Lai Xuxin, Zheng Yiwu, Ipsen Henrik, Jacobsen Susanne, Larsen Jørgen N, Løwenstein Henning, Søndergaard Ib
Biochemistry and Nutrition Group, BioCentrum-DTU, Søltofts Plads, Technical University of Denmark, Kgs. Lyngby, Denmark.
Appl Spectrosc. 2007 Nov;61(11):1184-90. doi: 10.1366/000370207782596950.
A new method for particle size determination in polystyrene and aluminum hydroxide suspensions using near-infrared transmittance spectroscopy is described. Mono-dispersed polystyrene particle size standards were used to establish the calibration model. The particle sizes used in the study are similar to the wavelength range of 700-1300 nm, where light scattering is wavelength dependent. The wavelength dependency of near-infrared (NIR) absorbance is found to be linear with the particle size when the analysis is based on the same spectrum starting point (the same absorbance at 700 nm). Partial least squares regression (PLSR) is applied to model this linear relationship. Compared to laser diffraction (LD) the NIR method has similar accuracy and precision in the measurement of particles with a uniform size. For a sample containing multiple sizes of particles, the mean size measured by the NIR method is shown to be weighted by the particle mass. The application of the model to aluminum hydroxide suspension shows that the NIR method is suitable for the detection of particle size changes during the production process and storage. The advantages of the NIR method are that no knowledge of the refractive index and the concentration of a sample are necessary and that the method is fast and easy to operate.
描述了一种使用近红外透射光谱法测定聚苯乙烯和氢氧化铝悬浮液中粒径的新方法。使用单分散聚苯乙烯粒径标准物建立校准模型。研究中使用的粒径与700 - 1300 nm的波长范围相似，在此波长范围内光散射与波长相关。当分析基于相同的光谱起始点（700 nm处相同吸光度）时，发现近红外（NIR）吸光度的波长依赖性与粒径呈线性关系。应用偏最小二乘回归（PLSR）对这种线性关系进行建模。与激光衍射（LD）相比，NIR方法在测量均匀粒径的颗粒时具有相似的准确度和精密度。对于包含多种粒径颗粒的样品，NIR方法测得的平均粒径显示为按颗粒质量加权。该模型在氢氧化铝悬浮液中的应用表明，NIR方法适用于检测生产过程和储存期间的粒径变化。NIR方法的优点是无需了解样品的折射率和浓度，且该方法快速且易于操作。
