid-phase dispersion (MSPD) followed by gas chromatography coupled to negative chemical ionization-mass spectrometry (GC-NCI-MS). Under optimum conditions, 0.5g of sample (freeze-dried in the case of lettuce and carrot samples) was dispersed with 0.5g of octadecyl-functionalized silica (C18) and 1.75g of acidified silica (10% H2SO4, w/w) was used as clean-up sorbent. A two-step fractionated elution was carried out. First, PBDEs and MeO-PBDEs were eluted in 75:25% (v/v) n-hexane/dichloromethane mixture and, then, the retained OH-PBDEs were eluted in pure dichloromethane. Both extracts were analyzed by GC-NCI-MS separately, in the case of OH-PBDEs after derivatization with N-methyl-N-(trimethylsilyl) trifluoroacetamide. The developed method was validated in terms of accuracy for soil, lettuce and carrot matrices, spiked at two fortification levels (5 and 25ngg(-1)). After correction with the corresponding surrogate, apparent recovery values (defined as the recovery obtained after correction with the corresponding surrogate) were in the 80-129% range. Precision (as relative standard deviation) in the 1-21% range and method detection limits (MDLs) in the 0.003 and 0.3ngg(-1) range for soil and in the 0.003-0.4ngg(-1) range (dry weight) for lettuce and carrot samples were obtained. For PBDEs the method was also validated with a standard reference material (SRM-2585) of house dust. Finally, the method was applied for the determination of target analytes in soil, lettuce and carrot.


Assuntos
Daucus carota/química , Éteres Difenil Halogenados/análise , Lactuca/química , Solo/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Éteres Difenil Halogenados/química , Hidroxilação , Limite de Detecção
8.
Chemosphere ; 104: 44-50, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24359924

RESUMO

Due to the concern about the negative effects of exposure to sunlight, combinations of UV filters like 4-Methylbenzylidene-camphor (4-MBC), Benzophenone-3 (BP-3), Benzophenone-4 (BP-4) and 2-Ethylhexyl-4-methoxycinnamate (EHMC) are being introduced in all kind of cosmetic formulas. These chemicals are acquiring a concerning status due to their increasingly common use and the potential risk for the environment. The aim of this study is to assess the behaviour of these compounds in seawater, the toxicity to marine organisms from three trophic levels including autotrophs (Isochrysis galbana), herbivores (Mytilus galloprovincialis and Paracentrotus lividus) and carnivores (Siriella armata), and set a preliminary assessment of potential ecological risk of UV filters in coastal ecosystems. In general, EC50 results show that both EHMC and 4-MBC are the most toxic for our test species, followed by BP-3 and finally BP-4. The most affected species by the presence of these UV filters are the microalgae I. galbana, which showed toxicity thresholds in the range of µg L(-1) units, followed by S. armata>P. Lividus>M. galloprovincialis. The UV filter concentrations measured in the sampled beach water were in the range of tens or even hundreds of ng L(-1). The resulting risk quotients showed appreciable environmental risk in coastal environments for BP-3 and 4-MBC.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Protetores Solares/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Benzofenonas/toxicidade , Cânfora/análogos & derivados , Cânfora/toxicidade , Cinamatos/toxicidade , Crustáceos/efeitos dos fármacos , Ecotoxicologia , Haptófitas/efeitos dos fármacos , Mytilus/efeitos dos fármacos , Paracentrotus/efeitos dos fármacos , Água do Mar/análise
9.
J Chromatogr A ; 1287: 2-22, 2013 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-22901328

RESUMO

The computer-assisted development of separation procedures in liquid chromatography (LC), which has involved the adaptation of diverse chemometric techniques and the incorporation of successive advances in informatics and computing over a period of more than four decades, has provided chromatographers with commercial and academic tools of great utility. These tools enable the development, optimization (including robustness studies) and transfer of procedures that constitute one of the analytical activities most commonly used at present in laboratories and industries worldwide. Departing from a typical operational scheme of manually developed chromatographic procedures, this review describes some of the different tools and options that chemometrics provides to the chromatographer for the computer-assisted approach, and outlines the present status of this approach and possible reasons why it is still not considered fully satisfactory.


Assuntos
Cromatografia de Fase Reversa/métodos , Redes Neurais de Computação , Processamento de Sinais Assistido por Computador
10.
Anal Bioanal Chem ; 398(5): 2289-97, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20809191

RESUMO

An expeditious method for the determination of triclosan (TCS) and methyl triclosan (MTCS) in sludge and sediment samples is presented. Extraction and cleanup steps were integrated in the same process using matrix solid-phase dispersion as sample preparation technique. Effects of different variables on the efficiency and the selectivity of the sample preparation process are discussed. Under final working conditions, samples (0.5 g) were dispersed with diatomaceous earth (1 g) and transferred to a polypropylene syringe containing 2 g of silica impregnated with sulphuric acid (15%, w:w). Analytes were recovered with 10 mL of dichloromethane. After solvent exchange to ethyl acetate, TCS was converted into the tert-butyldimethylsilyl derivative, and the extract was analysed by gas chromatography-mass spectrometry, without any additional cleanup. Obtained recoveries, for sludge and sediment samples spiked at different concentration levels, ranged from 86% to 113%, with associated standard deviations between 2 and 13%. Limits of quantification of the global method were 6 and 7 ng g(-1) for MTCS and TCS, respectively. Both compounds were detected in all the processed sludge samples with maximum concentrations of 191 ng g(-1) (MTCS) and 2,640 ng g(-1) (TCS). The parent bactericide was also found in some sediment samples at concentrations up to 200 ng g(-1).


Assuntos
Monitoramento Ambiental/métodos , Cromatografia Gasosa-Espectrometria de Massas , Esgotos/química , Triclosan/análogos & derivados , Triclosan/análise
11.
Talanta ; 81(4-5): 1189-96, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20441883

RESUMO

Several interlaboratory exercises were organised within the framework of European FP6 project NORMAN. Among others, non-steroidal anti-inflammatory drugs were investigated in different aqueous samples in two sequential ring studies. The aim of both studies was to evaluate the state-of-art in Europe and to determine possible sources of variation, while also attempting to diminish them. In the present paper we discuss the results of the 2nd Interlaboratory study, while the results of 1st round were presented before. The main scope of the 1st exercise organised within NORMAN project was to assess the laboratory proficiency regardless of the analytical method applied, to evaluate the stability of the target compounds during sample storage, and to define possible sources of variation during sample shipment, storage and analysis. In the 2nd round we primarily aimed to diminish these sources of variation by applying two predetermined analytical protocols based on liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry. The two analytical protocols were compared in terms of their ability to determine individual analytes in matrices of different complexity, i.e. tap water, river water and wastewater. Furthermore, the 2nd exercise addressed also the filtration and compared the influence of different filter material categories on the analysis of non-steroidal anti-inflammatory drugs. Results presented herein evaluate laboratory performance using z-score, bias, proximity and Youden plots. Overall, the laboratory performances were found to be satisfactory for determining NSAIDs in aqueous samples. The two analytical protocols, LC-MS and GC-MS, are assessed according to their sensitivity and measurement uncertainty, where the GC-MS proved superior for the analysis of Ibuprofen, Ketoprofen and Naproxen in matrices with higher complexity. Finally, neither the filtration itself, nor the filter materials were shown to significantly affect the determination of NSAIDs.


Assuntos
Anti-Inflamatórios não Esteroides/análise , Técnicas de Química Analítica , Monitoramento Ambiental/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Anti-Inflamatórios não Esteroides/química , Diclofenaco/análise , Filtração , Ibuprofeno/análise , Cetoprofeno/análise , Naproxeno/análise , Reprodutibilidade dos Testes
12.
Talanta ; 76(3): 580-90, 2008 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-18585324

RESUMO

Comparability of monitoring data are essential for any meaningful assessment and for the management of environmental risks of emerging pollutants. The reliability and comparability of data at European level is often limited, because analytical methods for emerging pollutants are often not fully validated, not harmonized or not suitable for all relevant matrices. This paper describes a collaborative interlaboratory exercise for the analysis of non-steroidal anti-inflammatory drugs (NSAIDs) residues in freshwater and wastewater, held in the framework of the EU project "Network of reference laboratories for monitoring of emerging environmental pollutants" (NORMAN). The NSAID compounds selected in this study were ketoprofen, naproxen, ibuprofen and diclofenac. Thirteen laboratories distributed along nine European Countries (Austria, France, Germany, Greece, Italy, Slovak Republic, Slovenia, Spain, and Switzerland) took part in this exercise, 126 samples were analyzed and a total number of 473 values in duplicate were collected. Samples selected in this study include environmental water (river water and waste water) and artificial water (fortified environmental and distilled water) with different ranges of complexity. Two analytical methods were proposed by the organiser; one is based on the use of solid phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the second one is based on SPE followed by gas-chromatography-mass spectrometry (GC-MS), however, in the first round some different approaches were also admitted. The main goals of this interlaboratory comparison were to evaluate the available analytical schemes for NSAID analysis in natural waters, to evaluate the repeatability (r) and reproducibility (R) between participating laboratories, and to evaluate the influence of the analytical method and sample matrices on the results.


Assuntos
Anti-Inflamatórios não Esteroides/análise , Cromatografia Gasosa-Espectrometria de Massas/normas , Espectrometria de Massas em Tandem/normas , Poluentes Químicos da Água/análise , Cromatografia Líquida , Europa (Continente) , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Extração em Fase Sólida
13.
J Chromatogr A ; 1108(2): 158-65, 2006 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-16442119

RESUMO

The feasibility of solid-phase microextraction (SPME) for the determination of several organophosphorus flame retardants and plastizicers in water samples by gas chromatography-nitrogen phosphorous detection (GC-NPD) is evaluated. These compounds have a wide range of polarities and volatilities and require a thorough optimisation of the different SPME parameters. Considering also possible contamination and carryover sources, the best compromise microextraction conditions were found to be direct extraction of 22 ml samples, containing 300 mg/ml of NaCl, with a PDMS-DVB coated fibre at room temperature. Although equilibrium was not achieved, an extraction time of 40 min allowed obtaining a good sensitivity (quantification limits between 0.010 and 0.025 ng/ml), comparable to that achieved by solid-phase extraction (SPE) of 1l samples, producing both similar values of precision and accuracy. Furthermore, the SPME method has shown to be free of matrix effects, avoiding the need of employing the standard addition procedure for quantification, and was suitable for the determination of eight of the nine considered compounds. Only tris-(2-ethylhexyl)-phosphate was neither determinable by SPME nor by SPE. Finally, the application of the developed methodology to the analysis of wastewater samples, showed that important concentrations of these compounds (up to 10 ng/ml) have been detected in treated sewage water, being discharged into the aquatic environment.


Assuntos
Retardadores de Chama/análise , Compostos Organofosforados/análise , Plastificantes/análise , Cromatografia Gasosa
14.
J Chromatogr A ; 1056(1-2): 179-85, 2004 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-15595548

RESUMO

A solvent-free method for the determination of five estrogens in water samples at the low ng/l was optimized. Compounds were first concentrated on a polyacrylate (PA) solid-phase microextraction (SPME) fiber, directly exposed to the water sample, and then on-fiber silylated on the headspace of a vial containing 50 microl of N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA). Derivatized analytes were determined using GC with MS/MS detection. Influence of several factors on the efficiency of the microextraction step (e.g. time, sample volume, pH, ionic strength and fiber coating) is systematically described. Derivatization conditions were optimized in order to achieve the complete silylation of all hydroxyl groups contained in the structure of the compounds. Detection limits (from 0.2 to 3 ng/l) are compared with those obtained using the same detection technique and different sample preparation strategies, such as solid-phase extraction followed by silylation of the analytes in the organic extract and SPME without derivatization. The method was applied to the analysis of sewage water samples. Two of the investigated species were detected above the quantification limits of the procedure.


Assuntos
Estrogênios/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Ácido N-Acetilneuramínico/análise , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Sensibilidade e Especificidade , Cloreto de Sódio/química
15.
Anal Chem ; 76(4): 1054-62, 2004 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-14961738

RESUMO

Solid-phase microextraction has been applied for the first time to the determination of trace concentrations of some brominated flame-retardant compounds (BFRs) in water samples. For the development of the method, six polybrominated diphenyl ethers and two polybrominated biphenyls were considered as target analytes. The factors expected to influence the extraction process are fully discussed. Quantification has been performed by gas chromatography/tandem mass spectrometry using an ion trap mass analyzer. This is also the first time that tandem mass spectrometry is applied with these analytes. Unlike conventional methods for BFR analysis, which involve solvent extraction and several cleanup steps before gas chromatography, the proposed method uses headspace extraction and hard contamination of the chromatographic system is prevented. In addition, tandem mass spectrometry provides selectivity and sensitivity in the detection process. The method performs well achieving good linearity (R(2) > 0.997), precision, and detection limits (S/N = 3) ranging from 7.5 to 190 pg/L. The method has been applied to a variety of water samples.

16.
J Chromatogr A ; 1024(1-2): 1-8, 2004 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-14753700

RESUMO

A sensitive and solvent-free procedure for the determination of non-steroidal acidic anti-inflammatory drugs in water samples was optimized using solid-phase microextraction (SPME) followed by on-fiber silylation of the acidic compounds and gas chromatography-mass spectrometry (GC-MS) determination. Microextraction was carried out directly over the filtered water samples using a polyacrylate fiber. Derivatization was performed placing the SPME fiber, loaded with the extracted analytes, in the headspace of a vial containing 50 microl of N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA). Derivatives were desorbed for 3 min in the GC injector. Influence of several parameters in the efficiency of microextraction (volume of sample, time, pH, type of fiber coating, etc.) and derivatization steps (time, temperature and volume of MTBSTFA) was systematically investigated. In the optimal conditions an excellent linearity over three orders of magnitude and quantification limits at the ng/l level (from 12 to 40 ng/l) were achieved. The proposed method was applied to the determination of acidic compounds in sewage water and results compared to those obtained using solid-phase extraction (SPE) followed by the derivatization of the compounds in the organic extract of the solid-phase extraction cartridge.


Assuntos
Anti-Inflamatórios não Esteroides/análise , Cromatografia Líquida/métodos , Poluentes Químicos da Água/análise , Cromatografia Gasosa-Espectrometria de Massas , Concentração de Íons de Hidrogênio , Cloreto de Sódio/química
17.
J Chromatogr A ; 1024(1-2): 177-85, 2004 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-14753720

RESUMO

A procedure for the determination of six natural and synthetic estrogens (diethylstilbestrol, estrone, 17beta-estradiol, mestranol, 17alpha-ethinylestradiol and estriol) in water samples is described. Samples, up to 2000 ml, were concentrated using Oasis HLB solid-phase extraction cartridges. Analytes were derivatized with N-methyl-N-(trimethylsilyl)trifluoroacetamide and determined by GC-MS or GC-MS-MS. The reactivity of several silylation reagents versus aliphatic and aromatic hydroxyl groups contained in the structure of the selected analytes was evaluated. Influence of parameters such as sample pH, nature of the water samples and derivatization conditions on the performance of the whole analytical procedure was systematically studied. Under optimal conditions, quantification limits between 1 and 3 ng/l were achieved for the determination of the considered estrogens in sewage water.


Assuntos
Estrogênios/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Resíduos Industriais
18.
J Chromatogr A ; 985(1-2): 265-74, 2003 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-12580494

RESUMO

A procedure is described for the determination of five acidic non-steroidal anti-inflammatory pharmaceuticals (ibuprofen, naproxen, ketoprofen, tolfenamic acid and diclofenac) in sewage water. The analytical method involves the concentration of water samples using a solid-phase extraction polymeric sorbent, functionalized with N-vinylpyrrolidone. Analytes were eluted with ethyl acetate. derivatized using N-methyl-N-(tert.-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) and analyzed by GC-MS. Influence of time, temperature and volume of MTBSTFA in the yield of the derivatization step were studied in detail using a factorial central composite design. Quantification limits of the analytical procedure for 500 ml of sewage water ranged from 20 to 50 ng/l. Recoveries from 90 to 115% were found for sewage water samples spiked with the studied compounds at the low ng/ml level. Results obtained for real samples show the presence of ibuprofen and naproxen in both influent and effluent of a sewage water treatment plant.


Assuntos
Anti-Inflamatórios não Esteroides/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Esgotos/química , Poluentes Químicos da Água/análise
19.
Spine (Phila Pa 1976) ; 21(3): 356-66, 1996 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-8742213

RESUMO

STUDY DESIGN: This study focused on lumbosacral support belts, abdominal muscle strength, and lifting ability in healthy women. Subjects underwent manual muscle testing to determine muscle strength and performed lifting procedures to determine lifting capacity. OBJECTIVES: The purpose of this study is threefold: 1) to determine the effectiveness of lumbosacral support belts in improving lifting ability in healthy women, 2) to determine if lumbosacral support belts are more effective for those with weak abdominals than those with strong abdominals, and 3) to determine if the maximum amount of weight varies with abdominal muscle strength. SUMMARY OF BACKGROUND DATA: In a review of published literature, one study has addressed the relationship of lumbosacral support belts and lifting capacity. However, no study has examined the use of lumbosacral support belts and lifting capacity in a female population. METHODS: A convenient sample of 69 healthy women, aged 20 to 40 years, participated in this study. Subjects were categorized into one of three groups based on lower and upper abdominal muscle strength. Each subject then performed two lifting procedures, one with a lumbosacral support belt and one without, to determine two maximum lifts. RESULTS: Women between the ages of 20 and 40 years could lift approximately 1.0 kg more weight from the floor to waist height with the lumbosacral support belt. The maximum weight lifted varied with abdominal strength. Lumbosacral support belts were not more effective for those with weak abdominals than those with strong abdominals. CONCLUSIONS: When applied properly and used in conjunction with proper lifting technique, lumbosacral support belts slightly improved lifting ability in healthy women. The magnitude of the increase, although statistically significant, is not sufficient to advocate the use of lumbosacral support belts to increase lifting capacity.


Assuntos
Músculos Abdominais/fisiologia , Remoção , Região Lombossacral , Aparelhos Ortopédicos , Adulto , Análise de Variância , Fenômenos Biomecânicos , Estudos de Avaliação como Assunto , Feminino , Humanos , Doenças Profissionais/prevenção & controle , Valores de Referência , Resistência à Tração/fisiologia
20.
Hosp Health Serv Adm ; 40(2): 278-95, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-10143036

RESUMO

High turnover rates among hospital nurses demand rigorous and valid processes of research to determine the reasons motivating such attrition. In most hospitals, the exit interview often provides the only relevant data. The case study reported here examines the relative effectiveness of exit interviews and an employee attitude survey in generating data that are useful in managing nurse retention. The conclusion reached is that the attitude survey generates more data and higher-quality data. Further, the study shows that the use of open-ended questions can provide useful information and probably should be the starting point in developing or supplementing an attitude survey for nurses. Recommendations for improving the usefulness and validity of nurse attitude surveys and exit interviews in managing nurse retention are provided.


Assuntos
Coleta de Dados/métodos , Satisfação no Emprego , Recursos Humanos de Enfermagem Hospitalar/psicologia , Reorganização de Recursos Humanos/estatística & dados numéricos , Atitude do Pessoal de Saúde , Coleta de Dados/normas , Emprego , Hospitais com 100 a 299 Leitos , Hospitais Públicos , Entrevistas como Assunto , Recursos Humanos de Enfermagem Hospitalar/estatística & dados numéricos , Avaliação de Programas e Projetos de Saúde/estatística & dados numéricos , Sudeste dos Estados Unidos , Recursos Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA