激光粒度分析技术在药物研究和质量控制中的应用进展

近年来,激光粒度分析技术广泛应用于药物的质量研究和质量控制领域.从激光散射测定粒度的原理、仪器的一般要求和影响测试结果的因素、方法验证的要求以及该技术在药物领域中最新应用等方面进行综述,为激光粒度分析技术在药物中的应用开发提供有益的参考.     

超细稀土氧化物粉体粒度测定

采用美国布鲁克海文仪器公司制造的90 Plus粒度仪测定超细稀土氧化物粉体粒度. 以氧化钇为研究对象, 研究了分散剂、悬浮介质、待测样品浓度、分散时间等因素对亚微米级氧化钇粉体粒度测量精度的影响. 由此确定了能准确测定亚微米级氧化钇粉体粒度的测量条件.     

90Plus激光粒度仪测试聚丁二烯胶乳粒径的方法及注意事项，

粒度测试在工业生产中的应用非常广泛,如涂料、水泥、聚合物胶乳、药品、金属粉末等,不同的应用领域对粉体特性的要求各不相同.华锦集团双兴公司有一套1 万t/a的聚丁二烯胶乳(PBL)生产装置和1 m3 PBL中试装置,在PBL技术开发方面做了大量研究工作,在研发过程中需要及时了解和掌握PBL粒径的大小及其分布.因此笔者介绍了90Plus激光粒度仪测试PBL粒径的方法与注意事项,以供同行参考.     

纳米激光粒度仪在生物药品团聚物测试中的应用

探讨了纳米激光粒度仪测定生物药品团聚物质量浓度的方法。以SALD–7500nano颗粒测试仪为例,介绍其在测量纳米级颗粒物粒度范围方面的应用。通过进一步分析颗粒浓度与光强度成正比的关系获得以质量浓度形式给出的粒度分布数据。通过牛血清蛋白(BSA)团聚物测量的实例,验证了颗粒物质量浓度的测试方法。该方法可用于生物制药领域对团聚物的监控测量以及评价药品药效、安全性能等。     

纳米ATO颗粒粒度分布的脉冲超声波测量研究

讨论了脉冲超声波测量纳米ATO颗粒粒度分布方法中的3个步骤,即超声波衰减谱测量、严格数学模型的选型以及颗粒粒度分布的反演计算.通过发射脉冲超声波并利用变声程方法测量25 ℃时2%(体积分数)的纳米ATO-H2O分散液的超声衰减谱;选取McClements理论模型叠加BLBL理论模型共同描述纳米ATO颗粒分散液中的超声衰减现象;采用最优正则优化反演算法反演得到纳米ATO颗粒的粒度分布以及平均粒径.脉冲超声法检测结果显示,纳米ATO颗粒的平均粒径为25.6 nm,粒度分布为11.4 ～47.1 nm,CPS离心沉降纳米粒度分析仪测定结果分别为22.1 nm和10.1 ～62.6 nm.脉冲超声法检测结果与透射电镜图像以及离心沉降纳米粒度分析仪检测结果吻合较好,证明了脉冲超声波测量纳米颗粒粒度分布以及平均粒径的可行性与可靠性.     

染料黑白片XP1 400的粒度研究

本文测定了依尔福染料黑白片XP1 400在XPI套药中冲洗的染料影像及中间银影像的均方根粒度,同时又测定了在同样曝光条件下的涂层在普通黑白显影液中冲洗的黑白银影像的均方根粒度。结果表明,三种影像粒度随密度变化的规律完全不同。本文又用selwyn公式计算了中间银影像及黑白银影像的单位面积显出颗粒数,测试和计算结果表明,与黑白银影像比较,中间银影像具有均方根粒度明显低和单位面积显出颗粒数高的特点。这与光学显微镜下现察到的中间银影像及黑白银影像的形态是一致的。本文还根据实验及计算结果讨论了DIR成色剂在影像形成过程中的作用。     

我国发展为全球最大的粒度仪器市场

经过几十年的发展,中国不仅实现了粒度仪行业的"从无到有",更是发展为全球最大的粒度仪器市场,也是增长最快、竞争最激烈的市场。国产产品的技术进步飞速,部分国产产品的主要性能已经达到或接近国外同类产品的先进水平。目前,中国已经能够生产几乎所有类型的粒度测试仪     

南极乔治王岛菲尔德斯半岛的冻土结构特征研究

本文根据坑探、物探、测温、分层冻胀仪等资料分析,讨论了本区活动层的结构特征,论证了石环区碗状冻结面的存在,分析了活动层温度的分布规律以及粒度、粘土矿物、含盐量和电阻率等垂向剖面参数反映的高低不同地势间冻土结构的差异及其对冰缘地貌发育的控制作用,继而提出了本区冻土(包括下覆基岩)具有的4层结构,最后,推算了冻土上限及其垂直变化梯度。     

同时测量纳米颗粒悬浊液粒度、密度及浓度的方法研究

提出了一种基于超声检测同时测量纳米颗粒悬浊液的粒度、密度和浓度的方法.设计了一套高频宽带脉冲超声波检测系统,以纳米掺锑氧化锡(ATO)悬浊液为研究对象,结合脉冲回波技术,获得了频率为17 ～ 26 MHz的声衰减谱.据此运用最优正则化方法求解粒度反演方程,得到纳米ATO颗粒的分布曲线,中位径为22.07 nm,该值与离...     

照相影像RMS粒度的测试研究

RMS粒度是照相材料成像质量的重要特性。使用显微光密度计-电子计算机系统进行该项测定是目前最为先进的方法。这种方法自动进行数字采样,按编制好的程序计算,具有快速简便的优点。但测试过程中有许多重要环节,如果处理不当,计算出的结果值就完全不能代表样品的粒度水平而只是一个完全错误的结果。本文通过设计的各种实验,研究了仪器系统噪声,样品中宏观密度不均及影像数字化时采样间距对RMS粒度测值的影响。结果表明,必须选取恰当的实验参数和数据处理方法,才能消除上述各种干扰,得到RMS粒度的正确估值,同时,本文还对数字模拟光孔与真实光孔的RMS粒度测值作了比较,得到了有实际应用价值的结果。     

粒径可控的纳米铁酸铋的制备及其光催化性能

采用改进的聚丙烯酰胺凝胶法制备了BiFeO3纳米颗粒,利用热重-差热、红外光谱及X射线衍射等手段研究了干凝胶的热分解及BiFeO3的成相过程.结果表明,在600℃煅烧可制备出高纯的BiFeO3纳米颗粒.同时发现,随着双丙烯酰胺含量的增加,所得样品晶粒尺寸逐渐减小,从而制备出平均粒径约52～110nm的系列BiFeO3颗...     

Measurement of Continuous Particle Size Distributions of Finely Dispersed Powders by the Dynamic Light Scattering

Dispersity of finely dispersed powders with continuous bell-shaped particle size distributions is measured. The measurements are performed using two different dynamic light scattering instruments, a transmission electron microscope, and a sedimentograph equipped with an X-ray detector. Correlation functions measured with the dynamic light scattering instruments are processed using the CONTIN and KLUB software packages. Comparative analysis of the results obtained by different methods demonstrated that a reliable information on the dispersity of samples with wide particle size distributions can be obtained but using a combination of several analytical methods.     

Insights into information contained in multiplicative scatter correction parameters and the potential for estimating particle size from these parameters

This paper investigates the nature of information contained in scatter correction parameters. The study had two objectives. The first objective was to examine the nature and extent of information contained in scatter correction parameters. The second objective is to examine whether this information can be effectively extracted by proposing a method to obtain particularly the mean particle diameter from the scatter correction parameters. By using a combination of experimental data and simulated data generated using fundamental light propagation theory, a deeper and more fundamental insight of what information is removed by the multiplicative scatter correction (MSC) method is obtained. It was found that the MSC parameters are strongly influenced not only by particle size but also by particle concentration as well as refractive index of the medium. The possibility of extracting particle size information in addition to particle concentration was considered by proposing a two-step method which was tested using a 2-component and 4-component data set. This method can in principle, be used in conjunction with any scatter correction technique provided that the scatter correction parameters exhibit a systematic dependence with respect to particle size and concentration. It was found that the approach which uses the MSC parameters gave a better estimate of the particle diameter compared to using partial least squares (PLS) regression for the 2-component data. For the 4 component data it was found that PLS regression gave better results but further examination indicated this was due to chance correlations of the particle diameter with the two of the absorbing species in the mixture.     

粒度对石墨负极材料嵌锂性能的影响

研究了不同粒径（13～80 μm）石墨材料作为锂离子电池负极材料的嵌锂性能.结果表明，石墨粒度大小对嵌锂性能有明显影响，石墨的不可逆容量随着粒径的减小而逐渐增大，当粒径从80 μm减小到13 μm时，其不可逆容量增大了10％.而对可逆容量来说，随着粒径的减小，可逆容量逐渐增大;当粒径减小到20 μm时，可逆容量达到最大;再进一步减小石墨颗粒的粒径，可逆容量则随之减小.这表明石墨颗粒过大或过小都不利于锂离子的可逆脱嵌，只有合适的粒度才能最大限度地可逆脱嵌锂离子.根据不同粒度石墨的比表面的变化趋势，阐述了嵌锂性能随粒度变化的原因.     

Effect of Processing and Aging on Particle Size of Explosives

Influence of such processes as molding powder production, pel-lets pressing and aging under different condit/ons on particle size of TATB ( 1,3,S-trlamino-2,4,6-trinltrobenzene ) and HMX (cyclotetramethylenetetranitramine) was experimentally studied. The results showed that parflele size of these explosives was greatly changed before and airier moldinu powder produc-tion, but for different size grade of explosive this change was not the same; pressing process had also great effect on explosive particle size, but before and after ageing process explosive par-tide size did not change seriously.     

Particle Size Distribution Measurement and Assessment of Agglomeration of Commercial Nanosized Ceramic Particles

ABSTRACT

Commercially available powders with primary particle sizes of 10–100?nm (transition aluminas, Boehmites, and a commercially available silica dispersion) have been studied using three different instruments, a photocentrifuge (Horiba CAPA 700), photon correlation spectroscopy (PCS, Malvern Zetasizer 4), and an x-ray disc centrifuge (XDC, Brookhaven X-ray Disc Centrifuge BI-XDC). Particle size distributions for five powders were collected with each instrument and in conjunction with nitrogen adsorption measurements an agglomeration factor calculated. An example is given to show the importance of using a light scattering correction when measuring particle size distributions with a photocentrifuge for a gamma alumina powder where the uncorrected data can overestimate the D _V50 by up to a factor of 10 depending on the powder. The importance of the assessment of agglomeration and how different treatments such as milling modifies the agglomeration factor F _AG is illustrated for an “as received” and attrition milled gamma alumina. Results are discussed with respect to the assumptions and limitations of the different instruments. Results are presented after consideration of the hydrodynamic density in the sedimentation methods, and light scattering for the optical based methods. For narrow size distributions in the 15–25?nm range all three instruments show very a good correlation. When the size range approaches the 40–100?nm regime PCS is very sensitivity to small populations of agglomerates. The instrument giving the best resolution in the 10–100?nm range was found to be the XDC. The speed of measurement should also be born in mind and varies enormously from several minutes for the PCS to several hours for the sedimentation techniques. To assess the accuracy of the measured sizes a model spherical silica powder was analyzed on all the instruments as well as by image analysis. The results with the silica powder showed how the accuracy of the sedimentation methods depends strongly on a knowledge of the suspended particles hydrodynamic density. This can be effected greatly by particle or agglomerate porosity and the thickness of the electrical double layer in the aqueous dispersions investigated. The results with the silica suggest accuracy's on the size better than ±20% is difficult without an accurate hydrodynamic density whereas consistency between methods for narrow size distributions can be better than 5% for median volume diameters.     

A Simple Method of Evaluating Particle Size Distributions and Settling Rates for Silica Based Chromatographic Supports

Abstract

A simple and inexpensive method of evaluating particle settling rates and the particle size distribution of chromatographic supports using common laboratory equipment is reported. The time dependence of the turbidity of a solution of silica support particles suspended in an appropriate liquid is measured on a spectrometer. Digital acquisition allows data manipulation using simple algorithms to yield the distribution of particle sizes based on the Stoke's diameter. This data can easily be transformed into the most useful form for presentation, e.g. number average, weight average, cumulative distribution, etc.     

Influence of the grain size on the quality of standardless WDXRF analysis of river Nile sediments

In multichannel wavelength-dispersive X-ray fluorescence spectrometry (WDXRF) the fluorescence intensity might depend on grain size and heterogeneity of the sample. Six river Nile sediment samples were collected two meters below the water surface from different locations covering the greater Cairo, Egypt. Each sample was dried at 65 °C for 48 h and divided into four grain size fractions: < 32 μm, 32–63 μm, 63–125 μm and 125–200 μm using different sieves. The dry sediment samples were mixed with low contamination binder (Wax, C₆H₈O₃N₂) in a mass ratio of wax:sample = 4:0.9 g. Sample pellets were made using a hydraulic press at a pelletizing pressure of 120 KN cm^{− 2}. The results show that the XRF intensities of the K_α radiation might increase or decrease with decreasing grain size, depending on the atomic number of the analyte. In the present thick pelletized samples, the penetration depth of the characteristic radiation increases at low grain sizes, and consequently the probability of the grain-size effect on the characteristic radiation decreases. Depending on the experimental data, a general theoretical equation, relating fluorescence intensity, grain size and atomic number, was derived by using cubic spline interpolation. The fractions were identified by WDXRF using standardless quantitative analysis, depending on the fundamental parameter approach. According to the present statistical analysis and the Certified Reference Material (CRM) results, the quantitative analysis results were found acceptable when the grain size of the river Nile sediments less than 32 μm. At a grain size > 63 μm, standardless analysis using fundamental parameter approach was found to be useful for qualitative and semi-quantitative analysis only whereas there are a strong positive correlations.     

Y掺杂Ba0.90 Sr0.08 Ca0.02 TiO3固溶体纳米晶粒尺寸对其晶体结构的影响

随着电子陶瓷材料向精细、微型、多功能化的方向发展，陶瓷用的粉体晶粒尺寸对物性影响的研究显得越来越重要。钡系钙钛矿结构铁电材料是应用极为广泛的电子陶瓷材料，其铁电性与晶粒尺寸密切相关，尤其是达到纳米级时，可使材料性质发生奇异变化。迄今人们仅对纯ＢａＴｉＯ３超微细粒子的晶粒尺寸对铁电相变的影响进行了研究［１～３］，对稀土钇掺杂Ｂａ（１－ｘ－ｙ）ＳｒｘＣａｙＴｉＯ３固溶体纳米晶的相关研究报道尚少，而铁电尺寸效应对这类电子功能材料的研究、开发起着关键作用。因此，开展这方面的研究具有重要的学术价值和实际意…     

Use of a Cross-Sectional Model for Determining Rheology in Settling Slurries: Effect of Solvent,Particle Size,and Density

Transport models for partially settling slurries need accurate rheology correlations, particularly describing viscosity relationship to the particle concentration. A method is needed to untangle the effects of settling on apparent viscosity and the real effects of particle concentration on viscosity during rheology measurements. Our approach is based on model inversion of a cross-section model for the vertical particle concentration gradient and the local rheologies in the gap of a Couette type rheometer, established by a balance between gravitational particle settling and shear induced migration of the particles. The Krieger-Dougherty rheology correlation with adjustable parameters has been applied, where the parameters are determined by minimizing the difference between the measured viscosity data and those calculated by the model. Fairly mono-disperse silver coated polystyrene particles with two sizes and densities were used in both the aqueous and oil phase. In the raw data an apparent shear thinning tendency is observed. Through the model inversion process, this is accounted for by the shear dependent settling and the steep increase of viscosity with particle concentration. Maximum packing fraction was obtained through settling experiments. The difference between this value and the maximum packing fraction from the model inversion was less than 3% for oil-based suspensions. The larger difference was found for smaller particle size in water which is attributed to the larger effect of interparticle forces.