Hi Chem forumers,
This might sound like a dumb question but does anyone know the difference between binary and quaternary HPLC?
Yes, that generally refers to the number of solvent inlet lines, a binary has two, and can program methods that mix two eluents, either isocratic or gradient, look those terms up. A quaternary can mix 4 eluents. You might use the extra eluents for a very complicated mixture, or a 3 component gradient, or to include wash solvents, or to just have 2 pairs of eluents, so you can pick and choose between 2 or more separations, without changing eluent bottles.
The HPLC itself can have one pump, which mixes from it's eluent bottles before the pump. Or it can have one pump per eluent, but that gets pricey, especially at 4 eluents.