Mathematical modelling for extraction of oil from Dracocephalum kotschyi seeds in supercritical carbon dioxide

Extraction of oil from Dracocephalum kotschyi Boiss seeds using supercritical carbon dioxide was designed using central composite design to evaluate the effect of various operating parameters including pressure, temperature, particle size and extraction time on the oil yield. Maximum extraction yield predicted from response surface method was 71.53% under the process conditions with pressure of 220 bar, temperature of 35 °C, particle diameter of 0.61 mm and extraction time of 130 min. Furthermore, broken and intact cells model was utilised to consider mass transfer kinetics of extracted natural materials. The results revealed that the model had a good agreement with the experimental data. The oil samples obtained via supercritical and solvent extraction methods were analysed by gas chromatography. The most abundant acid was linolenic acid. The results analysis showed that there was no significant difference between the fatty acid contents of the oils obtained by the supercritical and solvent extraction techniques.     

Formulation and evaluation of quince seeds mucilage – sodium alginate microspheres for sustained delivery of cefixime and its toxicological studies

Quince seed mucilage was used in a combination of sodium alginate to develop sustained-release microspheres of cefixime. Physical characterizations such as FTIR, TGA, DSC, and SEM were performed on the prepared microspheres. The swelling of microspheres was maximum at pH 7.4 and reduced at acidic pH. The average particle size ranged from 679 µm ± 0.21 to 810 µm ± 0.31, while the drug encapsulation efficiency range was found as 73.76 ± 0.24–85.63 ± 0.46. In vitro release profile of QSM-alginate-cefixime microspheres followed Korsmeyer-Peppas model (R² = 0.9732-–0.9946); and release was non-Fickian as we found value of n > 1. This study reveals the benefits of QSM-alginate microspheres for the sustained release of cefixime without any toxicity and it also improved antibacterial properties.     

萃取火焰原子吸收法测定高梁种皮中的硒

本文研究了微量元素硒，用APDC和MIBK萃取，火焰原子吸收法进行测定。通过萃取富集，既克服了硒的原子化效率低而难以测定的缺点，又消除了稳定剂Cu^2 及样品中所含有的其他金属离子对硒测定的干扰，用于高梁种皮中硒的测定，效果良好，方法简单，快速、准确，具有较高的准确度和精密度，相对标准偏差为4.18%，回收率为97.8%。     

种子光与抽运光能量比对布里渊放大的影响

利用瞬态包含抽运抽空的受激布里渊散射理论模型对布里渊放大器进行了数值模拟,给出了布里渊放大器中能量提取效率、种子光放大率、种子光脉宽压缩率和抽运光脉宽压缩率随Stokes种子光与抽运光能量比的变化规律,并用实验进行了验证,理论与实验符合得较好 关键词： 布里渊放大器 提取效率 种子光与抽运光能量比     

浙江龙塘山自然保护区种子植物区系的研究

本文为龙塘山自然保护区种子植物区系的初步研究结果 ,扼要报道了本区系现知的 1356种 (不包括种下等级 113亚种或变种、变型 ) ,分隶 144科 687属;对科、属的性质及分布区类型作了分析 ,表明本区系以温带性成分为主 ,也兼有相当的热带性成分 ,具有亚 热带特性;介绍了本区系世界单种属 38属 ,在中国为单种属的有 39属 ,分布于该地区的中国特有属 19属;珍贵植物 36种及列入中国珍稀保护植物 20种.通过与邻近山地植物区系比较分析 ,表明本区植物区系与西天目山、黄山、庐山的关系最为密切 ,显示出该区具有典型的华东植物区系的特征 .     

用M-C方法计算低能V+注入花生种子的深度-浓度分布

实验表明,低能重离子注入植物种子后的深度-浓度分布曲线是一个非对称高斯分布,直接用LSS理论计算该分布,与实验结果差别甚大.本文根据植物种子的结构特点,对靶材料进行了处理,并对LSS理论进行了修正,用M-C方法计算了初始能量为200keV的V 注入花生种子的深度-浓度分布,得到了与实验结果符合较好的分布曲线.     

固相萃取-大体积进样-气相色谱法定量分析油茶籽油中的矿物油

建立了一种固相萃取( SPE)离线净化,气相色谱(配备大体积进样系统( LVI))定量分析油茶籽油中矿物油污染物( MOSH)的方法。 SPE柱采用AgNO3渍活化硅胶为填料,同时比较了添加活化氧化铝前后的效果,确定SPE柱填料为10 g银渍活化硅胶-10 g活化氧化铝;LVI的程序升温( PTV)参数优化为初始温度75℃保持1 min(分流比200：1),以250℃/min 升温至370℃(关闭分流阀1 min);切换分流比为50：1;进样量40μL。结果表明：MOSH标准液体石蜡在5~500 mg/L范围呈良好线性关系,相关系数为0.998,方法的检出限和定量限分别为0.26 mg/kg 和0.80 mg/kg,加标回收率93.3％~112.7％,相对标准偏差( RSD)为1.8％~5.2％,日间和日内重复性(RSD)均小于2.6％。本方法用于市售11个油茶籽油中MOSH含量测定,其结果为6.8~76.7 mg/L。本方法操作简便、检出限低、重现性好且成本低廉,适用于食用油中MOSH的定量分析。     

Evaluation of chemical constitute,fatty acids and antioxidant activity of the fruit and seed of sea buckthorn (Hippophae rhamnoides L.) grown wild in Iran

In this investigation, the chemical compositions of berries from sea buckthorn were studied. The amount of ascorbic acid and β-carotene determined by HPLC was 170 mg/100 g FW and 0.20 mg/g FW, respectively. Total phenols, anthocyanins, acidity and total soluble solids (TSS) contents were 247 mg GAE/100 g FW, 3 mg/L (cyanidin-3-glucoside), 5.32% and 13.8%, respectively. Fruit antioxidant activity determined by the ferric reducing ability of plasma (FRAP) method was 24.85 mM Fe/100 g FW. Results confirmed the presence of six dominant fatty acids (determined by GC) in fruit including linoleic (34.2%), palmitoleic (21.37%), palmitic (17.2%), oleic (12.8%), linolenic (5.37%) and stearic acid (1.67%). Five dominant fatty acids of the seeds were linoleic (42.36%), linolenic (21.27%), oleic (21.34%), palmitic (6.54%) and stearic acid (2.54%). The nitrogen content was 3.96%. The P, K, Ca, Mg, Fe, Zn, Mn, Cu, Cd and Cl contents of fruit were 491, 1674, 1290, 990, 291, 29.77, 108.37, 17.87, 0.021 and 2.18 mg/kg DW, respectively.     

Adsorptive Removal of Hg(II) from Synthetic and Real Aqueous Solutions Using Modified Papaya Seed

The performance of chemically modified papaya seed (CMPS) adsorbent with carboxyl and amino groups has been studied. Adsorption experiments were performed with respect to the changes in initial pH of the solution, contact time, initial Hg(II) concentration, and CMPS dosage. Kinetic data were fitted to the pseudo-second-order model. The maximum adsorption capacity calculated by Langmuir model was 18.34 mg/g. CMPS was characterized by elemental analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy. The results indicate that adsorption mechanism of CMPS involves ion exchange (2Na⁺/Hg²⁺) and carboxylic-group-dominated surface complexation. Regeneration study revealed that CMPS can be used successfully for four cycles with a small adsorption capacity loss (6.8%).     

Ultrasonic-assisted binding of canistel (Lucuma nervosa A.DC) seed starch with quercetin

In order to provide a reference for improving the physicochemical properties of starch, the study of starch polyphenol complex interaction has aroused considerable interest. As a common method of starch modification, ultrasound can make starch granules have voids and cracks, and make starch and polyphenols combine more closely. In this research, canistel seed starch was modified by ultrasonic treatment alone or combined with quercetin. The molecular structure, particle characteristics and properties of starch were evaluated. With the increase of ultrasonic temperature, the particle size of the dextrinized starch granules increased, but the addition of quercetin could protect the destruction of starch granule size by ultrasonic; X-ray diffraction and infrared spectra indicated that quercetin was bound to the surface of canistel seed starch through hydrogen bonding, and the complex and the original starch had the same crystal structure and increased crystallinity; by molecular simulation, quercetin bound inside the starch molecular helix preserved the crystalline helical configuration of starch to some extent and inhibited the complete unhelicalization of starch molecules. Meanwhile, hydrogen bonding was the main driving force for the binding of starch molecules to quercetin, and van der Waals interactions also promoted the binding of both. In the physicochemical properties, as the temperature increased after the combination of ultrasonic modified starch combined with quercetin, the solubility, swelling force and apparent viscosity of the compound increased significantly, and it has higher stability and shear resistance.