Span 85 has shown characteristic peaks at 2923.18 cm-1, 2853.50 cm-1 both peaks represent (double bond CH2), 1743.05 cm-1 ( ketone with 5 membered cyclic ring), 1463.44 cm-1 (scissoring double bond CH2), 1377.42 cm-1 (CH3), 1167.75 cm-1 (CO str) and 1090.63
cm- 1 (CO strong)[19].