草酸钙结石形态的红外光谱分析

Analysis of Calcium Oxalate Crystalline Phases by Infrared Spectrophotometry

草酸钙结石主要是以一水草酸钙(COM)、二水草酸钙(COD)的形式存在。在解决缺少COD标样的难题后,将制备的COD样品与COM标样混合,然后采用红外光谱法对混合物进行分析研究,采用谱带比值法,确定了COD和COM在660和610 cm-1处与780和520 cm-1处的吸收度比值(R)与质量分数(w)的关系式,其线性回归方程分别为:R=11.95×10-3wCOD+0.873 61,r=0.983 63;R=4.74×10-3wCOD+0.886 52,r=0.992 44。同时为了减少压片、测定等因素引起的误差,采用零点交叉一阶导数法,测定在1 320 cm-1处吸收度一阶导数与COD质量分数(w)的关系式,其线性回归方程I=5.5×10-5w+9.2×10-5,r=0.996 60。线性良好。

Calcium oxalate occurs mainly as two different phases： calcium oxalate monohydrate（COM） and calcium oxalate dihydrate（COD）. After the COD standard sample for the analysis was synthesized, mixed the COM and COD, then used infrared spectrophotometry to study the mixture. Apply the absorbance ratio of 660 -610 cm^-land 780 -520 cm^-1（COD/COM） , two equation of linear regression： R = 11.95 × 10^-3 wCOD ＋0. 873 61, r =0. 983 61 ; R =4. 74 ×10^-3 wCOD ＋0. 886 52, r =0. 992 44 is obtained. To make the proportions more accuracy, a linear regression equation： I =5.5 × 10^-5 wCOD＋ 9. 2 × 10^-5, r =0. 996 60 for the intensity of the first-derivative infra-spectrum at 1 320 cm^-1 with the concentration of the COD is obtained. The method revealed to be easy, accrate.