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板子在紫外灯下可以发出荧光，而一般有紫外吸收的物质在254nm为通用吸收波段，吸收了紫外光，就不能激发荧光，形成阴影，而不是显色。一般而言，TLC板(硅胶板)是在硅胶中加入了硅酸锌或硫酸镉的.常用的荧光剂是锰激活的硅酸锌,在254nm下产生荧光.而银激活的硫酸锌在365nm下产生荧光.