Abstract

For the first time, pharmaceutical tablet coating thickness is measured by combined Raman spectrometry (RS) and laser induced breakdown spectrometry (LIBS) techniques. Measurements by two methods (RS and LIBS) are performed during a single pump lamp flash of a pulsed Nd:YAG laser in the double pulse lasing mode. This approach combining a probe laser pulse (RS) followed by an ablating laser pulse (LIBS) allows depth profiling analysis. An additional advantage is a possible comparison of the results of measurements of molecular and elemental compositions within the same spot. It is shown that the published method for measuring the coating thickness by LIBS depth profiling leads to systematic errors. An approach for improving the accuracy of coating thickness data measurements by comparing the RS and LIBS is proposed.

中文翻译：

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拉曼光谱和激光诱导击穿光谱技术相结合的片剂包衣厚度测量

摘要

药物片剂包衣厚度首次通过拉曼光谱（RS）和激光诱导击穿光谱（LIBS）技术进行测量。在双脉冲激光模式下，在脉冲Nd：YAG激光器的单次泵浦灯闪烁期间，通过两种方法（RS和LIBS）进行测量。这种结合了探测激光脉冲（RS）和消融激光脉冲（LIBS）的方法可以进行深度轮廓分析。另一个优点是可以比较同一点内分子和元素组成的测量结果。结果表明，已公开的通过LIBS深度轮廓测量涂层厚度的方法会导致系统误差。提出了一种通过比较RS和LIBS来提高涂层厚度数据测量精度的方法。