Table 4.

Change of IR absorption band in treatments of metals and the possibly corresponding groups

Original main band wave numbers (cm−1)	Changed main band wave numbers (cm−1)		Functional groups
	50 ppm	100 ppm
3292.8	3296.45	3292.73	–NH
2956.44	2959.24	2960.32	–CH
2924.52	2924.17	2926.30	–CH
2855.36	2852.94	2854.90	–CH2
1648.0	1650.77	1652.57	–C=O
1541.33	1536.09	1537.40	–COO, –NH, –CH
1450.02	1451.53	1452.98	–CH2
1399.11	1401.20	1400.98	–H
1236.27	1238.10	1233.80	–COOH, –PO
1072.57	1073.14	1068.01	–CO, –CN, –PO
534.92	544.57	548.19	–