Desenvolvimento e aplicação de método GC-MS/MS para análise simultânea de 17 HPAs em material particulado atmosférico

Os hidrocarbonetos policíclicos aromáticos (HPAs) estão associados ao aumento da incidência de diversos tipos de cânceres no homem. Essas moléculas são formadas principalmente na queima incompleta de matéria orgânica, sendo encontradas em todos os compartimentos ambientais. Órgãos regulamentadores das áreas ambiental e de saúde ocupacional consideram 17 HPAs como contaminantes atmosféricos prioritários. Este trabalho apresenta um método para análise simultânea destes HPAs utilizando-se a cromatografia a gás acoplada à espectrometria de massas operando no modo tandem (GC-MS/MS). Os limites de detecção e quantificação do método mostraram-se até 5 vezes inferiores aos obtidos no método GC-MS (SCAN). O método mostrou-se seletivo para análise de HPAs em extratos de amostras de material particulado atmosférico. Uma análise comparativa de dois sistemas de solventes (diclorometano/metanol 4:1 v/v e hexano/acetona 1:1 v/v) para a extração de HPAs, utilizando amostras de material particulado atmosférico, revelou que ambas as misturas de solventes possuem poder de extração semelhante. Os resultados sugerem que é possível realizar extração de HPAs de material particulado atmosférico em ultra-som com a mistura hexano/acetona (1:1), que é menos tóxica em relação à mistura diclorometano/metanol (4:1), bastante utilizada nestas análises, sem perdas significativas na exatidão do método.

Comparison of Potassium and Sodium Content in Diet and Non-Diet Soft Drinks by Using Capillary Electrophoresis with Capacitively Coupled Contactless Conductivity Detection

Capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C4D) was used for determination of sodium and potassium concentrations in diet and non-diet soft drinks. Higher sodium concentrations were found in the diet samples due to the utilization of sodium salts of cyclamate and saccharine as sweeteners. The CE-C4D method can be used by food industries and health regulatory agencies for monitoring sodium and potassium content, not only in soft drink but in many others food products.

Validação de método analítico para análise de amitraz em mel utilizando GC/TSD

Este artigo descreve a validação de método analítico para determinação do acaricida amitraz em mel utilizando extração com n-hexano/acetona, cleanup em cartucho de extração em fase sólida (SPE) e análise por cromatografia a gás com detector termoiônico seletivo (GC-TSD). O método pode ser utilizado para monitorar a presença do pesticida amitraz em mel, devido aos bons parâmetros analíticos, precisão (CV<11%) e exatidão (>80%) dentro do intervalo 100-400 ng g-1. O limite estabelecido na União Européia, pelo Committee for Veterinary Medicinal Products, para amitraz em mel (200 ng g-1) está dentro deste intervalo. A resposta do sistema analítico apresentou linearidade entre 100 e 800 ng mL-1 com coeficiente de correlação de 0,9996, limite de detecção (LD-7 ng g-1) e de quantificação (LQ-100 ng g-1). O método validado foi utilizado para avaliar a qualidade de méis comercializados na cidade de Araraquara/SP, nas quais não foram detectados resíduos de amitraz.

Soluble tissue sugar content and leaf blast severity in response to the application of calcinated serpentinite as a silicon source in irrigated rice

A field experiment conducted with the irrigated rice cultivar BRS Formoso, to assess the efficiency of calcinated serpentinite as a silicon source on grain yield was utilized to study its effect on leaf blast severity and tissue sugar levels. The treatments consisted of five rates of calcinated serpentinite (0, 2, 4, 6, 8 Mg.ha-1) incorporated into the soil prior to planting. The leaf blast severity was reduced at the rate of 2.96% per ton of calcinated serpentinite. The total tissue sugar content decreased significantly as the rates of serpentinite applied increased (R² = 0.83). The relationship between the tissue sugar content and leaf blast severity was linear and positive (R² = 0.81). The decrease in leaf blast severity with increased rates of calcinated serpentinite was also linear (R²= 0.96) and can be ascribed to reduced sugar level.

RELATIONSHIP BETWEEN LIGNIN CONTENT AND QUALITY OF Pinus taeda SEEDLINGS1

ABSTRACT The essay objective was to correlate lignin content resulting from tigmomorphogenesis induced by stem swaying with survival and post-planting growth of P. taeda seedlings. Seedlings were subjected to daily frequencies (0, 5, 10, 20 and 40 movements) of stem swaying for 60 days. By the end of the treatments, we determined lignin content of below and aboveground seedling tissues. Four replicates per treatment were planted in a area cultivated with pines. Ninety days after planting, survival and increments of seedling height, stem diameter and stem volume were quantified. Application of 20 stem swayings increased lignin in both below and aboveground plant tissues. Outplanted seedling survival was reduced with 40 stem swayings while growth increments were increased with both 10 and 20 stem swayings. Lignin content from belowground plant tissues was positively correlated with outplanted seedling survival while lignin from aboveground tissues correlated with height and stem volume increments. P. taeda seedlings with higher lignin content have higher survival chances after planting.

Development of capacitive sensor for measuring soil water content

The irrigation management based on the monitoring of the soil water content allows for the minimization of the amount of water applied, making its use more efficient. Taking into account these aspects, in this work, a sensor for measuring the soil water content was developed to allow real time automation of irrigation systems. This way, problems affecting crop yielding such as irregularities in the time to turn on or turn off the pump, and excess or deficit of water can be solved. To develop the sensors were used stainless steel rods, resin, and insulating varnish. The sensors measuring circuit was based on a microcontroller, which gives its output signal in the digital format. The sensors were calibrated using soil of the type “Quartzarenic Neosoil”. A third order polynomial model was fitted to the experimental data between the values of water content corresponding to the field capacity and the wilting point to correlate the soil water content obtained by the oven standard method with those measured by the electronic circuit, with a coefficient of determination of 93.17%, and an accuracy in the measures of ±0.010 kg kg-1. Based on the results, it was concluded that the sensor and its implemented measuring circuit can be used in the automation process of irrigation systems.

Jatropha seed oil content and yield under different irrigation and potassium fertilization levels

The aim of this research was to evaluate the effects of different irrigation depths and potassium dosages, of Jatropha seed oil content and yield. The experimental design used was randomized blocks, in split-plots, with four replicates. The treatments were four water depths (plots) and four potassium dosages (subplots) applied through irrigation water. The water depths were applied based on the percentage of accumulated evaporation of a Class A (ECA) tank and of rainfall, as following: L0 = without irrigation, L40, L80 and L120, representing 40, 80 and 120% of the balance, respectively. The potassium dosages were K30, K60, K90 and K120 (30, 60, 90 and 120kg ha-1 of potassium, respectively). The oil extraction of samples was done through chemical extraction by organic solvent. The seeds used in this test were from the sampling of two seed productions from 2009, second year of crop production. It was possible to observe that irrigation use increased oil yield and decreased the oil content of Jatropha seed. Potassium fertilization did not influence oil content and yield. There was a relative increase of efficiency in water use producing oil until certain water depth, and after that there was a decrease.

Soil penetration resistance in a rhodic eutrudox affected by machinery traffic and soil water content

Soil compaction caused by machinery traffic reduces crop yields. This study aimed to evaluate the effects of intensive traffic, and the soil water content, on the soil penetration resistance (PR) of a Rhodic Eutrudox (Distroferric Red Latosol, Brazilian Classification), managed under no-tillage (NT). The experiment consisted of six treatments: NT with recent chiseling, NT without additional compaction, and NT with additional compaction by 4, 8, 10 and 20 passes of a harvester with a weight of 100 kN (70 kN on the front axle). Undisturbed soil samples were collected at 5.5-10.5 cm and 13.5-18.5 cm depth to quantify the soil bulk density (BD). The PR was assessed in four periods, using an impact penetrometer, inserted in the soil to a depth of 46 cm. The effect of traffic intensities on the PR was small when this variable was assessed with the soil in the plastic consistency. Differences in PR among treatments increased as the soil water content decreased. The increase in the values of PR and BD was higher in the first passes, but the increase in the number of traffics resulted in deeper soil compaction. The machinery traffic effects on PR are better characterized in the friable soil consistency.

Construction and calibration of TDR probes for volumetric water content estimation in a Distroferric Red Latosol

The determination of volumetric water content of soils is an important factor in irrigation management. Among the indirect methods for estimating, the time-domain reflectometry (TDR) technique has received a significant attention. Like any other technique, it has advantages and disadvantages, but its greatest disadvantage is the need of calibration and high cost of acquisition. The main goal of this study was to establish a calibration model for the TDR equipment, Trase System Model 6050X1, to estimate the volumetric water content in a Distroferric Red Latosol. The calibration was carried out in a laboratory with disturbed soil samples under study, packed in PVC columns of a volume of 0.0078m³. The TDR probes were handcrafted with three rods and 0.20m long. They were vertically installed in soil columns, with a total of five probes per column and sixteen columns. The weightings were carried out in a digital scale, while daily readings of dielectric constant were obtained in TDR equipment. The linear model θν = 0.0103 Ka + 0.1900 to estimate the studied volumetric water content showed an excellent coefficient of determination (0.93), enabling the use of probes in indirect estimation of soil moisture.

Coverage mobilization in the sowing line and its influence on temperature and water content and on maize emergence

Straw on sowing line modifies seed germination environment regarding temperature and water content. Given these considerations, the aim of this study was to evaluate different mechanisms for coverage mobilization on the sowing line and their effect on germination environment of maize seeds, mainly in relation to the dynamics of straw in the seedbed, water content and soil temperature. Treatments consisted on the combination of two mechanisms at front of furrow opener, composed of cutting disc and row cleaners, with three mechanisms behind the seed furrower for returning the soil, consisting of three covering mechanisms, commercial and prototype models. It was found that straw presence on the surface of sowing line contributed to germination of maize seeds, maintenance of temperature and soil water content. The cutting disc treatment, associated with prototype, introduced percentages of water content near the ones in bottom layer, and this soil water content was 29.7% with 93.75% of straw coverage and deeper seeding depth, granting better conditions for seed germination. However, the straw coverage removal on soil by the row cleaners and its low sowing depth caused water loss in the lines resulting in great reduction of the emergence speed index in maize seedlings.

Composition of Hawthorn (Crataegus spp.) Fruits and Leaves and emblic Leafflower (Phyllanthus emblica) Fruits

Hawthorn (Crataegus sp.) is widely distributed in the northern hemisphere (Asia, Europe and North America). It has been used as a medicinal material and food for hundreds of years both in Europe and in China. Clinical investigations and other research suggest that extracts of hawthorn fruits and leaves have multiple health effects including hypolipidaemic, anti-atherosclerotic, hypotensive, cardioprotective and blood vessel relaxing activities. Hawthorn fruit extracts have also displayed antioxidant and radical scavenging activities. Emblic leafflower fruit (Phyllanthus emblica) is widely used in Chinese and Indian traditional medicine. It has been found to have anti-cancer, hypoglycaemic and hypolipidaemic activities as well as cardioprotective effects and antioxidant activity. The fruit is currently used as a functional food targeted at obese people in China. Phenolic compounds, procyanidins (PCs), flavonols and C-glycosyl flavones in hawthorn and hydrolysable tannins in emblic leafflower fruits are considered among the major bioactive compounds in these berries. Moreover, hawthorn and emblic leafflower fruits are rich in vitamin C, triterpenoids, fruit acids, sugar alcohols and some other components with beneficial effects on the health of human beings. The aim of the thesis work was to characterise the major phenolic compounds in hawthorn fruits and leaves and emblic leafflower fruits as well as other components contributing to the nutritional profile and sensory properties of hawthorn fruits. Differences in the content and compositional profile of the major phenolic compounds, sugars, acids and sugar alcohols within various origins and species of hawthorn were also investigated. Acids, sugars and sugar alcohols in the fruits of different origins/cultivars belonging to three species (C. pinnatifida, C. brettschneideri and C. scabrifolia) of hawthorn were analysed by gas chromatography (GC-FID) and mass spectrometry (Publication I). Citric acid, quinic acid, malic acid, fructose, glucose, sorbitol and myo-inositol were found in all the subspecies. Sucrose was present only in C. scabrifolia and three cultivars of C. pinnatifida var. major. Forty-two phenolic compounds were identified/tentatively identified in fruits of C. pinnatifida var. major by polyamide column chromatography combined with high-performance liquid chromatograph-electrospray ionisation mass spectrometry (HPLC-ESI-MS) (Publication II). Ideain, chlorogenic acid, procyanidin (PC) B2, (-)-epicatechin, hyperoside and isoquercitrin were the major phenolic components identified. In addition, 35 phenolic compounds were tentatively identified based on UV and mass spectra. Eleven major phenolic compounds (hyperoside, isoquercitrin, chlorogenic acid, ideain, (-)-epicatechin, two PC dimers, three PC trimers and a PC dimer-hexoside) were quantified in the fruits of 22 cultivars/origins of three species of Chinese hawthorn by HPLC-ESI-MS with single ion recording function (SIR) (Publication III). The fruits of the hawthorn cultivars/origins investigated fell into two groups, one rich in sugars and flavonols, the other rich in acids and procyanidins. Based on the compositional features, different biological activities and sensory properties may be expected between cultivars/origins of the two groups. The results suggest that the contents of phenolic compounds, acids, sugars and sugar alcohols may be used as chemotaxonomic information distinguishing the hawthorn species from each other. Phenolic compounds in fruits and leaves of C. grayana and their changes during fruit ripening/harvesting were investigated using HPLC-UV-ESI-MS (Publication IV). (-)-Epicatechin, PC B2 and C1, hyperoside and a quercetin-pentoside were the major phenolic compounds in both fruits and leaves. Three C-glycosyl flavones (a luteolin-C-hexoside, a methyl luteolin-C-hexoside and an apigenin-C-hexoside) were present in leaves in abundance, but only at trace levels in fruits. Ideain and 5-O-caffeoylquinic acid were found in fruits only. Additionally, eleven phenolic compounds were identified/tentatively identified in both leaves and fruits (three B-type PC trimers, two B-type PC tetramers, a quercetin-rhamnosylhexoside, a quercetin-pentoside, a methoxykaempferol-methylpentosylhexoside, a quercetin-hexoside acetate, a methoxykaempferol-pentoside, chlorogenic acid and an unknown hydroxycinnamic acid derivative). The total content of phenolic compounds reached the highest level by the end of August in fruits and by the end of September in leaves. The compositional profiles of phenolic compounds in fruits and leaves of C. grayana were different from those of C. pinnatifida, C. brettschneideri, C. scabrifolia, C. pinnatifida. var. major, C. monogyna, C. laevigata and C. pentagyna. Phenolic compounds in emblic leafflower fruits were characterised by Sephadex LH-20 column chromatography combined with HPLC-ESI-MS (Publication V). A mucic acid gallate, three isomers of mucic acid lactone gallate, a galloylglucose, gallic acid, a digalloylglucose, putranjivain A, a galloyl-HHDP-glucose, elaeocarpusin and chebulagic acid represented the major phenolic compounds in fruits of emblic leafflower. In conclusion, results of this study significantly increase the current knowledge on the key bioactive and nutritional components of hawthorn and emblic leafflower fruits. These results provide important information for research on the mechanism responsible for the health benefits of these fruits.

Mobile learning and video experience in delivering digital content

In recent years, the worldwide distribution of smartphone devices has been growing rapidly. Mobile technologies are evolving fast, a situation which provides new possibilities for mobile learning applications. Along with new delivery methods, this development enables new concepts for learning. This study focuses on the effectiveness and experience of a mobile learning video promoting the key features of a specific device. Through relevant learning theories, mobile technologies and empirical findings, the thesis presents the key elements for a mobile learning video that are essential for effective learning. This study also explores how previous experience with mobile services and knowledge of a mobile handset relate to final learning results. Moreover, this study discusses the optimal delivery mechanisms for a mobile video. The target group for the study consists of twenty employees of a Sanoma Company. The main findings show that the individual experience of learning and the actual learning results may differ and that the design for certain video elements, such as sound and the presentation of technical features, can have an impact on the experience and effectiveness of a mobile learning video. Moreover, a video delivery method based on cloud technologies and HTML5 is suggested to be used in parallel with standalone applications.

Europeana content priorities

David Smithin esitys Europeana työpajassa 20.11.2012 Helsingissä.