超高效液相色谱法测定饲料中斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯含量方法的研究

为有效快速测定饲料中斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯含量,饲料经甲醇、正己烷和乙酸乙酯混合液萃取后,在氮气保护下浓缩,用甲基叔丁基醚-乙腈溶液复溶,注入超高效液相色谱仪中进行测定。结果表明:斑蝥黄浓度为1.25~10.0μg/mL,β-阿朴-8’-胡萝卜素酸乙酯为2.50~20.0μg/mL线性关系良好;斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯的检测限为0.06 mg/kg,定量限为0.20 mg/kg。斑蝥黄5个添加水平的平均回收率为72.8%~82.8%,相对标准偏差(RSD)为0.41%~1.06%;β-阿朴-8’-胡萝卜素酸乙酯5个添加水平的平均回收率为72.0%~82.8%,RSD为0.46%~1.41%。说明该方法简便、快速、灵敏度高、准确度好,适用于测定饲料中斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯含量。     

二十碳五烯酸甲酯标准样品的研制

以深海鱼油为基础原料,将其皂化水解为游离脂肪酸,经尿素—甲醇包合粗分离后,以硫酸—甲醇甲酯化,再经硝酸银—硅胶柱层析精分离,得到高纯度的二十碳五烯酸甲酯标准物质。经定值检测,确定其化合物纯度≥98%。     

分相萃取法纯化朝鲜蓟中洋蓟素的工艺研究

以朝鲜蓟提取物为原料、乙酸乙酯为萃取剂,考查萃取时间、分相时间、提取物质量浓度、相比、萃取温度、pH值等因素对萃取率的影响,并通过正交试验优化洋蓟素的最佳萃取参数。结果表明,朝鲜蓟中洋蓟素的最佳萃取参数为萃取时间30 min,分相时间80 min,提取物质量浓度10.0 g/L,相比1.25∶1,萃取温度35℃,pH值4.0,此时洋蓟素萃取率达到67.37%。     

苯并噻二唑甲酸三氟乙酯诱导仙客来抗枯萎病的研究

为了明确新型化合物苯并噻二唑甲酸三氟乙酯对土传病害的诱导抗病作用,本文研究了该化合物诱导仙客来对枯萎病的抗病效果。通过叶面喷施苯并噻二唑甲酸三氟乙酯可诱导仙客来对枯萎病的抗病效果,在仙客来移栽缓苗后7d叶面喷施该化合物,不同浓度对枯萎病的抗病效果不同,其中100mg.L-1的处理,在诱导后25、30和35d的抗病效果分别为82.90%、58.59%和64.17%;在仙客来成株枯萎病发病初期用该化合物诱导,抗病效果仍可达63.91%,显著高于噁霉灵处理（47.63%）。该研究将为寻求通过叶面喷雾施药防治园艺作物土传病害的新途径起到参考作用。     

农业航空喷雾雾滴漂移及其数学分析

通过田间试验研究,探索了装配GP—81喷头的运五型飞机喷洒2,4—D丁酯乳油稀释液的雾滴漂移状况,建立了有关数学模型。研究表明,较低蒸发度的水雾滴漂移距离为340m,较高挥发度的2,4—D丁酯漂移距离达700m;雾滴密度和沉降量随下风距离增加而减小较快,雾滴直径减小较慢;气象因子和喷液配方对雾滴漂移有重要影响;三次多项式方程Y=b_0 b_1X b_2X~2 b_3X~3能很好地描述雾滴漂移与下风距离的关系,模型中的参数具有明确的实际意义,提出了喷洒2,4—D丁酯时的有效隔离带宽度。     

萜烯二硫代羧酸乙酯的合成及其选矿性能

以松节油为起始原料合成了萜烯二硫代羧酸乙酯和萜烯黄原酸乙酯的混合物,并对其在选矿工艺中用作铜捕收剂的性能进了探索性研究     

Safflower petals: A source of gamma linolenic acid

Safflower petals have been shown to have a lot of medicinal and therapeutic values. Indian safflower petal samples were analyzed for the red pigment carthamin, protein and oil contents. The petal oil (4.0–5.8%) was further analyzed for its fatty acids followed by alpha linolenic acid (15–19%) and palmitic acids (14–16%). Gamma linolenic acid, which has a lot of therapeutic value was present to an extent of 2–3%; decanoic and dodecanoic acids (2–5%) were also present.     

Influence of surface charge on viscosity behavior of cellulose microcrystal suspension

Microcrystalline cellulose with minimal surface charge was prepared from softwood kraft pulp via hydrolysis by 4N hydrochloric acid instead of sulfuric acid. To this material, sulfate ester groups as surface charge were introduced by treating with 55% (w/w) sulfuric acid. A treatment at 60°C for 2h gave nearly the same level of surface charge as that of the H₂SO₄ -hydrolyzed microcrystal. The number of sulfate groups were controlled by changing the H₂SO₄ treatment conditions. Although the microscopic size and shape of the microcrystalline particles were the same irrespective of the preparation method, the introduction of surface charge drastically reduced the viscosity and removed its time dependence. These changes in viscosity behavior are considered to result from charge-induced dispersion of loose aggregates existing in the initial charge-free microcrystals prepared by HCl hydrolysis.Part of this report was presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998     

玉米幼苗对芘污染土壤微生物活性及多样性的影响

通过盆栽土培试验研究了玉米幼苗生长期间对芘污染土壤微生物活性及多样性的影响。结果表明,玉米加快了土壤中芘的降解,提高了芘在土壤中的降解速率。试验期间,根际土中可提取态芘含量显著低于非根际土,根际土微生物生物量碳、微生物熵、多酚氧化酶和脱氢酶活性均高于非根际土,代谢熵低于非根际土。脂肪酸（FAME）分析结果表明,与非根际土相比,芘污染玉米根际土微生物群落结构发生了显著的变化,主要表现在真菌特征脂肪酸以及真菌/细菌的比值显著升高,细菌和GN^-细菌特征脂肪酸显著降低,且这种效应随着培养时间的推移在P〈0.01水平显著。根际土和非根际土中丛枝菌根真菌、GN^＋细菌和放线菌特征脂肪酸差异随着培养时间的延长逐渐加大,45 d时其差异均在P〈0.05水平显著。