Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
Anal Chem. 2022 Sep 27;94(38):13100-13107. doi: 10.1021/acs.analchem.2c02358. Epub 2022 Sep 13.
Autofluorescence-detected photothermal mid-infrared (AF-PTIR) microscopy was shown to enable parts-per-million detection of α-indomethacin impurity in γ-indomethacin samples. Subtle differences in the photothermal response of the UV-autofluorescence of two indomethacin crystal polymorphs were used for sub-micron chemical discrimination based on fingerprint region mid-IR spectroscopy. The AF-PTIR assignment was independently confirmed by second harmonic generation (SHG) microscopy, which was shown to reduce the total analysis time by rapidly identifying the suitable fields of view. AF-PTIR microscopy has the potential to assist in the early identification of crystal form impurities in the solid dosage forms development pipeline.
自发荧光探测光热中红外（AF-PTIR）显微镜被证明能够检测到 γ-吲哚美辛样品中百万分之几的 α-吲哚美辛杂质。两种吲哚美辛晶型的紫外自发荧光的光热响应的细微差异被用于基于指纹区中红外光谱的亚微米化学鉴别。AF-PTIR 分配通过二次谐波产生（SHG）显微镜得到独立确认，SHG 显示通过快速识别合适的视场来减少总分析时间。AF-PTIR 显微镜有可能在固体剂型开发管道中协助早期识别晶型杂质。
