Adsorptive stripping voltammetric determination of venlafaxine in urine with a mercury film microelectrode

An adsorptive stripping voltammetric procedure for the determination of the antidepressant venlafaxine in urine using a mercury film microelectrode wasdeveloped. The method is based on controlled adsorptive accumulation of the drug at the potential of 1.00V (vs. Ag/AgCl) in the presence of 1.25 x10 -2 molL- 1 borate buffer (pH 8.7). Urine samples were analyzed directly after performing a ten-fold dilution with the supporting electrolyte but without other pretreatment. The limit of detection obtained for a 30 s collection time was 0.693x 10- 6 mol L -1. Recovery experimentsgave good results at the 10 -6 mol L- 1 level (bias less 5% were obtained)

Pyrethroid pesticide metabolite, 3-PBA, in soils: method development and application to real agricultural soils

3-Phenoxybenzoic acid (3-PBA) is a shared metabolite of several synthetic pyrethroid pesticides (SPs) resulting from environmental degradation of parent compounds and thus occurs frequently as a residue in samples. Hence, the importance of 3-PBA evaluation after pyrethroid application. There is a gap of analytical methods to determine 3-PBA in soil samples. Therefore, an analytical method that combines the solid-phase extraction (SPE) and gas chromatography-mass spectrometry (GC/MS) detection has been developed for the determination of 3-PBA in soil samples. The analytical method was validated in terms of linearity, sensitivity, intra- and inter-day batch precisions, recoveries, and quantification limits. An SPE method using a Strata X cartridge allows obtaining limits of detection and quantification equal to 4.0 and 13.3 ng g-1, respectively. Under optimized conditions, the method average recovery levels ranged from 70.3 to 93.5% with a relative standard deviation below 3.4%. Method intra- and inter-day precision was under 5.0 and 4.8%, respectively. The developed method was applied to 11 agricultural soil samples in the north of Portugal. The developed methodology allowed for the determination of the pyrethroid metabolite, 3-PBA, in agricultural soil samples at levels of few ng g-1. Graphical abstract ᅟ.I. Bragança is financially supported by FCT through the doctoral research grant financed by fellowship (SFRH/BD/52504/2014). This work was supported by the Associate Laboratory for Green Chemistry-LAQV which is financed by national funds from FCT/MCTES (UID/QUI/50006/2013) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007265).info:eu-repo/semantics/publishedVersio

Determination of pesticides in fruit and fruit juices by chromatographic methods. An overview

In order to combat a variety of pests, pesticides are widely used in fruits. Several extraction procedures (liquid extraction, single drop microextraction, microwave-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, solid-phase extraction, solid-phase microextraction, matrix solid-phase dispersion, and stir bar sorptive extraction) have been reported to determine pesticide residues in fruits and fruit juices. The significant change in recent years is the introduction of the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) methods in these matrices analysis. A combination of techniques reported the use of new extraction methods and chromatography to provide better quantitative recoveries at low levels. The use of mass spectrometric detectors in combination with liquid and gas chromatography has played a vital role to solve many problems related to food safety. The main attention in this review is on the achievements that have been possible because of the progress in extraction methods and the latest advances and novelties in mass spectrometry, and how these progresses have influenced the best control of food, allowing for an increase in the food safety and quality standards

Assessment of Pyrethroid Pesticides in Topsoils in Northern Portugal

Pyrethroid insecticides are emerging contam-inants broadly used for insect pest control in agriculture,veterinary, and domestic applications. Limited informa-tion can be found in literature regarding pyrethroidpesticide soil contamination in playgrounds and agricul-tural areas. The focus of this study was on new findingsrelated to the spatial and seasonal occurrence of pyre-throid pesticide contamination in soils of northern Por-tugal. The soils were tested during summer and winterseasons. Pyrethroid pesticides were not found in the tenplaygrounds sampled during both seasons. For the 18agricultural soil samples tested, deltamethrin was theonly pyrethroid detected, just during the summer sea-son. For those, three of the samples taken were found tobe positive with concentrations between 15.7 and101.7 ng g−1. The results denote the need for monitoringand assessment of pyrethroid pesticide contamination inPortuguese soil. Further research is needed to access the ecological potential impact of pyrethroid pesticides onsoil.This work was supported by the Associ-ate Laboratory for Green Chemistry - LAQV which is financed bythe national funds from FCT/MCTES (UID/QUI/50006/2013) andco-financed by the ERDF under the PT2020 Partnership Agree-ment (POCI-01-0145-FEDER - 007265).info:eu-repo/semantics/publishedVersio

Assessment of a Formulation Containing a Castanea sativa Shells Extract on Skin Face Parameters: In Vivo Evaluation

In the last years, the demand for new eco-friendly ingredients has increased on the cosmetic market. Consumers are more aware of sustainable principles and, simultaneously, more conscious regarding the skin aging process. Chestnut (Castanea sativa) shells are a food by-product produced in high quantities in Europe. This waste has been described as a rich source of phenolic compounds with skin biological effects, such as antioxidant, antiradical, and anti-inflammatory activities. Despite the huge number of assays reporting the richness of chestnut shell extracts in bioactive compounds as well as the development of cosmetic formulations containing these extracts, no in vivo assays have assessed their clinical efficacy in human volunteers. The aim of this study was to evaluate the effect on skin face parameters of a formulation containing a chestnut shell extract in human volunteers (n = 22) who applied the product twice per day, for 56 days. For that, biophysical techniques, including Corneometer®, Cutometer®, and PrimosPremium, were employed, allowing the quantification of skin hydration and firmness, as well as of wrinkles’ depth and volume and wrinkles’ skin roughness. The results demonstrated that the formulation led to a slight decrease in roughness and wrinkles’ depth, although no significant differences with respect to a placebo were observed. In addition, a clear improvement of skin hydration was achieved (t0 = 54.00 Arbitrary Units (A.U.) and t56 = 58.62 A.U.). In contrast to the placebo, the active formulation increased skin firmness up to 31.76% in 50.00% of the volunteers, but without significant differences with respect to the placebo, probably due to the short period of treatment. A long-term use of the product is recommended to possibly observe significant differences in all parameters.This research was funded by the project PTDC/ASP-AGR/29277/2017—Castanea sativa shells as a new source of active ingredients for Functional Food and Cosmetic applications: a sustainable approach, supported by national funds by FCT/MCTES and co-supported by the Fundo Europeu de Desenvolvimento Regional (FEDER) throughout COMPETE 2020—Programa Operacional Competitividade e Internacionalização (POCI-01-0145-FEDER-029277). It was also funded by the projects UIDB/50006/2020 and UIDP/50006/2020 through national funds. This work was also financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences—UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB. The authors are thankful to Sortegel for the chestnut samples and their availability during this work. The authors are thankful to Evonik for the samples. Ana Margarida Silva is thankful for the Ph.D. grant (SFRH/BD/144994/2019) financed by POPH-QREN and subsidized by the European Science Foundation and Ministério da Ciência, Tecnologia e Ensino Superior. Francisca Rodrigues (CEECIND/01886/2020) is thankful for her contract financed by FCT/MCTES—CEEC Individual Program Contractinfo:eu-repo/semantics/publishedVersio

Study on the changes of soil chemical characteristics as result of prescribed fire

Every year, particularly during the summer period, the Portuguese forests are devastated by forest fire that destroys their ecosystems. So in order to prevent these forest fires, public and private authorities frequently use methods for the reduction of combustible mass as the prescribed fire and the mechanical vegetation pruning. All of these methods of prevention of forest fires alter the vegetation layer and/or soil [1-2]. This work aimed the study of the variation of some chemical characteristics of soil that suffered prescribed fire. The studied an area was located in the Serra of Cabreira (Figure 1) with 54.6 ha. Twenty sampling points were randomly selected and samples were collected with a shovel before, just after the prescribed fire, and 125 and 196 days after that event. The parameters that were studied were: pH, soil moisture, organic matter and iron, magnesium and potassium total concentration. All the analysis followed International Standard Methodologies. This work allowed to conclude that: a) after the prescribed fire; i) the pH remained practically equal to the the initial value; ii) occurred a slight increase of the average of the organic matter contents and iron total contents; b) at the end of the sampling period compared to the initial values; i) the pH didn´t change significantly; ii) the average of the contents of organic matter decreased; and iii) the average of the total contents of Fe, Mg and K increased

Electrochemical methods in pesticides control

The state of the art of voltammetric and amperometric methods used in the study and determination of pesticides in crops, food, phytopharmaceutical products, and environmental samples is reviewed. The main structural groups of pesticides, i.e., triazines, organophosphates, organochlorides, nitrocompounds, carbamates, thiocarbamates, sulfonylureas, and bipyridinium compounds are considered with some degradation products. The advantages, drawbacks, and trends in the development of voltammetric and amperometric methods for study and determination of pesticides in these samples are discussed

HPLC- MS Flavonoid determination and antioxidant capacity of Brazilian dehydrated bee pollen

Bee-pollen, produced by Apis mellifera bees, is an important source of proteins, lipids, vitamins and minerals for the hive, being considered one of nature's most completely nourishing foods. Its composition may vary according to the geographical region and its quality is influenced by harvest method and processing conditions. Although it has good nutritional components, beepollen contains significant amounts of polyphenols with recognized health benefits, including antioxidant activity. The present study aimed to evaluate the flavonoid composition, using HPLC-MS technique; and the antioxidant activity, using two different methods (DPPH and ORAC), of eight dehydrated bee-pollen samples collected in different Brazilian apiaries. The sample with the highest antioxidant capacity using DPPH method was produced in Rio Grande do Sul State (110.85 mol TE/g) while the sample with the least antioxidant capacity was collected in Bahia State (9.97 mol TE/g). The same sample from Rio Grande do Sul State presented the highest antioxidant capacity using ORAC method (542.00 mol TE/g), while the lowest value was observed in a sample from Mato Grosso State (133.70 mol TE/g). The flavonoid analysis using HPLC-MS revealed the following variations: catechin (0.69 to 0.75 mg/100 g); naringenine (4.57 to 18.36 mg/100 g); rutin (3.36 to 46.80 mg/100 g); quercetin (1.86 to 67.91 mg/100 g) and kaempferol (5.50 to 44.97 mg/100 g). In the sample with the highest antioxidant capacity (Rio Grande do Sul State) was observed 40 peaks in the HPLC-MS, while the samples with the lowest antioxidant capacities the number of peaks were 25 (Mato Grosso State) and 22 (Bahia State); therefore, the variety of compounds may have influenced the antioxidant capacity of the samples.info:eu-repo/semantics/publishedVersio

Occupational exposure of firefighters to polycyclic aromatic hydrocarbons in non-fire work environments

This work aims to characterize personal exposure of firefighters to polycyclic aromatic hydrocarbons (PAHs) in non-fire work environments (fire stations), and assesses the respective risks. Eighteen PAHs (16 considered by USEPA as priority pollutants, dibenzo[a,l] pyrene and benzo[j] fluoranthene) were monitored in breathing zones of workers at five Portuguese fire stations during a normal shift. The obtained levels of PAHs fulfilled all existent occupational exposure limits as well as air quality guidelines with total concentrations (Sigma PAHs) in range of 46.8-155 ng m(-3). Light compounds (2-3 rings) were the most predominant congeners (74-96% of Sigma PAHs) whereas PAHs with 5-6 rings accounted 3-9% of Sigma PAHs. Fuel and biomass combustions, vehicular traffic emissions, and use of lubricant oils were identified as the main sources of PAHs exposure at the studied fire corporations. Incremental lifetime cancer risks were below the recommend USEPA guideline of 10(-6) and thus negligible for all the studied subjects, but WHO health-based guideline level of 10(-5) was exceeded (9-44 times) at all fire corporations. These results thus show that even during non-fire situations firefighters are exposed to PAHs at levels that may promote some adverse health outcomes; therefore the respective occupational exposures to these compounds should be carefully controlled. (C) 2017This work was supported by European Union (FEDER funds through COMPETE) and National Funds (Fundação para a Ciência e Tecnologia) through projects UID/QUI/50006/2013, POCI/01/0145/FEDER/007265 and UID/EQU/00511/2013-LEPABE, by the FCT/MECwith national funds and co-funded by FEDER in the scope of the P2020 Partnership Agreement. Additional financial support was provided by Fundação para Ciência e Tecnologia through fellowships SFRH/BD/80113/2011 and SFRH/BPD/105100/2014. The authors are thankful to all firefighters involved in the study and to collaborators from Escola Superior de Saúde from Instituto Politécnico de Bragança.info:eu-repo/semantics/publishedVersio