The purchasing agent, under the supervision of the county board, or the county board, if there is no purchasing agent, shall purchase all personal property and services required by any office, officer, department, or agency of the county government in the county, subject to the County Purchasing Act. The purchasing agent or the county board, if there is no purchasing agent, shall draw up and enforce standard specifications which shall apply to all personal property purchased for the use of the county government, shall have charge of all central storerooms operated or established by the county board, and shall transfer personal property to or between the several county offices, officers, and departments. All purchases of election ballots and election contractual services shall be made by the election commissioner or by the county clerk in counties without an election commissioner.