Gradient Types


Similar to traditional ion separation, the buffer concentration plays an important role in the mixed-mode technology altering the degree of ionic interaction of the biomolecules with the stationary phase. The amount of the organic modifier is also important in changing the degree of hydrophobic interaction. Independent adjustment of the amount of buffer and organic modifier creates an infinite number of separation conditions that are suitable for many types of biomolecules. Generally three types of gradient separation modes are available on Promix columns: A gradient of MeCN with an isocratic buffer concentration, a gradient of buffer concentration with an isocratic MeCN concentration, and a dual gradient of both MeCN and buffer.