归属分析了明胶在鞣性金属离子Ｃｒ（Ⅲ）、Ａｌ（Ⅲ）、Ｌｎ（Ⅲ）（其中Ｌｎ＝Ｌａ，Ｃｅ，Ｐｒ，Ｎｄ，Ｅｒ，Ｙ）作用前后的红外光谱图。结果表明：明胶的红外光谱特征与其在络合物中相比，位置与相对强度皆发生了明显的变化。明胶侧链羧基基团的对称伸缩振动吸收峰（１４１０ｃｍ－１）在固体络合物中位移至１４２０ｃｍ－１左右，且Δν（νａｓＣＯＯ－－νｓＣＯＯ－）在２００～２２０ｃｍ－１之间，说明羧基以双齿方式发生配位作用。图３，表１，参考文献１０ The infrared spectra of gelatin before and after the tanning metal ions Cr (Ⅲ), Al (Ⅲ) and Ln (Ⅲ) (including Ln = La, Ce, Pr, Nd, Er, Y) were analyzed. The results show that the infrared spectra of gelatin have obvious changes compared with those in the complex. The symmetrical stretching vibrational absorption peak (1410cm-1) of the carboxyl group of the gelatin side chain is shifted to about 1420cm-1 in the solid complex and the Δν (νasCOO - νsCOO-) is between 200 and 220cm-1, indicating that the carboxyl group Bidentate way to occur coordination effect. Figure 3, Table 1, Reference 10