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小麦粉中甲醛的提取问题是一个比较复杂的多因素问题。采用正交实验法,选用L9(34)正交实验表,在提取试剂、提取温度、提取时间等多个因素和水平中优选小麦粉中甲醛振荡提取的最佳条件。实验中甲醛提取量采用Nash试剂柱前衍生高效液相色谱法测定。结果表明,提取温度是小麦粉中甲醛提取的最主要因素,最佳的提取条件为提取温度30℃、提取液为硫酸钠、提取时间为40min。 相似文献
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地锦草总黄酮最佳提取分离工艺的研究 总被引:2,自引:0,他引:2
采用四因素三水平的正交实验方法,对地锦草总黄酮的最佳提取工艺进行了探索.采用乙酸乙酯萃取、酸碱沉淀、铅盐沉淀3种方法,对其最佳分离工艺进行了探索.正交实验结果表明:温浸法中四因素对地锦草黄酮的影响顺序为乙醇浓度>样液比>提取温度>提取时间.通过实验得到了地锦草总黄酮的最佳提取工艺:以10倍体积的50%的乙醇水溶液在80℃浸提1 h.地锦草总黄酮的最佳分离方法为酸碱沉淀法.这些数据为中药地锦草的开发和应用提供了科学依据. 相似文献
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采用微波辅助提取方法,以提取剂浓度、pH值、液固比、微波提取时间、温度等为考察因素,并以提取物中总鞣质的提取率为评价指标,使用磷钼钨酸-干酪素分光光度法为定量测定方法,在单因素实验的基础上,通过正交实验优化翻白草中鞣质的提取工艺.实验结果表明,最佳提取条件为:使用70%甲醇作为提取剂、液固比40∶1、提取液pH为8.0、提取温度为40℃、提取时间为10 min.还对翻白草不同部位(根、茎、叶)的鞣质含量进行分析,发现根部中鞣质的含量最大,其次为茎和叶.此外,采用高效液相色谱法对翻白草中鞣质的种类进行定性分析. 相似文献
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野菊花中蒙花苷的提取及其含量的测定 总被引:1,自引:0,他引:1
以乙醇为溶剂,采用溶剂回流提取方法结合微波、超声波辅助提取野菊花中的蒙花苷,用HPLC法测定。采用正交试验法研究了野菊花中蒙花苷提取和HPLC实验条件,并比较了采用不同的微波和超声波辅助提取方式对蒙花苷提取结果的影响。结果表明,溶剂回流提取最佳条件为:提取温度80℃,回流时间2.0 h,溶剂用量40 mL。应用于安徽等产地野菊花中蒙花苷的提取分析,结果显示,广东和广西产地药材含量明显更高;在相同的实验条件下采用微波辅助提取可使蒙花苷达到较高的提取率,特别是采用微波辐射药材后再进行溶剂回流提取,提取时间可缩短一半。 相似文献
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A new process for the preparation of soybean protein concentrate (SPC) by directly extracting full-fat soy flour with a mixture of hexane and aqueous ethanol was established. Compared with conventional methods, it has some advantages, such as saving energy and reducing protein denaturation caused by heat action during solvent recovery, because this process saves one step of solvent recovery. The effects of aqueous ethanol concentration and the mixure ratio (hexane to ethanol) on the degree of protein denaturation and product quality were investigated, on the basis of which the orthogonal tests were performed. The optimum technical parameters were obtained by analyzing the results of the orthogonal tests with statistical methods. We found that SPC can be obtained by extracting full-fat soy flour under the following conditions: mixture ratio hexane: 90% ethanol, 9:1, v/v; extraction temperature, 45 degrees C; ratio of solid to solvents, (1:2 w/v); and 5 repeated extractions (15 min each time). The results of quality analysis showed that solubility of the product was improved significantly [nitrogen solubility index (NSI) 46.6%] compared with that for ethanol washing of protein concentrate (NSI 8.7%). 相似文献
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福美双是重要的二硫代氨基甲酸酯(DTC)杀菌剂,在小麦中使用限量以1 mg/kg二硫化碳(CS2)计。目前我国相关检测方法是针对二硫代氨基甲酸酯一类的化合物,二硫代氨基甲酸酯通过与酸反应生成CS2,采用光谱法或色谱法测定CS2,间接实现二硫代氨基甲酸酯测定。该方法无法特异性实现对福美双的检测,因此开展小麦粉中福美双检测方法的研究具有重要意义。研究建立了高效液相色谱-二极管阵列检测(HPLC-DAD)测定小麦粉及面粉改良剂中福美双的分析方法。小麦粉及面粉改良剂样品用乙腈溶剂提取后,经涡旋、振荡、冰水浴超声和静置后取上清液过滤,供高效液相色谱测定。采用ZORBAX plus-C18色谱柱(150 mm×4.6 mm, 5 μm)分离,以水-乙腈为流动相洗脱分析,在波长280 nm下检测。实验优化了提取溶剂及其体积、振荡超声条件、色谱柱、检测波长、流动相等条件。该方法采用保留时间和紫外光谱图定性,外标法定量。该方法在线性范围内(0.30~30.0 μg/mL)线性关系良好,相关系数(r2)为0.99999。对小麦粉及面粉改良剂进行1.5、3.0、15 mg/kg 3个水平的加标回收试验,福美双的回收率为89.6%~98.3%,相对标准偏差为1.6%~3.9%(n=6)。方法的检出限和定量限分别为0.5 mg/kg和1.5 mg/kg。该方法采用溶剂提取,操作简单,分析时间短,特异性好,具有精密度高、重复性好、检出限低等特点,适用于小麦粉及面粉改良剂中福美双快速、准确的定量检测。 相似文献
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对杨梅树叶中杨梅素的提取有影响的有机溶剂浓度、提取温度、料液比、提取时间进行正交优化。结果表明,最佳提取工艺条件是乙醇体积分数95%,提取温度95℃,提取时间1.5h,料液比1:15,在此工艺条件下杨梅素提取率达到0.088%。 相似文献
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In the present study, a new method using microwave-assisted solvent extraction (MASE) technique followed directly GC analysis was developed for the extraction of volatile organic acids (VOAs) in tobacco. The MASE conditions (heating time, volume of extracting solvent and extraction temperature) were optimized by means of an orthogonal array design (OAD) procedure. The results suggested that extractant, temperature and heating time were statistically the most significant factors. The extracts were directly analyzed with capillary GC operating in splitless-injection mode on an Agilent HP-FFAP capillary column. Under optimum operating conditions, MASE showed significantly better recoveries than those obtained by the conventional extraction method (ultrasonic and reflux extraction), ranging from 90.6% to 103.2%. In addition, a drastic reduction of the extraction time (20 min versus 4 h) and solvent consumption (20 mL versus 100 mL) was achieved with an outstanding reproducibility (CV ≤5%). 相似文献
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应用气相色谱法测定了小麦粉中4种有机磷和拟除虫菊类农药的残留量.样品中的残留农药用乙腈提取分离,所得提出液减压蒸发至近干,再用吹氮法蒸干.残渣用正己烷-乙酸乙酯(9+1)混合溶液2 mL溶解,所得溶液经中性氧化铝固相萃取柱净化.收集洗脱液,再用上述混合溶液10 mL淋洗固相萃取柱,收集洗脱液与上次洗脱液合并,减压蒸发至... 相似文献