The non-thermal plasma (NTP) technique is an advanced oxidation technology (AOT) applied to the degradation of organic compounds in water. In this study, the degradation kinetics of indigo carmine ...was investigated systematically, applying N2-NTP, O2-NTP, ozonolysis and hydrogen peroxide and the results were compared. The transient species (OH, O and NO radicals) formed with the NTP discharge at the gas-liquid interface and their products (NO3−, NO2−, H2O2) stabilized by the water, were identified and quantified. These species contribute to the effects on the chemical characteristics of the water, such as a decrease in the pH and increase in the conductivity and redox potential. Additionally, the stabilization of the oxidative species was estimated from the degradation reactions induced by the post-discharge effect, which was significant in the case of N2-NTP, due to the presence of long-lived species, such as nitrite and nitrate. The kinetics study revealed first-order kinetics for IC color removal and the rate constant values followed the order: O2-NTP (3.0 × 10−1 min−1) > O3 (1.4 × 10−1 min−1) > N2-NTP (2.2 × 10−2 min−1) > H2O2 (negligible). Also the main by-products of N2-NTP, O2-NTP and ozonolysis degradation reaction were identified by ultra-fast liquid chromatography coupled with mass spectrometry. The route fragmentation showed the formation of indole intermediates, such as isatin, which is an important precursor in organic synthesis.
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•The species OH.• and NO• formed with the NTP discharge were identified•Degradation rate as follows: O2-NTP > O3 >, N2-NTP > H2O2.•Post-discharge effect was significant for N2-NTP.•IC degradation by-products identified were similar for O2-NTP, O3 and N2-NTP.
•A rapid CZE method for the analysis ofcitrate, phosphate and sulfitewas developed.•The analytes were separated in less than 3.5 min.•Seafood samples were analyzed by the validated CZE ...method.•In-house method validation was performed to confirm the fitness-for-purpose.
Since seafood is susceptible to decomposition, additives may be used to maintain its quality. However, some additives may be improperly used to disguise spoilage, thus resulting in food fraud. Market growth demands faster and more reliable quality control tools that incorporate the most common additives in a single analysis. This study developed a rapid analytical method for the determination of citrate, phosphate and sulfite in seafood by capillary zone electrophoresis with indirect UV–Vis detection. Electrophoretic separation was achieved in less than 3.5 min. The background electrolyte consisted of 20 mmol L−1 of benzenesulfonic acid and 45 mmol L−1 of aminocaproic acid. After validation, the method was applied for 24 seafood real samples. Citrate was found in five samples. Four samples presented higher phosphate and sulfite concentrations than those permitted by Brazilian legislation. Good analytical performance indicates that the method is a viable alternative for food control in routine analysis.
Alzheimer's disease and diabetes mellitus are contemporary diseases of great concern. Phenolic compounds are linked to several health benefits and could lead to novel strategies to combat these ...ailments. The objective of this study was to evaluate by electrophoretically-mediated microanalysis the potential inhibitory activity of the fruit juices from Plinia cauliflora ("jaboticaba") and Eugenia uniflora ("pitanga") toward acetylcholinesterase (AChE) and α-glucosidase, target enzymes in strategies for the treatment of these diseases. The phenolic profiles of the samples were also investigated. Jaboticaba and pitanga juices inhibited 85.90 ± 1.73 and 52.67 ± 1.24% of AChE activity at 5 mg mL
−1
, and 57.91 ± 2.60 and 69.47 ± 2.89% of α-glucosidase activity at 1 mg mL
−1
, respectively. Total phenolic content of the juices were 303.54 ± 28.28 and 367.00 ± 11.42 mgGA L
−1
, respectively. The observed inhibitory activity can be explained, at least in part, by the presence of the phenolic compounds.
•An ion-pair LC–MS/MS method for polar vet drug residues was proposed.•Different LC approaches were assessed.•Method validation was in accordance to Commission Decision 657/2002/CE.•Method ...applicability showed its fit-for-purpose.•Zilpaterol and halquinol were quantitated in four of 20 samples.
A method for the simultaneous analysis of veterinary drug residues (spectinomycin, halquinol, and zilpaterol) and contaminants (melamine) in feedingstuffs by liquid chromatography–tandem mass spectrometry was developed. Method performance for all analytes was evaluated by reversed-phase liquid chromatography, reversed-phase with altered chemical equilibrium, and hydrophilic interaction (HILIC) as chromatographic modes. Validation was in accordance to Commission Decision 657/2002/CE, by considering the best chromatographic approach. Ion-pair liquid chromatography with C18 as stationary phase led to the lowest random uncertainties, effective analyte separation and shorter time of analysis. Low precision deviations and good recovery rates were obtained and thus method reliability and sensitivity could be consolidated. Method applicability was evaluated by the analysis of samples of feedingstuffs, such as cattle, pig, and poultry feeds, feed ingredients of both animal and vegetable origins, and mineral feeds. Some samples showed quantifiable concentrations of halquinol and zilpaterol, reinforcing the importance of this new analytical control method.
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•An alternative CZE method was developed for the inspection of sulfite in seafood.•CZE method use simple instrumentation and separation occurs in less than 3 min.•Simultaneous ...extraction/derivatization step requires only 30 min.•The instability of the sulfite was suppressed by its derivatization with formaldehyde.•Full validation confirmed method fitness for application in seafood.
Sulfite is widely used to prevent enzymatic browning in shrimp and lobster processing. However, sulfite may cause allergy in sensitive consumers. Thus, regulatory agencies set limits for its use. Sulfite is usually controlled by the normalized Monier-Williams (MW) titrimetric method that allows a limited number of samples to be analyzed. This manuscript consolidates an innovative method for sulfite inspection in seafood by capillary zone electrophoresis with diode array detector (CZE-DAD). A simple, fast, and simultaneous extraction and derivatization method was developed to provide high throughput for analytical routine. The high instability of the sulfite was suppressed by its derivatization with formaldehyde producing hydroxymethylsulfonate. The evaluation of its analytical performance yielded excellent results in compliance with the strict parameters required for metrological accreditation. The CZE-DAD method was selective and specific when submitted to confirmatory evaluations by liquid chromatography coupled to mass spectrometry. The limit of detection (3.50 mg kg−1), limit of quantitation (11.7 mg kg−1) and recoveries (99–103%) were adequate for sample analysis. The measurement uncertainty was estimated by the propagation of errors and experimental standard uncertainties (precision, accuracy, and analytical curves) and type B uncertainties from traceable measurement instruments. The low relative uncertainty (10%) and the adequate reproducibility demonstrated method suitability. The CZE-DAD results were compared to the MW method through the respective expanded standard uncertainties and normalized error. This new method is promising to be used in seafood inspection and continuous laboratory evaluations using instrumentation not very expensive to acquire and maintain.
DC. (Myrtaceae), popularly known as "cereja-do-Rio-Grande", is a native tree from Brazil, popularly used as a hypoglycemiant. Crude hydroalcoholic extract (CHE) and fractions (insoluble (FI), ...dichloromethane (FDM), ethyl acetate (FEA) and butanol (FBu)) of leaves were assessed to determine the phenolic chemical composition by HPLC-ESI-MS/MS. 10 compounds were identified, being 7 new for this species: rutin, isoquercitrin, luteolin-7-
-rutinoside, mandelic acid, naringenin, luteolin-7-
-glucoside and salicylic acid. Extract and fractions showed inhibitory activity on acetylcholinesterase (AchE) enzyme (best result: IC
= 44.19 µg mL
, for FEA) and α-glucosidase (α-Glu) (best result: IC
= 31.25 ± 0.15 µg mL
, for CHE). The observed antioxidant and inhibitory activity on the AchE and α-Glu is due to, at least in part, the presence of phenolic compounds in the samples.
In this study, the viability of applying cork and montmorillonite clay modified with ionic liquid as biosorbents in the rotating‐disk sorptive extraction technique was investigated. Specifically, ...this was aimed at the determination of methyl paraben, ethyl paraben, propyl paraben, and isobutyl paraben, with separation/determination by high‐performance liquid chromatography coupled with mass spectrometry. The optimization of the method for both biosorbents was performed using multivariate procedures. The extraction efficiencies for the target compounds in aqueous matrices were compared to those obtained using the commercial sorbent Octadecil Silano‐C18. The optimum extraction conditions for both natural sorbents were the use of an ammonia solution (pH 10) as desorption solvent and an extraction time of 30 min. The proposed methods show limits of quantification of 0.8 μg/L for cork, 3.0 μg/L for montmorillonite clay and 6.0 μg/L for Octadecil Silano‐C18. The relative recoveries from river water and tap water samples ranged from 80.3 to 118.7% and 80.0 to 119.9% for cork and montmorillonite clay modified with ionic liquid, respectively. Relative standard deviations were obtained for intra‐ and interday precisions of <15% and <19% for cork and <19% and <17% for montmorillonite clay modified with ionic liquid.
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Although rare, amoebic keratitis (AK) is a disease caused by Acanthamoeba spp. that can lead to blindness. The drugs currently available for its treatment are very toxic, which has ...motivated the investigation for more effective and safe therapeutic options. In this study, the in vitro activity of ß-caryophyllene (BCP) was exploited taking into account its action against other protozoans as well as its well-known healing and anti-inflammatory properties (aspects relevant for the AK pathogenesis). On the other hand, high volatilization and oxidation phenomena are found for this compound, which led to its incorporation into nanoemulsions (NEs). Two emulsifying agents were tested, resulting in monodisperse systems with reduced droplet size (<265 nm) and high surface charge (positive and negative for NEs prepared with cetrimonium bromide −CTAB and Phosal® 50+, respectively). NEs prepared with CTAB were shown to be more stable after long-term storage at 4 and 25 °C than those prepared with Phosal®. Pure BCP, at the highest concentration (500 µM), resulted in a level of inhibition of Acanthamoeba trophozoites equivalent to that of reference drug (chlorhexidine). This activity was even greater after oil nanoencapsulation. The reduced droplet size could improve the interaction of the oil with the microorganism, justifying this finding. Changes in surface charge did not impact the activity. Positively charged NEs improved the interaction and retention of BCP in the cornea and thus should be prioritized for further studies.
The juçara palm tree produces a small spherical and black-purple fruit similar to açaí. It is rich in phenolic compounds, especially anthocyanins. A clinical trial evaluated the absorption and ...excretion of the main bioactive compounds in urine and the antioxidant capacity in serum and erythrocytes of 10 healthy subjects after juçara juice intake. Blood samples were collected before (0.0 h) and 0.5 h, 1 h, 2 h, and 4 h after a single dose (400 mL) of juçara juice, while urine was collected at baseline and 0-3 and 3-6 h after juice intake. Seven phenolic acids and conjugated phenolic acids were identified in urine deriving from the degradation of anthocyanins: protocatechuic acid, vanillic acid, vanillic acid glucuronide, hippuric acid, hydroxybenzoic acid, hydroxyphenylacetic acid, and ferulic acid derivative. In addition, kaempferol glucuronide was also found in urine as a metabolite of the parent compound in juçara juice. Juçara juice caused a decrease in the total oxidant status of serum after 0.5 h in comparison to baseline values (
< 0.05) and increased the phenolic acid metabolites excretion. This study shows the relationship between the production of metabolites of juçara juice and the total antioxidant status in human serum, indicating evidence of its antioxidant capacity.
Although parabens have several features of ideal preservatives, different studies have shown that they may affect human health due to their estrogenic activity. Therefore, various strategies have ...been applied to reduce their skin penetration. However, the effect of paraben combinations on transdermal permeation has not yet been investigated. Thus, the objective of this study was to evaluate paraben permeation in pig ear skin using a Franz diffusion cell system with capillary electrophoresis detection, in order to identify which paraben combinations (defined by a factorial design) have the lowest skin permeation. The permeation of isolated parabens was also evaluated and the permeation characteristics, obtained by the Moser model, confirmed that lipophilicity and molecular weight may influence the systemic absorption of these compounds. In previous tests using isolated parabens, methyl and ethyl parabens presented greater retention in the epidermis compared to the dermis, while propyl and butyl parabens had similar retention profiles in these layers. An increase in ethanol concentration and experimental time promoted greater parabens retention in the dermis compared to the epidermis. The binary combinations of methyl and ethyl parabens as well as of methyl and propyl parabens (added to several cosmetic products in order to increase the antimicrobial spectrum) reduced significantly their permeation rates through pig ear skin (with the exception of EP), probably due to the high retention of these parabens in the epidermis and dermis.
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