Yes, masala powders should ideally be stored away from pulses to prevent cross-contamination of flavors and aromas, and to maintain the freshness of both.
Masala powders, being finely ground and aromatic, are highly susceptible to absorbing odors from their surroundings. Pulses, while generally less aromatic, can still emit subtle earthy or bean-like scents. Storing them together can lead to the masala powders absorbing these scents, altering their intended flavor profile. This is especially true for delicate spice blends. Furthermore, pulses can sometimes harbor moisture, which can affect the quality and shelf life of the masala powders, potentially leading to clumping or even mold growth. Separating them ensures that each retains its original characteristics and stays fresh for longer. A good practice is to store masala powders in airtight containers in a cool, dark, and dry place, away from any strong-smelling ingredients, including pulses.
Label your spice containers clearly with the date of purchase or when you made the blend. This helps you keep track of their freshness and use them before they lose their potency.