Hi, May I know, what factors should I look up to choose my buffer solution?  I want to make buffer in pH 11 and pH 9.. can i choose one pH with phosphate buffer and the other one with borate buffer?

Can we done our experiment with different buffer systems? For example, at pH 8 , i used phosphate buffer to determine the CMC of my product, while at pH 10, I used borate buffer to determine CVC. 

Thanks for your help in advance