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1.
J Chromatogr A ; : 461038, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32199674

RESUMO

A QuEChERS method was optimized and validated for the LC-MS/MS analysis of perfluoro-n-pentanoic acid (PFPeA), perfluoro-1-butanesulfonic acid (PFBuS), perfluoro-n-hexanoic acid (PFHxA), perfluoro-n-heptanoic acid (PFHpA), perfluoro-1-hexanesulfonic acid (PFHxS), perfluoro-n-octanoic acid (PFOA), perfluoro-n-nonanoic acid (PFNA), perfluoro-1-octanesulfonic acid (PFOS) and perfluoro-n-decanoic acid (PFDA) in freeze-dried strawberry and olive, as model fruits characterized by very different chemical compositions. The method was evaluated for apparent recovery, intra-day and inter-day precision, matrix effect and recovery. The method optimized for strawberry provided for most compounds absolute values of matrix effect (|ME%|) ≤ 11%, except for PFHxA, which showed a signal suppression of 22%. The extraction efficiency was tested at the spike levels 500-5000 pg/g d.w. for PFPeA, PFBuS, and PFHxA, and 100-1000 pg/g d.w. for the other target analytes, evidencing as a whole recoveries in the range of 65-89%. For olive fruits, due to their high fat content, an ultrasound-assisted extraction was necessary to obtain an efficient sample disgregation so as to increase the extraction yield and its precision. Moreover, a d-SPE clean-up with GCB allowed to achieve |ME%| ≤ 8% (except for PFBuS, which showed a signal enhancement of 19%) and recoveries calculated at the aforementioned spike levels were in the range 75-97%. The two methods provided very good linearity (R2 ≥ 0.9984) from 10,000 pg/g down to compound specific quantification limits, which were included in the ranges of 2.9-393 pg/g and 2.6-127 pg/g for strawberry and olive fruit, respectively. The methods were applied to the analysis of PFAAs in strawberry and olive fruits commercially available in two Italian supermarkets, as well as obtained under irrigation with various treated wastewaters (TWWs), evidencing in both cases a higher PFAAs occurrence in olives than in strawberry. However, PFAAs concentrations determined in the investigated fruit matrixes were quite low, being their sum 1.9 ng/g d.w. in the worst case (i.e. olive fruits grown under irrigation with TWWs).

2.
J Chromatogr A ; 1611: 460615, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31630831

RESUMO

Nintedanib (NIN) is a tyrosine kinase inhibitor recently approved for the treatment of idiopathic pulmonary fibrosis. As a new drug, no monograph is available so far in official compendia. A liquid chromatography-tandem mass spectrometry method is presented for the simultaneous determination of NIN and its seven potential impurities. The risk-based approach of Analytical Quality by Design was applied in method development. The critical method parameters (CMPs) were the type of organic solvent in the mobile phase, formic acid percentage, column flow rate, oven temperature, gradient slope of organic eluent. The critical method attributes (CMAs) were selected as analysis time and selectivity between the main compound NIN and the adjacent peaks. Design of Experiments methodology was effectively employed for establishing the relationship between the CMPs and the CMAs. In the scouting step, a Restek Ultra AQ C18 (100 × 2.1 mm, 2.7 µm) core-shell column was selected, and then the effects of different levels of the five CMPs on the CMAs were evaluated by means of a 35//16 symmetric screening matrix. A Box-Behnken Design made it possible to obtain detailed maps of predicted CMAs throughout the investigated experimental domain, pointing out the presence of interaction and quadratic effects. The probability of meeting the specifications for the CMAs was calculated by Monte-Carlo simulations, performing a risk analysis and drawing risk of failure maps, which were used to visualize and define the method operable design region (MODR) with a probability π ≥ 90%. The final working conditions (enclosing the MODR interval) were as follows: methanol as organic solvent; formic acid percentage, 0.15% v/v; flow rate, 0.40 mL min-1 (0.37-0.43 mL min-1); oven temperature, 40 °C (38-40 °C); gradient slope of organic eluent, 14.00% eluent B min-1 (12.85-15.15% eluent B min-1). The resulting analysis time was about 10 min. Validation was carried out according to International Council for Harmonisation guidelines and the optimized method was applied to the analysis of NIN soft capsules for quality control purposes.

3.
Sci Total Environ ; 708: 135217, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31810702

RESUMO

Three biochars were produced using sawdust from waste biomass, via a simple pyrolysis thermal conversion at 450, 650, and 850 °C (BC450, BC650, and BC850), without any activation process. These materials, together with vegetal and mineral commercial activated carbons (VAC and MAC), were characterized for their elemental composition, Brunauer-Emmett-Teller surface area, t-plot microporosity and Barrett-Joyner-Halenda mesoporosity. Moreover, iodine, phenol and methylene blue porosity indexes were measured. The materials were also evaluated for their pH of the point of zero charge, as well as near-surface chemical composition and surface functionality by means of X-ray photoelectron and Fourier-transform infrared spectroscopy. Ash content, water-extractable metals and polycyclic aromatic hydrocarbons (PAHs) were also determined. BC650 showed a much higher surface area (319 m2 g-1) compared to BC450 (102 m2 g-1), as well as an increase in aromatization and the residual presence of functional polar groups. BC850 exhibited a loss of polar and aromatic groups, with the dominance of graphitic carbon and the highest value of surface area (419 m2 g-1). Biochars comply with the EN 12915-1/2009 limits for metal and PAH release in water treatment. Biochars and MAC were tested using Langmuir and Freundlich isotherms for the sorption in real effluent wastewater of a mixture of 14 branched ethoxylated 4-t-octyl and 4-nonylphenols, as well as 4-t-octyl and 4-nonylphenol, the latter representing persistent, endocrine disrupting contaminants, widespread in the effluents from wastewater treatment plants and listed as priority/priority hazardous substances in the Directive 2013/39/EU. Biochars showed a lower sorption efficiency compared to MAC. The best performance was found for BC650 towards the alkylphenols (9-13 times less efficient than the MAC). Considering the lower market price of biochar compared to MAC (estimated as at least 16 times less expensive by a small market survey), the former can be considered more competitive than the latter.

4.
Chemosphere ; 238: 124651, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31472346

RESUMO

A harbour sediment, previously remediated, was tested for soilless strawberry cultivation (Camarosa and Monterey cultivars), as an innovative, cost-effective and environment-friendly approach of sediment management. Sediments were tested as such (TS100) and mixed 1/1 (v/v) with a peat-based commercial substrate (TS50), using the peat-based medium as control (TS0). Substrates were characterized for some physicochemical properties (e.g. density, porosity and water capacity). Minerals (P, Ca, K, Na and Fe), heavy metals (Cu, Zn, Mn, Ni, Cr, Pb and Cd), aliphatic hydrocarbons (C > 12), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dibenzodioxins and dibenzofurans were analysed in substrates and fruits. Sugars and organic acids, including the ascorbic, were also determined in fruits, as quality indicators. Notwithstanding remediation, sediments showed concentrations of Zn (206 mg kg-1), C > 12 (86 mg kg-1) and PAHs (47 mg kg-1) exceeding the limits established by the Italian L.D. 152/2006, regulating the contamination of soil in green areas, thus making its relocation in the environment not permitted as such. No evidence of fruit contamination by Cr, Pb and Cd was highlighted. Moreover, Cu, Zn and Ni fruit concentrations were comparable among treatments. Conversely, Mn showed statistically higher concentrations in TS0 fruits (56-57 mg kg-1) compared to those grown in sediment-based substrates (8-20 mg kg-1). Among organic contaminants, only dioxin-like PCBs were determined in fruits, at toxic equivalent concentrations fourfold lower than the limit established by the European Union. TS100 fruits showed a yield reduction from 40 to 70% for Camarosa and Monterey, but higher sugar and ascorbic acid contents.


Assuntos
Produtos Agrícolas/normas , Monitoramento Ambiental , Fragaria/metabolismo , Frutas/química , Sedimentos Geológicos/química , Produtos Agrícolas/química , Produtos Agrícolas/crescimento & desenvolvimento , Fragaria/química , Itália , Metais Pesados/análise , Minerais/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/química
5.
J AOAC Int ; 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31530340

RESUMO

Background: Domestic and industrial wastewater can be introduced in a reuse chain for irrigation purposes. Objective: In this paper, we developed analytical procedures for the extraction of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) along a wastewater reuse chain for irrigation purposes. Besides urban wastewaters, olive mill wastewater (OMWW) was considered as a potential water source. Wastewaters were purified by different treatments (urban wastewater plants, pilot-activated sludge, and constructed wetland) and used for the irrigation of olive trees. Suitable extraction procedures were used to analyze treated and untreated wastewaters, soils, and postirrigation leachates. Results: For wastewater and leachate samples, the optimized reverse-phase solid-phase extraction (SPE) provided recoveries up to 79%. For OMWW, the SPE procedure was preceded by a normal-phase purification stage with silica gel for the removal of polyphenols, which were as high as 8.7 g/L. After optimization, extraction recoveries in blank solutions were in the range 20-67% and moderately reduced (10-38%) in OMWW as a result of the matrix effect (ME; -10/-60%) ascribed to the very high value of chemical oxygen demand (264 g/L). LODs of the method were below 1.1 µg/L (PAHs) and 3.2 µg/L (PCBs) using GC-MS analysis. For soil samples of different compositions, microwave-assisted extraction (MAE) provided better extraction recoveries and reproducibility than the more common quick, easy, cheap, effective, rugged, and safe approach, which was affected by a high ME. The LODs of the MAE/GC-MS method were below 4.9 µg/kg (PAHs) and 12.3 µg/kg (PCBs). Conclusions: The analytical procedures developed are a valuable tool to quantify the possible propagation of residual contamination from PAHs/PCBs with irrigation along the wastewater reuse chain.

6.
J Pharm Biomed Anal ; 173: 1-17, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31100508

RESUMO

An ultrahigh performance liquid chromatography tandem mass spectrometry method (UHPLC-MS/MS) was developed for the determination of 41 target and 8 additional bile acids isomers (BAs) in biological fluids. BAs were analysed by solid-phase extraction on 50 µL biofluid-aliquots, followed by a properly optimised 27 min-chromatographic run. The method provided high sensitivity (limits of detection 0.0002-0.03 µM, limits of quantitation 0.0007-0.11 µM), linearity (R2>0.99) and precision (relative standard deviations ≤16%). A strategy of scheduled/ unscheduled injections of real samples together with neutral loss (80 Da and 176 Da) scans allowed us to find additional bile acid isomers not a priori included in the method, while high resolution full scan and MS/MS fragmentation analysis confirmed their structural adherence to the bile acid family. Moreover this is the first study quantifying four sulfate glycine conjugated-dihydroxy bile acid isomers, independently of the diet and postprandial time. Application to a dietary intervention kinetic study confirmed the existence of possible metabotypes amongst the study population (n = 20). A trend differentiating males from females was observed suggesting that serum samples from women contained smaller amounts of certain bile acids.


Assuntos
Ácidos e Sais Biliares/sangue , Glucuronídeos/sangue , Glicina/sangue , Técnica de Diluição de Radioisótopos , Ácidos e Sais Biliares/química , Radioisótopos de Carbono , Cromatografia Líquida de Alta Pressão/métodos , Jejum/sangue , Feminino , Glucuronídeos/química , Glicina/química , Humanos , Limite de Detecção , Masculino , Período Pós-Prandial , Reprodutibilidade dos Testes , Fatores Sexuais , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos
7.
Sci Total Environ ; 674: 36-48, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31003086

RESUMO

In this work the occurrence and fate of polycyclic aromatic hydrocarbons (PAHs), phthalic acid esters (PAEs), mono and diethoxylate alkylphenols (AP1-2EOs) and alkylphenols (APs) have been investigated during a two-weeks period in a facility treating mixed textile-domestic wastewater (Prato, Italy). The wastewater treatment plant (WWTP) consists of primary sedimentation, activated sludge biological oxidation, secondary sedimentation, clariflocculation and ozonation. The sludge is treated within the facility by thickening, dewatering and final incineration, thus providing the almost quantitative removal of the adsorbed micropollutants. Naphthalene (50%), di(2-ethylhexyl) phthalate (74%) and branched 4-nonylphenols (59%) were the individual main representative compounds of each class in the influent wastewater, which showed concentration ranges of 5.6-66, 85-290 and 21-133µg/L for PAHs, PAEs and APs+AP1-2EOs, respectively. The WWTP efficiently removed PAHs, PAEs and APs+AP1-2EOs, providing effluent concentrations of 0.075-0.16ng/L 0.38-9.9µg/L and 0.53-1.4µg/L. All targeted priority and priority-hazardous micropollutants showed effluent concentrations in line with the European environmental quality standards (EQS), even though for di(2-ethylhexyl) phthalate and benzo(a)pyrene after correction for the dilution factor of the recipient. The WWTP performance was evaluated by mass balance, verifying its accuracy by monitoring Pb and Cd as conservative species. The biological treatment sections provided mass losses of 85.5%, 74.5% and 56.8% for APs+AP1-2EOs, PAEs and PAHs, highlighting efficient biotransformation performances of the activated sludge process. However, for the more volatile PAHs (e.g. naphthalene), a significant contribution of stripping cannot be excluded. A remarkable mass loss was also determined in the ozonation stage for PAEs (72.9%) and especially PAHs (97.0%), whereas a lower efficiency was observed for APs+AP1-2EOs (41.3%). The whole plant allowed for obtaining an almost quantitative removal (96.7-98.4%) for all targeted compounds.

8.
Water Sci Technol ; 79(1): 145-155, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30816871

RESUMO

In this paper, the design and start-up of a constructed wetland (CW) for the tertiary treatment of landfill leachates is presented. The flux is characterized by high salinity, high concentration of nitrogen (almost completely in the form of nitrate) and a biochemical oxygen demand (BOD)/chemical oxygen demand (COD) ratio close to zero. The CW pilot plant suffered from mechanical and hydraulic malfunctions which led to an uneven growth of plants inside the tanks. Despite this, COD has been reduced in the range of 0-30%, reduced forms of N (ammonia and nitrite) are also oxidized and removed by 50-80% and 20-26% on average. Considering the low number of plants and the loading rate, CW pilot plant allowed to remove more than 16 kg of COD, leading to a specific removal of 10 gCOD/d · m2. Moreover, bacterial communities associated to plants were isolated and analyzed in order to evaluate the influence of such communities on phytoremediation. Bulk soil registered the lowest bacterial titers, while plant compartments and rhizospheric soil showed to be more suitable for bacterial colonization. Twenty-five different bacterial genera were observed among the analyzed isolates, with the predominance of Pseudomonas genus.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , Áreas Alagadas , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Nitrogênio , Poluentes Químicos da Água/análise
9.
J Pharm Biomed Anal ; 166: 326-335, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30685656

RESUMO

Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC) are considered as the most interesting cannabinoids in Cannabis sativa L. for the clinical practice. Since 2013, the Italian law allows pharmacists to prepare and dispense cannabis extracts to patients under medical prescription, and requires the evaluation of CBD and Δ9-THC content in cannabis extracts before sale. Cannabis olive oil extracts are prepared from dried female cannabis inflorescences, but a standard protocol is still missing. In this study, a fast RP-HPLC/UV method has been developed to quantify CBD and Δ9-THC in cannabis olive oil extracts. The analytical quality by design strategy has been applied to the method development, setting critical resolution and total analysis time as critical method attributes (CMAs), and selecting column temperature, buffer pH and flow rate as critical method parameters. Information from Doehlert Design in response surface methodology combined to Monte-Carlo simulations led to draw the risk of failure maps and to identify the method operable design region. The method was validated according to the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines and then implemented in routine analysis. A control strategy based on system control charts was planned to monitor the developed method performances. Evaluation data were recorded over a period of one year of routine use, and both the CMAs showed values within the specifications in every analysis performed. Hence, a new risk evaluation for the future performances of the method was achieved by using a Bayesian approach based on the routine use data, computing the future distribution of the two CMAs. Finally, a study focusing on the monitoring of CBD and Δ9-THC concentrations in cannabis olive oil extracts was carried out. The developed method was applied to 459 extracts. The statistical analysis of the obtained results highlighted a wide variability in terms of concentrations among different samples from the same starting typology of cannabis, underlining the compelling need of a standardised procedure to harmonise the preparation of the extracts.


Assuntos
Canabidiol/análise , Cannabis/química , Dronabinol/análise , Maconha Medicinal/análise , Azeite de Oliva/química , Extratos Vegetais/química , Projetos de Pesquisa/normas , Teorema de Bayes , Cromatografia Líquida de Alta Pressão , Itália , Reprodutibilidade dos Testes
10.
J Am Soc Mass Spectrom ; 30(3): 381-402, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30506347

RESUMO

In this work, liquid chromatography, coupled with an electrospray ionization hybrid linear ion trap quadrupole/Orbitrap mass spectrometry, has been used to accurately identify polyphenol metabolites in human serum and urine after acute ingestion of a V. myrtillus berry supplement. The supplement was obtained by cryo-milling of bilberries, which were freeze-dried within 1 week after their harvesting, to maintain the berry native composition. Thirty-six derivatives of benzoic acids, hydroxyhippuric acids, cinnamic acids, phenylpropionic acids, phenylvaleric acids, phenylpentenoic acids and abscisic acid, together with two berry-native anthocyanins, one flavonol metabolite and two catechol derivatives were putatively identified in the investigated biofluids. The annotated compounds included 13 metabolites, among glucuronides and sulphates of phenylvaleric and phenylpentenoic acids, which have been identified for the first time in human biofluids after ingestion of V. myrtillus berries. It should be emphasized that the presence of phenylvaleric and phenylpentenoic acid derivatives is in agreement with their origin from fruit native flavanol monomers and oligomers, which are widely distributed in Vaccinium berries, but usually overlooked in metabolomics studies regarding bilberry. The identification of these compounds confirmed the key-role of untargeted metabolomics approach in the discovery of new metabolites which could be biologically active. Graphical Abstract.


Assuntos
Cromatografia Líquida/métodos , Polifenóis/sangue , Polifenóis/urina , Espectrometria de Massas por Ionização por Electrospray/métodos , Vaccinium myrtillus , Adulto , Suplementos Nutricionais , Frutas , Humanos , Metabolômica/métodos , Polifenóis/metabolismo , Espectrometria de Massas em Tandem/métodos
11.
J Chromatogr A ; 1568: 205-213, 2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30005942

RESUMO

A capillary electrophoresis method for the simultaneous determination of the enantiomeric purity and of impurities of the chiral calcimimetic drug cinacalcet hydrochloride has been developed following Quality by Design principles. The scouting phase was aimed to select the separation operative mode and to identify a suitable chiral selector. Among the tested cyclodextrins, (2-carboxyethyl)-ß-cyclodextrin and (2-hydroxypropyl)-γ-cyclodextrin (HPγCyD) showed good chiral resolving capabilities. The selected separation system was solvent-modified capillary zone electrophoresis with the addition of HPγCyD and methanol. Voltage, buffer pH, methanol concentration and HPγCyD concentration were investigated as critical method parameters by a multivariate strategy. Critical method attributes were represented by enantioresolution and analysis time. A Box-Behnken Design allowed the contour plots to be drawn and quadratic and interaction effects to be highlighted. The Method Operable Design Region (MODR) was identified by applying Monte-Carlo simulations and corresponded to the multidimensional zone where both the critical method attributes fulfilled the requirements with a desired probability π≥90%. The working conditions, with the MODR limits, corresponded to the following: capillary length, 48.5cm; temperature, 18°C; voltage, 26kV (26-27kV); background electrolyte, 150mM phosphate buffer pH 2.70 (2.60-2.80), 3.1mM (3.0-3.5mM) HPγCyD; 2.00% (0.00-8.40%) v/v methanol. Robustness testing was carried out by a Plackett-Burman matrix and finally a method control strategy was defined. The complete separation of the analytes was obtained in about 10min. The method was validated following the International Council for Harmonisation guidelines and was applied for the analysis of a real sample of cinacalcet hydrochloride tablets.


Assuntos
Cinacalcete/química , Cinacalcete/isolamento & purificação , Eletroforese Capilar/métodos , Contaminação de Medicamentos , Concentração de Íons de Hidrogênio , Método de Monte Carlo , Probabilidade , Medição de Risco , Solventes , Estereoisomerismo , beta-Ciclodextrinas/química , gama-Ciclodextrinas/química
12.
Sci Total Environ ; 633: 405-425, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29579652

RESUMO

Contamination of the aquatic environment caused by multiple human activities may exert a negative impact on all living organisms. Several contaminants of emerging concern such as personal care products (PCPs) are continuously released into the aquatic environment where they are biologically active and persistent. This work reviews the current knowledge, provided by papers published after 2010 and indexed by SciFinder, Scopus, and Google search engines, about the determination and occurrence of PCPs in marine biota. Analytical methodologies have been critically reviewed, emphasizing the importance of green and high-throughput approaches and focusing the discussion on the complexity of the solute-matrix interaction in the extraction step, as well as the matrix effect in the instrumental determination. Finally, the worldwide distribution of PCPs is surveyed, taking into account the concentrations found in the same organism in different marine environments. Differences among various world areas have been highlighted, evidencing some critical aspects from an environmental point of view.


Assuntos
Organismos Aquáticos/metabolismo , Cosméticos/análise , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Organismos Aquáticos/química , Cosméticos/metabolismo , Poluentes Químicos da Água/metabolismo , Poluição Química da Água/análise
13.
Environ Sci Pollut Res Int ; 25(11): 10619-10629, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29383645

RESUMO

The presence of residual color in treated textile wastewater above the regulation limits is still a critical issue in many textile districts. Innovative, polymer-derived ceramics of the Si-C-O system were here synthesized in order to obtain porous nanocomposite materials where a free carbon phase is dispersed into a silicon carbide/silicon oxycarbide network. The sorbents were comprehensively characterized for the removal of two model water-soluble dyes (i.e., the cation methylene blue and the zwitterion rhodamine B). Adsorption is very rapid and controlled by intra-particle and/or film diffusion, depending on dye concentration. Among the nanocomposites studied, the SiOC aerogel (total capacity about 45 mg/g, is easily regenerated under mild treatment (250 °C, 2 h). Adsorption of dyes is not affected by the matrix composition: removals of 150 mg/L methylene blue from river water and simulated textile wastewater with high content of metal ions (2-50 mg/L) and chemical oxygen demand (800 mg/L) were higher than 92% and quantitative for a dye concentration of 1 mg/L.


Assuntos
Carbono/química , Corantes/química , Azul de Metileno/química , Nanocompostos/química , Polímeros/química , Rodaminas/química , Adsorção , Análise da Demanda Biológica de Oxigênio , Cerâmica , Porosidade , Silício , Indústria Têxtil , Têxteis , Águas Residuárias
14.
Talanta ; 176: 412-421, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28917770

RESUMO

The applicability of a direct injection UHPLC-MS/MS method for the analysis of several perfluoroalkyl acids (PFAAs) in a wide range of water matrices was investigated. The method is based on the direct injection of 100µL of centrifuged water sample, without any other sample treatment. Very good method detection limits (0.014-0.44ngL-1) and excellent intra and inter-day precision (RSD% values in the range 1.8-4.4% and 2.7-5.7%, respectively) were achieved, with a total analysis time of 20min per sample. A high number of samples - i.e. 8 drinking waters (DW), 12 ground waters (GW), 13 surface waters (SW), 8 influents and 11 effluents of wastewater treatment plants (WWTPIN and WWTPOUT) were processed and the extent of matrix effect (ME) was calculated, highlighting the strong prevalence of |ME| < 20%. The occurrence of |ME| > 50% was occasionally observed only for perfluorooctanesulphonic and perfluorodecanoic acids. Linear discriminant analysis highlighted the great contribution of the sample origin (i.e. DW, GW, SW, WWTPIN and WWTPOUT) to the ME. Partial least square regression (PLS) and leave-one-out cross-validation were performed in order to interpret and predict the signal suppression or enhancement phenomena as a function of physicochemical parameters of water samples (i.e. conductivity, hardness and chemical oxygen demand) and background chromatographic area. The PLS approach resulted only in an approximate screening, due to the low prediction power of the PLS models. However, for most analytes in most samples, the fitted and cross-validated values were such as to correctly distinguish between | ME | higher than 20% or below this limit. PFAAs in the aforementioned water samples were quantified by means of the standard addition method, highlighting their occurrence mainly in WWTP influents and effluents, at concentrations as high as one hundred of µgL-1.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ácidos Graxos/análise , Fluorcarbonetos/análise , Ácidos Sulfônicos/análise , Espectrometria de Massas em Tandem/métodos , Poluentes Químicos da Água/análise , Água Potável/análise , Monitoramento Ambiental , Água Doce/análise , Limite de Detecção , Águas Residuárias/análise
15.
J Pharm Biomed Anal ; 148: 6-16, 2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-28946042

RESUMO

A sensitive and reliable analytical method was developed for the simultaneous determination of five phthalate diesters and corresponding monoesters in human milk samples and infant formulas. The method involved a liquid-liquid extraction with a CH2Cl2/CH3OH/NaCl 30% 2/1/0.5 (v/v/v) mixture, the clean-up of the extract by size-exclusion chromatography (swelling and elution solvent: cyclohexane/ethyl acetate 9/1v/v), the derivatization of monoesters by trimethylsilyl-diazomethane and instrumental analysis by gas chromatography coupled with mass spectrometry. Recovery was in the range of 83-115% and precision was found between 9% and 21%. For phthalate diesters, method detection limits (MDLs) ranged from hundreds of ng/kg to 4.2µg/kg on a fresh weight milk (f.w.) basis, depending on blank contribution evaluated in matrix. Lower MDLs (0.03-0.8µg/kg f.w.) were achieved for corresponding monoesters. The proposed method was applied to the determination of target compounds in nine human milk samples and four infant formulas, confirming their presence in all samples. However, a generally higher contamination was assessed in artificial milk than in breast milk samples.


Assuntos
Ésteres/química , Fórmulas Infantis/análise , Leite Humano/química , Ácidos Ftálicos/química , Cromatografia em Gel/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Recém-Nascido , Limite de Detecção , Extração Líquido-Líquido/métodos
16.
Environ Sci Pollut Res Int ; 25(2): 1331-1339, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29086177

RESUMO

This work investigated if the assessment of tolerance to trace metals can depend on plant density in the experimental design. A non-metallicolous and a metallicolous populations of Silene paradoxa were hydroponically cultivated at increasing density and in both the absence (-Cu conditions) and excess of copper (+Cu conditions). In -Cu conditions, the metallicolous population showed a lower susceptibility to plant density in comparison to the non-metallicolous one, explained by a higher capacity of the metallicolous population to exploit resources. In +Cu conditions, an alleviating effect of increasing density was found in roots. Such effect was present to a greater extent in the non-metallicolous population, thus making the populations equally copper-tolerant at the highest density used. In shoots, an additive effect of increasing plant density to copper toxicity was reported. Its higher intensity in the metallicolous population reverted the copper tolerance relationship at the highest plant densities used. In both populations, a density-induced decrease in root copper accumulation was observed, thus concurring to the reported mitigation in +Cu conditions. Our work revealed the importance of density studies on the optimization of eco-toxicological bioassays and of metal tolerance assessment and it can be considered the first example of an alleviating effect of increasing plant number on copper stress in a metallophyte.


Assuntos
Cobre/toxicidade , Silene/efeitos dos fármacos , Poluentes do Solo/toxicidade , Hidroponia , Itália , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/fisiologia , Densidade Demográfica , Silene/fisiologia
17.
Talanta ; 178: 552-562, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29136861

RESUMO

Bexsero is the first approved vaccine for active immunization of individuals from 2 months of age and older to prevent invasive disease caused by Neisseria meningitidis serogroup B. The active components of the vaccine are Neisseria Heparin Binding Antigen, factor H binding protein, Neisseria adhesin A, produced in Escherichia coli cells by recombinant DNA technology, and Outer Membrane Vesicles (expressing Porin A and Porin B), produced by fermentation of Neisseria meningitidis strain NZ98/254. All the Bexsero active components are adsorbed on aluminum hydroxide and the unadsorbed antigens content is a product critical quality attribute. In this paper the development of a fast, selective and sensitive ultra-high-performance liquid chromatography (UHPLC) method for the determination of the Bexsero antigens in the vaccine supernatant is presented. For the first time in the literature, the Quality by Design (QbD) principles were applied to the development of an analytical method aimed to the quality control of a vaccine product. The UHPLC method was fully developed within the QbD framework, the new paradigm of quality outlined in International Conference on Harmonisation guidelines. Critical method attributes (CMAs) were identified with the capacity factor of Neisseria Heparin Binding Antigen, antigens resolution and peak areas. After a scouting phase, aimed at selecting a suitable and fast UHPLC operative mode for the vaccine antigens separation, risk assessment tools were employed to define the critical method parameters to be considered in the screening phase. Screening designs were applied for investigating at first the effects of vial type and sample concentration, and then the effects of injection volume, column type, organic phase starting concentration, ramp time and temperature. Response Surface Methodology pointed out the presence of several significant interaction effects, and with the support of Monte-Carlo simulations led to map out the design space, at a selected probability level, for the desired CMAs. The selected working conditions gave a complete separation of the antigens in about 5min. Robustness testing was carried out by a multivariate approach and a control strategy was implemented by defining system suitability tests. The method was qualified for the analysis of the Bexsero vaccine.


Assuntos
Antígenos de Bactérias/análise , Proteínas de Bactérias/análise , Vacinas Meningocócicas/análise , Porinas/análise , Cromatografia Líquida de Alta Pressão , Neisseria meningitidis Sorogrupo B , Controle de Qualidade
18.
J Pharm Biomed Anal ; 149: 249-257, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29127906

RESUMO

An integrated approach involving CE experiments, Molecular Dynamics (MD) simulations and two-dimensional NOE spectroscopy (2D-NOESY) experiments was employed to elucidate the intermolecular interactions and the separation mechanisms involved in a solvent-modified MEKC method for the simultaneous determination of diclofenac sodium and its impurities. The CE findings indicated that the addition of n-butanol (nBuOH) to the SDS micellar solution played a primary role for controlling the partitioning into the mixed micelles and the migration of the analytes and that the presence of nBuOH as cosurfactant was compulsory for achieving the complete separation of the compounds. The different capacity factors of the analytes were calculated and a change in solute association with the mixed micelle when changing the SDS/nBuOH molar ratio was highlighted. The optimal SDS/nBuOH molar ratio for the electrophoretic separation was 1:8. On the other hand, both MD simulations and NMR experiments indicated that the most favorable molar ratio for the formation of mixed SDS/nBuOH micelles was 1:2. These results suggested that probably there is an excess of nBuOH in the background electrolyte, both as free molecules and in form of aggregates, which is able to interact with the analytes, and thus may compete with mixed micelles for the considered compounds. The calculated values of gain in potential energy of the analytes when included in mixed micelles were in agreement with the observed migration order of the compounds. The role of methyl-ß-cyclodextrin (MßCyD) in the background electrolyte was also investigated, since the addition of this CyD to the solvent-modified MEKC system was found to be useful to reduce the analysis time. MD simulations and 2D-NOESY spectra highlighted the formation of inclusion complexes with MßCyD not only with the analytes, but also with SDS. MßCyD may lower the availability of both SDS and nBuOH for forming micelles and mostly may compete with the mixed micelle as a second pseudostationary phase.


Assuntos
1-Butanol/química , Anti-Inflamatórios não Esteroides/química , Fracionamento Químico/métodos , Diclofenaco/química , Fracionamento Químico/instrumentação , Cromatografia Capilar Eletrocinética Micelar/instrumentação , Cromatografia Capilar Eletrocinética Micelar/métodos , Composição de Medicamentos , Contaminação de Medicamentos/prevenção & controle , Eletrólitos , Espectroscopia de Ressonância Magnética/instrumentação , Espectroscopia de Ressonância Magnética/métodos , Micelas , Simulação de Dinâmica Molecular , Solventes/química , Tensoativos/química
19.
J Pharm Biomed Anal ; 144: 220-229, 2017 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-28131522

RESUMO

A comprehensive investigation on the CE separation mechanisms and on the inclusion complexation with CyDs of the chiral drug S-ambrisentan (S-AMB), its R-enantiomer and other impurities was performed by different techniques. A CE method was previously set up allowing the simultaneous determination of the enantiomeric purity and of impurities of S-AMB, based on the addition of SDS micelles and γ-cyclodextrin (γCyD) to borate buffer. In this study, the electrophoretic behavior of the analytes in terms of selectivity and mobility with respect to the addition of different CyDs was first investigated, evidencing the presence of interactions for all the CyDs, but the unique ability of γCyD for obtaining the separation of all the compounds. By molecular modeling, aggregates between SDS micelles and analytes, and inclusion complexes between CyDs, SDS and/or analytes of different stoichiometries were simulated. The potential and the gain energy of complexes were calculated on the minimized conformations, showing the great tendency of γCyD of forming mixed complexes with one or two SDS molecules and with the analyte, even if with different affinities among the analytes. For 1:1:1 mixed complexes with different CyDs, the highest difference of potential energy between the enantiomers' complexes was observed for γCyD. Two-dimensional NOE spectroscopy experiments were performed for S-AMB and I1 and pointed out the interactions of the aromatic moiety of the analytes and of SDS aliphatic chain with γCyD protons, confirming the existence of γCyD mixed complexes. The high affinity of SDS for the γCyD cavity was suggested to justify the fundamental role of SDS in modulating and achieving the CE separation, due to its influence both on the stability and on the type of complexes between γCyD and the analytes.


Assuntos
Eletroforese Capilar , Espectroscopia de Ressonância Magnética , Ciclodextrinas , Fenilpropionatos , Piridazinas , Estereoisomerismo
20.
Anal Bioanal Chem ; 409(5): 1347-1368, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27847974

RESUMO

Ultra-high-performance liquid chromatography coupled with high-resolution quadrupole-time of flight mass spectrometry with both negative and positive ionization was used for comprehensively investigating the phenolic and polyphenolic compounds in berries from three spontaneous or cultivated Vaccinium species (i.e., Vaccinium myrtillus, Vaccinium uliginosum subsp. gaultherioides, and Vaccinium corymbosum). More than 200 analytes, among phenolic and polyphenolic compounds belonging to the classes of anthocyanins, monomeric and oligomeric flavonols, flavanols, dihydrochalcones, phenolic acids, together with other polyphenolic compounds of mixed structural characteristics, were identified. Some of the polyphenols herein investigated, such as anthocyanidin glucuronides and malvidin-feruloyl-hexosides in V. myrtillus, or anthocyanindin aldopentosides and coumaroyl-hexosides in V. uliginosum subsp. gaultherioides and a large number of proanthocyanidins with high molecular weight in all species, were described for the first time in these berries. Principal component analysis applied on original LC-TOF data, acquired in survey scan mode, successfully discriminated the three Vaccinium berry species investigated, on the basis of their polyphenolic composition, underlying one more time the fundamental role of mass spectrometry for food characterization.


Assuntos
Cromatografia Líquida/métodos , Polifenóis/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Vaccinium/química
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