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Ethyl Levulinate Obtained from Lignocellulosic Waste Material with Previous Delignification by Ultrasonic-Assisted Technique

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Journal of Agricultural Chemistry and Environment 2017年第1期6卷 93-103页

作者： Jorge Ernesto Solá-Pérez Hugo Saldarriaga-Norena mario murillo-tovar Centro de Investigaciones Químicas ICCBAUniversidad Autónoma del Estado de MorelosCuernavacaMéxico

Ultrasound-assisted pretreatment under mild operating conditions has been investigated for intensification of delignification to facilitate the obtaining of ethyl levulinate from biomass. The effect of pH (2 - 12), temperature (30°C - 70°C) and pretreatment time (0 - 120 minutes) has been studied for different biomass samples. The most favorable conditions were basic pH, temperature of 70°C and pretreatment time of 2 h, obtaining values of delignification near 80 percent. The ethyl levulinate is obtained in microwave directly via from samples before and after delignification and analyzed for GC-MS. The results evidenced better yields for the delignified samples.

关键词： Ethyl Levulinate Delignification Wheat Straw Sugarcane Bagasse Maguey Bagasse

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Optimization of Analytical Conditions to Determine Steroids and Pharmaceuticals Drugs in Water Samples Using Solid Phase-Extraction and HPLC

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American Journal of Analytical Chemistry 2011年第8期2卷 863-870页

作者： Ramiro Vallejo-Rodriguez Alberto Lopez-Lopez Hugo Saldarriaga-Norena mario murillo-tovar Leonel Hernandez-Mena Centro de Investigacion y Asistencia en Tecnologia y Diseno del Estado de Jalisco(CIATEJ) Normalistas 800Colinas de la NormalGuadalajaraMexico Facultad de Ciencias Quimicas Universidad Autonoma de CoahuilaRepublica Ote.SaltilloMexico

Two reliable methods were optimized to determine two steroids (17?-Estradiol and 17?-Ethinylestradiol) and two pharmaceutical drugs (ibuprofen and naproxen) using Solid-Phase Extraction (SPE) for sample preparation and High Performance Liquid Chromatography (HPLC) for analysis. SPE (C18) conditions were evaluated varying elution solvent volume, pH conditions and sample mass in the cartridge and reduction techniques of the extract. The efficiency of the analytical methods was evaluated by spiking ultrapure water samples with compounds at three and four levels of concentration for steroids and pharmaceutical drugs, re- spectively. The recoveries were independent (P > 0.05) of added mass of target analytes with a repeatability lower than 6.5% for steroids and 12.1% for pharmaceutical compounds. The recovery factor (coefficient of variation, CV) was higher than 83% for steroids (CV 93% for pharmaceuticals (CV < 5.2%). The optimized analytical method was applied for the evaluation of a steroid degradation test using ozone, finding that the estimated limit of detection is sufficient to determine the residual mass (μg?L–1) of 17β-Estradiol after the experiment.

关键词： Steroids Pharmaceuticals Drugs Solid-Phase Extraction HPLC-DAD

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Chemical Characterization of N-Hexane Extract Obtained from Lignocellulose Residual Contained in Agroindustrial Wastes

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Journal of Agricultural Chemistry and Environment 2018年第2期7卷 94-104页

作者： Jorge Ernesto Solá-Pérez Hugo Saldarriaga-Norena mario murillo-tovar Gustavo Ronderos-Lara Verónica Gisela López-Martínez Centro de Investigaciones Químicas ICCBAUniversidad Autónoma del Estado de MorelosCuernavacaMéxico

The chemical composition of n-hexane extractives from lignocellulose residual contained in different agroindustrial wastes was studied. The n-hexane extract, which accounted for 1.6% of total lignocellulose residual weight, was analysed by 1H-NMR and gas chromatography/mass spectrometry. The most predominant compounds identified were aliphatic hydrocarbons (lineal alkanes, branched alkanes, alkenes). Additionally, terpenes, ketones, fatty alcohols, fatty acids and steroids were also found together in minor amounts. The lipophilic compounds in n-hexane extracts in three lignocellulosic wastes, which is highly valuable information for a more complete industrial utilization of these lignocellulosic materials.

关键词： Wheat Straw Maguey Bagasse Sugarcane Bagasse N-Hexane Extract

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