Only a limited types of LC-MS CHROMASOLV?grade solvent are available, such as EtOAc, MeOH, i-PrOH and MeCN. Is it necessary to use them while other mobile phase components (like water, buffer) are only available in HPLC grade?

Hi Anonymous,
I currently use an LC-MS method for detection and quantitation of herbicide residues in waters; for this, and other methods too, I use acetonitrile gradient grade from Merck and MilliQ grade water (produced in-house) without problem.
I have also tested methanol gradient grade from Merck with good results.
LC-MS grade are probably referred as very low content of sodium, but it is important to test a solvent in your analytical asset (LC method, MS instrument,...) and verify the performance obtained.
I hope this information is useful for you.

Almost all of the LC/MS users in our lab only use Burdick and Jackson solvents and water. However, they are working with small masses, usually less than 300 AMU, and at very low levels.

If you can use MilliQ water, it MIGHT save you money. But what happens when the cartridges get changed, or something else happens, and suddenly analyses that once worked, don't? You could spend days tracking down the problem. Unless you are using huge quantities of water, it is probably not worth the risk. And just to be safe, you probably already have a small supply of 'good' water stashed---or you should!