The County Purchasing Law of 1957, T.C.A. § 5‑14‑101 et seq., and the 1981 Financial Management Act, T.C.A. § 5‑21‑101 et seq., both contain conflict of interest provisions more stringent than the general conflict of interest statute.  The 1957 Act and the 1981 Act are optional general laws which may or may not be in effect in a particular county.