Silica with GF254

Silica with GF254 has an flourescent material that absorbs light at 254 nm (hence the 254 name) and emits in the visible spectrum. It works because many compounds also have some absorbance at 254 nm; this absorbance blocks a portion of the UV light from reaching the plate causing reduced fluorescence where the compound is located, making dark spots that we see.

 

GF254板子在紫外燈下可以發出熒光，而一般有紫外吸收的物質在254nm為通用吸收波段，吸收了紫外光，就不能激發熒光，形成陰影，而不是顯色。一般而言，TLC板(矽膠板)是在矽膠中加入了矽酸鋅或硫酸鎘的.常用的熒光劑是錳激活的矽酸鋅,在254nm下產生熒光.而銀激活的硫酸鋅在365nm下產生熒光.