激光光热折射光谱法及其差分构型的研究

Investigation of Photothermal Refraction Spectrometry and Its Differential Configuration

本工作借助于透镜对探测束发散的会聚补偿作用,设计了一个光热折射光谱的差分式光路构型,可以有效地消除溶剂空白吸收的影响和泵浦激光强度起伏与指向噪音的影响。本差分构型光路简单,容易实现样品池和参考池的定位与调整。文章还详细讨论了光热折射光谱法的实验参数,获得的结晶紫和钴的检测下限分别为1.0×10^(-9)mol/L和0.28 μg/ml,对应的最小吸光度为1.5×10^(-8)和2.5×^(-7)。

A configuration of differential photothermal refraction was presented by using a focal lens for compensation of the divergence of the probe beam. it eliminatce the solvent effect on the absorpiton and intensity fluctuation and point noise in pump source. This configuration of the optical system is simple ,and,the adjustment of the sample and the reference cell is achieved easily. The detailed experimental parameter of photothermal refraction spectrometry was discussed. The detection limit of 1. 0×10-9 mol/L for crystal violet and 0. 28 μg/ml for cobalt was obtained , respectively , which correspond to minimum measurable ab-sorbance of 1. 5 × 10-8 and 2. 5 ×10-7 ,respectively.