Rapid quantification of residual glyphosate in water treated with layered double hydroxides using liquid chromatography / Quantificação rápida de glifosato residual em água tratada com hidróxidos duplos lamelares usando cromatografia líquida

High performance liquid chromatography and an optimized colorimetric method were applied to determine the residual glyphosate in waters treated with double lamellar hydroxides such as MgxAlyCO3.nH2O. The chromatographic determination was by means of derivatization with 9-fluorenylmethylchloroformiate and running time less than 2 minutes, faster than analogous methods in the literature. The colorimetric method was performed by optimizing the Ruhemann purple method. The chromatographic and colorimetric methods presented LOQ of 1.05 and 2.08 ?g / mL and LOD of 0.31 and 0.84 ?g / mL, respectively. The percentages of recovery of the methods are between 93 to 105% with RSD less than 2.35% for the chromatographic method and 6% for the colorimetric. Both methods depend on the temperature. The double hydroxide Mg1Al1CO3.nH2O has the highest percentage of charge density (5.54 nm2) and the best performance in removing glyphosate from the aqueous medium

Characterization of a brazilian smectite by solid state NMR and X-ray diffraction techniques

X-ray diffraction (XRD), differential thermal analysis (DTA) and 27Al and 29Si solid state MAS-NMR techniques were used to monitor the fractionation steps of a brazilian smectite, previously crushed, from Campina Grande, Paraíba. The sand, silt and clay fractions were obtained by physical and chemical treatments. The XRD analysis of sand and silt fractions showed that both fractions had predominant quartz and feldspar, respectively. The XRD results of the K+ saturated and heated clay fraction confirmed that the natural clay belongs to the 2:1 clay-mineral group, whereas the analysis of the Mg2+ saturated and glycolated clay fraction confirmed the presence of a smectite group clay. The MAS-NMR results of 27Al and 29Si showed that the sand fraction contains 79% of quartz and the silt fraction contains 55% of quartz, while the clay fraction is rich in smectite with low isomorphic replacement of Si by Al, and contains 38 % of quartz

Processo para aumentar a porcentagem de geraniol e nerol no óleo essencial de Melissa officinalis

Em 08/08/2014: Anuidade de pedido de patente de invenção no prazo extraordinário.DepositadaA presente invenção provê processo para aumentar a proporção de geraniol e nerol no óleo essencial de Melissa officinalis. As plantas cultivadas in vitro, em meio MS (Murashige e Skoog, 1962) acrescidos de diferentes combinações de citocininas e auxinas, apresentaram aumento significativo nas concentrações de nerol e geraniol no óleo essencial, quando comparadas com as plantas não tratadas com reguladores de crescimento

Caracterização Mineralógica de uma Bentonita da Mina Bravo, Boa Vista, Paraíba

A bentonite sample from Bravo mine, Boa Vista District (Paraíba, NE Brazil), presenting the high Cation Exchange Capacity (CEC) of 106meq/100g, was thoroughly characterized, in order to find the best added- value application for it. Smectite, quartz, and jarosite have been identified in the run of mine (ROM) sample, whereas the size fraction under 10μm contains only smectite with traces of quartz. All the iron in the sample is Fe3+, as analysed by 57Fe Mössbauer Spectroscopy, and its sole carriers are smectite, exclusively in the octahedral layer, and goethite, around 30% (wt) in both samples. According to solid state 27Al Nuclear Magnetic Ressonance, only 1% of the aluminium is located in the tetrahedral layer of the smectite, whereas 99% of it is octahedral. The clay’s chemical composition and its spectroscopic signature classify the chocolate bentonite as an iron-rich montmorillonite. Thermal analysis, with an endothermic peak due to smectite dehydroxylation at 488.6°C, and FTIR (Fourier Transformed Infrared) Spectroscopy, confirm the classification.A bentonita chocolate, oriunda da mina Bravo, Boa Vista, PB, foi detalhadamente caracterizada como subsídio a uma aplicação de maior valor agregado, considerando sua elevada capacidade de troca catiônica (CTC) – 106meq/100g. Foram identificados esmectita, quartzo e jarosita na amostra bruta, e a fração fina, abaixo de 10μm, contém apenas esmectita, com traços de quartzo. A espectroscopia Mössbauer do 57Fe indicou que todo o ferro da amostra é trivalente, carreado por goethita (de 28 a 32% do total) ou na camada octaédrica da esmectita. Ressonância Magnética Nuclear de 27Al no estado sólido (RMN-MAS de 27Al) indicou que apenas 1% do Al da amostra situa-se na camada tetraédrica da esmectita, estando o restante na camada octaédrica. A composição química da amostra, associada às considerações espectroscópicas, classificou a esmectita como uma montmorillonita rica em ferro. As análises termodiferenciais/ termogravimétricas, com o pico endotérmico de desidroxilação do argilomineral centrado em 488,6°C, e as análises de espectroscopia na região do infravermelho confirmam a classificação

PENGARUH MEKANISME GOOD CORPORATE GOVERNANCE DAN CORPORATE SOCIAL RESPONSIBILITY TERHADAP KINERJA KEUANGAN DENGAN MANAJEMEN LABA SEBAGAI VARIABEL MEDIASI (Studi Empiris pada Perusahaan Manufaktur yang terdaftar di Bursa Efek Indonesia tahun 2014)

Penelitian ini bertujuan untuk mengetahui pengaruh langsung antara mekanisme Good Corporate Governance (GCG) dan Corporate Social Responsibility (CSR) terhadap kinerja keuangan maupun melalui manajemen laba sebagai variabel mediasi. Data yang digunakan dalam penelitian ini merupakan data sekunder yang melibatkan 102 perusahaan manufaktur yang terdaftar di Bursa Efek Indonesia (BEI) untuk periode 2014. Data yang digunakan dalam penelitian ini dianalisis menggunakan Partial Least Square (PLS) dan dilakukan dengan bantuan software WarpPLS 5.0. Hasil penelitian menunjukkan mekanisme GCG berpengaruh positif terhadap kinerja keuangan begitu juga dengan CSR terhadap kinerja keuangan. Mekanisme GCG berpengaruh negatif terhadap manajemen laba sedangkan CSR berpengaruh positif terhadap manajemen laba. Manajemen laba berpengaruh negatif terhadap kinerja keuangan. Manajemen laba juga terbukti mampu memediasi pengaruh mekanisme GCG terhadap kinerja keuangan dengan bentuk mediasi sebagian sedangkan dalam memediasi pengaruh CSR terhadap kinerja keuangan, manajemen laba terbukti dapat menjadi mediasi penuh