The production of biopolymers has been shown to be one of the most viable alternatives for the reduction of the use of conventional plastics. The oat hulls are a by-product with great ability to be incorporated into the production of biopolymers since it is a lignocellulosic compound. The lignin present in its composition can improve the strength of the material, however, it can also hamper its degradation. The aim of this study was to evaluate the degradation levels of composites produced from starch and polylactic acid with absence (T1) and presence of oat hulls (T2) through the Sturm test. In T2 it was a more uniform and smooth biopolymer. In addition, the use of oat hulls favored CO2 production, 8% more than T1. Although the loss of dry mass in T1 was 3% higher, it was possible to observe degradation in T2.
The objective was identifying three different anthocyanidins and to quantify them in six different berries. Results from the conventional method (using extraction with hydrochloric acid) were compared with data from the proposed method (without acid extraction). The following figures of merit were used: linearity, accuracy, linear range, limits of detection and quantification, using an ultra performance liquid chromatography (UPLC) coupled to a triple quadrupole mass spectrometer equipped with an electrospray ionization source. The separation of anthocyanidins can be achieved in a much smaller period of time (1.30 min) and the cyanidin from Morus nigra L., Rubus idaeus L. and Vaccinium myrtillus L. was found in higher amounts in extracts obtained from the proposed method. Proposed mechanisms of mass spectrometry (MS/MS) collisional induced dissociation for pelargonidin, cyanidin and delphinidin were obtained and this is the first time that concentrations of anthocyanidins present in fruits of Solanum americanum Mill. were reported.
ABSTRACT. The use of pesticides in agriculture is one of the current problems that may result in contamination of both ground and surface water and groundwater. Considering the environmental importance and the increasing use of herbicides in Maringá region, in the present work methods for extraction and determination of glyphosate (GLYP) and aminomethylphosphonic acid (AMPA) using solid phase extraction (SPE) and high performance liquid chromatography (HPLC) were developed. For SPE, anion exchange resin was used and elution was done with hydrochloric acid 50.0 mmol L -1 , achieving recovery rates of 82.5-116.2% and 67.1-104.0% for AMPA and GLYP, respectively. For HPLC determination the analytes were derivatized and injected in the HPLC with a C18 column and using mobile phase consisting of phosphate buffer 0.20 mol L -1 at pH 3.0 and acetonitrile (85:15); the monitoring was done at 240 nm. The analysis was performed in 8 min with the same limit of detection and limit of quantification for AMPA and GLYP of 0.09 and 0.20 mg L -1 , respectively. The methods were applied to analysis of public water supply samples and concentrations from 2.1 up to 2.9 μg L -1 for AMPA and from 2.3 up to 3.3 μg L -1 for glyphosate were found.Keywords: glyphosate, aminomethylphosphonic acid, SPE, HPLC, water quality.Determinação de glifosato e ácido aminometilfosfônico para verificar a qualidade da água de abastecimento público utilizando EFS e CLAE RESUMO. O uso de pesticidas na agricultura é um dos problemas atuais que podem resultar em contaminação do solo e de águas superficiais e subterrâneas. Levando em consideração a importância ambiental e o crescente uso de herbicidas na região de Maringá, foram desenvolvidos métodos de extração e determinação de glifosato (GLYP) e seu metabólito ácido aminometilfosfônico (AMPA) utilizando extração em fase sólida (EFS) e determinação por cromatografia líquida de alta eficiência (CLAE). Para EFS utilizou-se a resina trocadora aniônica e como eluente ácido clorídrico 50,0 mmol L -1 , atingindo-se taxas de recuperação na faixa de 82,5-116,2% e 67,1-104,0% para o AMPA e glifosato, respectivamente. Para determinação por CLAE, os analitos sofreram derivatização sendo injetados em cromatógrafo contendo coluna C18 e fase móvel constituída de solução tampão fosfato 0,20 mol L Palavras-chave: glifosato, ácido aminometilfosfônico, EFS, CLAE, qualidade da água.
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