改性海藻酸纳米胶囊对氯氟氰菊酯的释放性能

以DCC/DMAP偶联反应将胆固醇基接枝到天然多糖海藻酸钠上,制备了胆固醇基接枝海藻酸钠衍生物(CSAD),采用乳化法对氯氟氰菊酯进行了负载,得到载药纳米胶囊。通过FTIR、1HNMR、荧光光谱、动态光散射、TEM和释药实验分别对改性海藻酸钠的结构和疏水性能以及载药纳米胶囊的形貌结构和释药性能进行了表征。结果表明,改性海藻酸钠的取代度为5.3%⁷.9%,其临界聚集质量浓度由1.23 mg/L降为0.267.9%,其临界聚集质量浓度由1.23 mg/L降为0.26⁰.63mg/L,且随着取代度的增大,疏水基的增多,临界聚集质量浓度降至更低。所制备的载药纳米胶囊的d50为(576.4±7.4)nm。Zeta电位值为(-32.3±0.6)mV,在水溶液中能够表现出极好的稳定性能。对比常规AEO n微乳剂,CSAD的氢键作用是CSAD纳米胶囊具备缓释性能的关键因素。     

氯氟氰菊酯的气相色谱分析

采用气相色谱法分析氯氟氰菊酯的含量,试样用三氯甲烷溶解,以磷酸三苯酯为内标物,使用5%SE-30/Chromsorb W-HP为填充物的玻璃柱和氢火焰离子化检测器,对试样中的氯氟氰菊酯进行气相色谱分析.方法的标准偏差为0.28%,变异系数为0.29%,平均回收率为100.37% ,线性相关系数为0.9999.     

氯氟氰菊酯的气相色谱分析

氯氟氰菊酯化学名称为α-氰基-3-苯氧苄基-3(2-氯-3,3,3-三氟-1-丙烯基)-2,2-甲基环丙烷羧酸酯。其分析方法国内尚未见报道。我们用上分103型气相层析仪,氢火焰离子化检测器,以测量峰高,外标定量,获得了准确度、精密度均较为满意的结果。     

氯氟氰菊酯乳油的气相色谱分析

氯氟氰菊酯分析有过报道,本文用气相色谱对其乳油进行定量分析。 实验部分 一、仪器与试剂 1.仪器:山东鲁南化工仪器厂生产的SP-501N气相色谱仪,氢火焰离子检测器,10微升微量注射器。 2.试剂与样品 丙酮、氯仿等溶剂均为分析纯 内标物:邻苯二甲酸二壬酯(色谱纯) 标准样品:英国卜内门化学有限公司进口     

氯氟氰菊酯的气液色谱分析

关于氯氟氰菊酯的分析测试,I.C.I公司采用毛细管色谱法和液相色谱法,我们对其气液色谱分析进行了研究,得到了较为满意的结果。 一、仪器与试剂 仪器:北分SP-3402气相色谱仪,具氢火焰离子化检测器。配 HP-3394A积分仪。 试剂:氯氟氰菊酯纯品(I.C.I)公司提供);邻苯二甲酸二壬酯(经色谱鉴定无干扰杂质);二氯甲烷(分析纯)。     

高效氯氟氰菊酯不同剂型对桃小食心虫的防效评价

为明确不同剂型的高效氯氟氰菊酯对苹果树桃小食心虫田间防效的差异,参照农药田间药效试验准则,开展田间防治试验.2年的试验结果表明:微乳剂、水乳剂、乳油3种剂型同期防效差异小于4%,差异不显著,微乳剂、水乳剂可作为乳油的替代剂型.可湿性粉剂药后5～10 d的防效与乳油差异不大,但药后15 d防效比乳油低7%～12%,并表现为差异显著.     

氯氟氰菊酯的毛细管气相色谱分析

氯氟氰菊酯的分析用毛细管气相色谱法，以30 M DB－210色谱柱对其定量分析，方法准确可靠，精密度高。     

毛细管色谱法测定2.5%氯氟氰菊酯乳油

毛细管色谱法测定２．５％氯氟氰菊酯乳油王维国，常华（甘肃省定西教育学院化学系，７４３０００）（甘肃省陇中农药厂）氯氟氰菊酯的填充柱分析已有报道［１］，我们应用毛细管色谱法对２．５％乳油进行了含量测定。实验部分一、仪器与试剂１．仪器１００２型气相色谱仪...     

2.5％高效氯氟氰菊酯纳米微乳剂的研发与应用

[目的]研究2.5%高效氯氟氰菊酯纳米微乳剂的配方及其实际应用情况。[方法]采用优化组合法对不同表面活性剂进行筛选试验,确定最优配方。[结果]经研制,得到优化配方:2.5%(折百)高效氯氟氰菊酯,15%乳化剂(6%磷酸酯型阴离子表面活性剂、9%苯乙烯基苯酚聚氧乙烯醚),余量为水。田间试验结果表明该产品对小白菜蚜虫的防效优于同等含量的常规微乳剂。[结论]制剂各项指标符合要求,且配方中无溶剂的加入,具有较高的经济效益和市场应用前景。     

氯氟氰菊酯的大口径毛细管柱气相色谱分析

本文建立了大口径毛细管柱气相色谱分离测定了２．５％氯氟氰菊酯乳油制剂的分析和中等极性的农残Ⅱ２５米×０．５３毫米大口径石英毛细管柱，用氮气作载气，以邻苯二甲酸二辛酯作内标，方法简便相关性好，变异纱数为０．１１７％和回收率为９９．２％－１００．６％。     

载药蒙脱石/海藻酸钠凝胶球的制备和释放性能

以离子交换方式将硫酸氢氯吡格雷插入蒙脱石层间,再用海藻酸钠包衣得到凝胶球。利用XRD、FTIR进行表征以及体外释放实验检测缓释效果。结果表明,硫酸氢氯吡格雷成功地插入蒙脱石层间,蒙脱石的层间距由1.25 nm增大到1.48 nm;体外释放实验显示在1 h内载药凝胶球的累积释放量为12.9%,表明载药蒙脱石/海藻酸钠凝胶球能明显的减少药物突释,因此可将它作为硫酸氢氯吡格雷的缓释载体。     

Preparation and investigation of sodium alginate nanocapsules by different microemulsification devices

Numerous techniques of preparation have been reported for the encapsulation of the core material, but the microemulsion technique is the most effective and commonly used for encapsulation. In this article, three microemulsification devices including ultrasonic stirrer, labo ratory reactor, and mechanical stirrer were used to produce the alginate nanocapsules containing peppermint oil. The effect of different parameters on surface morphology, mean particle size, and size distributions were investigated. The results indicated that the ultrasonic stirrer is the best device to make the nanocapsules containing essential oils prepared by microemulsion method, so that the size of nanocapsules prepared by ultrasonic stirrer was about 56 nm. Also, the results of GC‐MS, FTIR, and TGA show that quantities of the remaining compounds in nanocapsules prepared by ultrasonic stirrer are higher than other devices. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41904.     

Synthesis of styrene based liquid-filled polymeric nanocapsules by the use of RAFT-mediated polymerization in miniemulsion

Nanocapsules (below 100 nm) with liquid cores and molar mass controlled polystyrene shells were synthesized by an in situ miniemulsion polymerization reaction in the presence of a RAFT (reversible addition fragmentation chain transfer) agent. The formation of structured particles with the targeted core/shell morphology, i.e. liquid cores and polymeric shells, is extremely dependent on the type of RAFT agent used in conjunction with the type of initiator used. Different RAFT agents lead to different polymerization rates, thus resulting in different chain lengths as a function of time. This will influence viscosity and consequently chain mobility and can therefore cause a deviation from the desired morphology. The type of initiator used influences the surface activity of entering oligomers and is therefore also an important factor in obtaining the correct structure. Results showed that a RAFT agent that causes no rate retardation (phenyl 2-propyl phenyl dithioacetate, PPPDTA), used in conjunction with a surface active initiating species (potassium persulfate, KPS), is able to lock the locus of polymerization at the droplet/water interface. This results in entering oligomers being anchored at the droplet/water interface with consequent core/shell (nanocapsule) formation only if the RAFT agent used leads to a sufficiently rapid increase in chain length with time and thus a restriction of chain mobility of the mediated species.     

Swelling and drug release behavior of calcium alginate/poly (sodium acrylate) hydrogel beads

In the present work calcium alginate/poly (sodium acrylate) composite beads have been prepared by in situ formation of cross-linked poly (sodium acrylate) network, within the calcium alginate (CA) beads. The CA/poly (SA) beads have been found to be stable for more than 48 h, in the physiological fluid (PF) of pH 7.4, while the plain alginate beads disintegrated within a couple of hours. The water uptake of beads was investigated under various composition parameters such as the amount of alginate, concentration of ionic cross-linker Ca⁺⁺ ions, monomer sodium acrylate (SA) contents, and degree of cross-linking. The beads also exhibited fair stability in the media of varying pH. Finally the release of model drug methylene blue (MB) was investigated. It was found that plain CA and CA/poly (SA) composite beads exhibited different release mechanisms.     

Removal of colloidal particles utilizing gelation reaction of sodium alginate

A novel technique utilizing the gelation reaction of natural polymers has been proposed for the separation of solid from liquid in difficult-to-filter colloidal suspensions. This technique is especially effective in the treatment of colloidal muddy water of high solid concentration, which is often produced as a byproduct of certain construction processes. Colloidal suspensions are mixed with a sodium alginate solution, and this mixture is added to a calcium chloride solution, resulting in the entrapping of colloidal particles by the calcium alginate gel. Gel suspensions are then drained gravitationally, followed by mechanical expression of gel particles. Fundamental aspects of this process are investigated by using sodium bentonite as an experimental material. The alginate-bentonite mixture is added dropwise to the calcium solution. Decreasing the droplet size of the mixture expedites gelation since the diffusion of calcium ions into droplets determines the rate of gelation reactions. Reducing the alginate content expedites expression of the gel since alginate content is inversely proportional to the rate of expression.     

复凝聚法制备壳聚糖/海藻酸钠纳米香精胶囊

以壳聚糖和海藻酸钠为壁材,古龙香精为芯材,在高速乳化条件下,通过复凝聚方法制备了纳米香精胶囊。研究了助凝聚剂种类、交联剂种类以及交联固化温度对香精胶囊的形状、尺寸及分布的影响。应用TEM和激光粒度分析仪对香精胶囊的粒子尺寸、形态及分布进行了表征。结果表明,以TPP和CaCl2为助凝聚剂、以戊二醛为交联剂、在35℃条件下能制备出球型规整、粒径均匀、干态尺寸约为80nm、湿态尺寸约为160nm的纳米级香精胶囊。热重分析表明纳米香精胶囊的热分解起始温度大于200℃,具有良好的热稳定性。UV-Vis测试表明,纳米香精胶囊的装载量为34.3%,包埋率为87.2%。     

Production of bioethanol by immobilized Saccharomyces Cerevisiae onto modified sodium alginate gel

BACKGROUND: Microbial bioethanol production is an important option in view of the finite global oil reserves. Bioethanol fermentation was carried out using immobilized microorganisms (Saccharomyces cerevisiae, Zymomonas mobilis, Pichia stipitis, etc.), which has many advantages compared with the use of free cells. Various support materials have been used for bioethanol fermentation, and alginate gels have been one of the most widely used matrices for cell entrapment. The aim of this study was increased bioethanol production by Saccharomyces cerevisiae immobilized on alginate gels. First, N‐vinyl‐2‐pyrrolidone was grafted onto sodium alginate. Then, the properties of ethanol production were investigated using the matrix obtained. RESULTS: The performance of ethanol fermentation was affected by calcium chloride concentration, N‐vinyl‐2‐pyrrolidone grafted onto the sodium alginate, sugar concentration and the percentage of immobilized cell beads. These effects were optimized to give maximum ethanol production. Ethanol production was accelerated when sodium alginate polymer was modified with N‐vinyl‐2‐pyrrolidone. The maximum concentration, productivity and yield of ethanol were 69.68 g L^?1, 8.71 g L^?1 h^?1 and 0.697 g g^?1, respectively. CONCLUSION: The new polymeric matrix, when compared with sodium alginate, showed better ethanol production due to the hydrophilic property of N‐vinyl‐2‐pyrrolidone. The results suggest that the proposed method for immobilization of Saccharomyces cerevisiae has potential in industrial applications of the ethanol production process. Copyright © 2011 Society of Chemical Industry     

Controlled release of insecticide carbaryl from sodium alginate,sodium alginate/gelatin,and sodium alginate/sodium carboxymethyl cellulose blend beads crosslinked with glutaraldehyde

Interpenetrating network polymeric beads of sodium alginate (NaAlg) and its blend with gelatin (gels) or sodium carboxymethyl cellulose (NaCMC) have been prepared by crosslinking with a common crosslinking agent, glutaraldehyde (GA), for the release of insecticide carbaryl (Carb). The prepared beads were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Scanning electron microscopy confirmed the spherical nature and surface morphology of the particles. Bead characteristics, such as carbaryl entrapment efficiency, particle size, equilibrium swelling degree, and carbaryl release kinetics, were determined. The effects of the preparation conditions, such as Carb/NaAlg ratio, time of exposure to GA, blend ratio, and temperature of release medium on the carbaryl release, were investigated for 25 days at 25°C. It was observed that the carbaryl release decreased with increase in crosslinking of network, while it increased with increase in Carb/NaAlg ratio and temperature. The release of carbaryl also increased with increase in Gel or NaCMC content in the blend beads. The highest carbaryl release was found to be 100%, for the beads that were prepared with 1 : 1 NaAlg/Gel at 16 days. The diffusion coefficients have been calculated for the transport of insecticide through the polymeric beads, using initial time approximation method. These values were also consistent with the carbaryl release data. The carbaryl release from most of the bead formulations followed the Fickian trend. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1310–1319, 2006     

丙烯腈接枝改性海藻酸钙水凝胶中水杨酸的释放行为

将海藻酸钙水凝胶与丙烯腈单体进行不同程度的接枝共聚改性,再由FTIR加以分析,并测定包埋了水杨酸模拟药物的改性海藻酸钙水凝胶在不同介质中的药物释放量。实验表明,改性海藻酸钙水凝胶的药物释放量既与介质有关,也取决于接枝率的大小。