15 ILCS 510/6a

On or after the effective date of this Code, no State disbursing or auditing officer shall make or approve or take part in making or approving any payment for personal service to any person holding a position in the Office subject to this Code unless the payroll voucher or account of such pay bears the certification of the Treasurer, or of his authorized agent, that each person named therein has been appointed and employed in accordance with the provisions of this Code, and rules, regulations and orders thereunder.