I've dosed mice with betanin and I'm trying to figure out how much of the betanin is going into the brain by using Mass Spectrometry and HPLC analysis. I've tried a protocol using 70% isopropanol for homogenizing the brain, centrifuging and then adding acetonitrile to the supernatant to precipitate protein out, centrifuging again, and then adding a 9:1 v/v chloroform/ methanol solution to the supernatant, another centrifugation step, and then rotovaping the liquid, and dissolving what's left in methanol. I wasn't able to detect any betanin in the sample using Mass Spec. So, either my protocol needs some tweaking (or a new protocol altogether), or the betanin concentration in the mouse brain is too low.

I've seen other protocols that use 10mM phosphate buffer for the homogenization step, so I'm inclined to use this. However, it would be really helpful to know if anyone has successfully extracted betanin or a similar molecule from mouse/ rat brains.