"purchase supplies" is correct and usable in written English.
You can use it to express the action of buying materials needed for a task. For example, "We need to purchase supplies for the office party."
The government rebuilt its shattered armies and tried to purchase supplies from abroad.
Buying groups finance their operations through fees received from the companies they purchase supplies from.
Students are charged a laboratory fee each semester to provide funds necessary to purchase supplies and equipment.
The funds were used to purchase supplies that Hashmi helped deliver throughout the affected region.
The authority under this subsection may not be used to purchase supplies for resale.
The general contractor and subcontractors will then purchase supplies and materials.
Harrison tried to do everything expected of him, even trudging around Washington to purchase supplies for the White House.
Hospitals have long banded together to purchase supplies, contending that they could negotiate better prices as a group.
Hands-on engagement involves activities like making phone calls or taking trips to stores to purchase supplies.
Morton not only sent agents to purchase supplies for Indiana troops, including weapons and uniforms, but he also established a state arsenal to manufacture munitions.
Shops selling medical equipment, like wheelchairs and surgical knives, exist predominantly for patients to purchase supplies that a nearby public-sector hospital may not have.
