Spanish to English Medical Medical: Pharmaceuticals

From the description of the process of preparation of a plasma pool for a lyophilized immunoglobulin powder:

"La fracción IgG se recoge en un tanque sanitizado hasta que la cola de elución de IgG tenga la mitad o dos tercios de la **altura máxima del pico**."

My attempt:

"The IgG fraction is collected in a sanitized tank until the IgG elution tail is at half or two thirds the maximum peak height [?]".

I'm not certain of my translation of "altura máxima del pico", or of what the term refers to. Any advice from experts in the field would be greatly appreciated.