高效液相色谱一步法快速测定10种有机酸

目的 建立一种同时检测10种有机酸的高效液相色谱检测方法.方法 采用Agilent ZORBAX SB-Aq液相色谱柱(250 mm×4.6 mm,5μm),优化分析条件:流动相KH2PO4溶液浓度、甲醇含量和柱温,同时检测草酸、酒石酸、丙酮酸、苹果酸、乳酸、乙酸、柠檬酸、丁二酸、富马酸和戊二酸的含量.结果 流动相为4...     

Determination of residual organic matter in extracted oil sands using a low temperature ashing method

The application of a low temperature ashing method for estimating total residual organic matter (toluene insolubles) in oil sands is described. A linear correlation exists between organic carbon content and loss on ignition at 400 ± 10 °C of solvent extracted oil sands. The ratio between total organic carbon and the weight loss on ignition (CT/LOl) owing to the removal of residual organic matter is much lower than that obtained for toluene soluble bitumen fractions, indicating very different chemical composition for the residual organic matter. The measured carbon content of the residual organic matter in oil sands suggests that this material could be a mixture of various fractions contained in resins, asphaltenes, asphaltic acids and humic acids.     

Pyrolysis studies of organic oxygenates: 3. High temperature rearrangement of aryl alkyl ethers

Thermal chemistry pathways of aryl alkyl ethers have been investigated under coal conversion-like conditions. Anisole is a thermally reactive compound having an oxygen functionality found in such coal precursors as lignins. Pyrolysis of anisoles was carried out using small batch autoclaves. Under thermolysis conditions anisole yielded a product distribution strongly dependent upon experimental parameters. Phenol, methane, CO and benzaldehyde are the low molecular weight products and polyphenyls and polyethers are the predominant high molecular weight products. The generation of CO is explained by a high temperature rearrangement of the phenyl group from O- to C- followed by rapid thermal decarbonylation of the benzaldehyde. Carbon monoxide formation from aryl alkyl ethers can thus be an important mechanistic pathway in coal conversion processes. By investigating the rearrangement using para-fluoroanisole it was shown that this rearrangement proceeds via a three-centered intermediate to para-fluorobenzaldehyde. No meta isomer was observed.     

甜菜机械化栽培技术经济效果的分析

机械化栽培甜菜平均单产33.18吨/公顷,比人工栽培生产田提高52.03%;平均含糖15.5度,比人工栽培生产田提高1.09度;平均技术效果138.2元/公顷;经济效果1588.8元/公顷;创造社会经济效益24.47万元。     

甜菜应用硫酸锌效果初报

锌是甜菜生长发育必需的微量元素之一。黑龙江省青冈县耕层土壤有效锌含量平均为0.48ppm,低于碳酸盐黑土有效锌含量0.6—1.53ppm的水平,是造成甜菜根产量和含糖率低的原因之一。给甜菜施用硫酸锌有助于增加株高、叶片数、根重和含糖率。根据作种肥、浸种及叶喷三种不同的用法,硫酸锌的用量分别以每亩1000g、40g和100g为宜。本文对硫酸锌不同的施用方法及不同用量的效果进行了讨论。     

Cultivation,preparation and consumption of ensete (ensete ventricosum) in Ethiopia

In Ethiopia almost 10 million people are dependent on ensete (Ensete ventricosum (Welw) Cheesrnan), also known as ‘false banana’. In the Gurage area in Central Ethiopia, agronomic and nutritional aspects of ensete were studied in 60 households in six villages. Ensete is propagated vegetatively and has a 6-year growing cycle during which it is transplanted three or four times. Men harvest the plants; women scrape the pseudo stem in order to separate the starchy pulp from the fibre, and pulverise the corm. The pulp is fermented and stored for up to 5–7 years in earthen pits. The yield of ensete food (ko'cho) was found to be 34 kg per plant or 9.5 tons ha ^?1 per year. Compared with other foods grown in Ethiopia, the energy yield of ensete (6.1 MJ m ^?2 per year) was higher than that of all cereals, Irish potato, sweet potato and banana, but lower than that of cassava. The protein yield of ensete was higher (11 ± 4gm^?2 per year) than all of the crops mentioned above, except for banana and Irish potato. To make ensete bread, fermented pulp is squeezed to make it drier, chopped to shorten the fibres and a 2 cm layer is baked for 15 min. Unfermented freshly harvested corm is also eaten after boiling. All foods have a low protein content (4–22 gkg^?1). Bu'lla, white desiccated juice collected from the pulp, is more energy rich (8.5 MJ kg^?1) than ko'cho (6.5 MJkg^?1). A dietary survey, conducted in 39 households comprising 237 persons, showed that the average daily intake of 0.55 kg ensete provided 68% of total energy intake, 20% of protein, 28% of iron but no vitamin A. Energy intake from all food consumed was very low, being only 60% of requirements, while protein intake at 107% was ample. Since ensete can be stored for years, is readily available throughout the year and can withstand dry periods, its cultivation can significantly improve household food security in highland areas prone to drought and famine.     

Effect of hot-air drying on flavour compounds of bell peppers (Capsicum annuum)

The influence of hot-air drying on the composition of both volatile and non-volatile flavour compounds of different Dutch bell pepper cultivars was investigated. Contents of glucose, fructose, ascorbic, citric, and oxalic acid decreased significantly after drying, while the levels of sucrose, malic, fumaric, and cis-aconitic acid increased. Glucose, fructose and ascorbic acid probably participate in Maillard reactions during heating. Different effects of drying could be distinguished on the composition of volatile compounds. The majority of these compounds evaporated during drying. Some compounds were partly retained in the dried bell peppers, whereas others disappeared completely. Gas chromatography-sniffing port analysis revealed that compounds with mainly “fresh” odour notes like lettuce/grassy/green bell pepper ((Z-2-3-hexenal), fruity/almond ((E)-2-hexenal), fruity (octanal), lettuce/green bell pepper ((Z)-3-hexenol), and grassy/green bell pepper ((Z)-2-hexenal) decreased or disappeared after drying. Another group of compounds increased or were formed during drying, like 4-octen-3-one, (E)-2-heptenal, (E)-2-octenal, (E,Z)- and (E,E)-2,4-heptadienal, decanal, and (E)-2-nonenal; most are known as autoxidation products of unsatu-rated fatty acids. The increased levels of 2-methylpropionic and 2- and 3-methylbutyric acid, 2-metlhylpropanal, and 2- and 3-methylbutanal seemed to be due to Strecker degradation. Gas chromatography-sniffing port analysis showed that the latter three compounds had distinct cacao, sweaty, and spicy odour characteristics.     

减少次氯酸盐漂白产生有害物质的研究

对蔗渣硫酸盐浆次氯酸盐漂白时如何减少有机结合氯和三氯甲烷的含量进行了研究，结果表明：在次氯酸盐漂白时加入Ｈ２Ｏ２并加入催化剂和用光照，能有效地减少废液中ＣＨＣｌ３的含量，纸浆和废液中有机结合氯的含量亦有所减少。通过Ｈ２Ｏ２ＣＨＣｌ３反应产物的气相色谱和电子自旋共振分析，以及氯苯酚类化合物与Ｈ２Ｏ２反应所发生的光致降解实验的结果，阐明了在次氯酸盐漂白时加入Ｈ２Ｏ２能减少ＣＨＣｌ３和有机结合氯含量的机     

液相色谱法测定天然酿造酱油和水解植物蛋白调味液中有机酸的研究

建立了高效液相色谱法测定天然酿造酱油和水解植物蛋白调味液中有机酸的方法,样品前处理简单,甲酸、苹果酸、琥珀酸、乳酸、酒石酸、乙酸、柠檬酸、丙酮酸、乙酰丙酸在弱阳离子交换柱上分离良好,其在一定线性范围内相关系数在0．9990以上,回收率在96．0—103．9％,检出限在0．001—0．005mg／mL,相对标准偏差在1．1—3．3％,并对天然酿造酱油和水解植物蛋白调味液样品进行了检测。     

水性纳米有机颜料的制备及其分散稳定性能的研究

在有机颜料分散过程中添加吸附促进剂,促进高分子分散剂在有机颜料表面吸附,成功制备了水性纳米有机颜料分散体系; 研究了水性纳米有机颜料分散体系的稳定性能.结果表明:在有机颜料分散过程中添加吸附促进剂,可制得分散稳定性能良好的水性纳米有机颜料.水性纳米有机颜料分散体系随着离心时间的延长,吸光度变化较小,仅有极少部分颗粒发生沉降.加热温度在50℃以下,粘度、粒径、Zeta电位基本没有变化;高于50℃后,颜料的性能明显变化,且温度越高变化越明显.将水性纳米有机颜料分散体系稀释32倍,其比吸光度仍高达97.56%,说明纳米颜料分散体系中发生沉降的粒子很少.所制得的水性纳米有机颜料分散体系具有较好的离心稳定性、耐热稳定性和稀释稳定性.