Fig. (2) FTIR spectra of the synthesized compounds in buffered media. TA: Tannic acid; A1: TA-Cu(II), pH 5,5, in 1:1 ratio; A2: TA-Cu(II), pH 5,5 in 1:5 ratio; A3: TA-Cu(II), pH 8,0 in 1:1 ratio; A4: TA-Cu(II), pH 8,0 in 1:5 ratio; A5: TA-Zn(II), pH 5,5, in 1:1 ratio; A6: TA-Zn(II), pH 5,5 in 1:5 ratio; A7: TA-Zn(II), pH 8,0 in 1:1 ratio and A8: TA-Zn(II), pH 8,0 in 1:5 ratio.