预胶化羟丙基淀粉中羟丙氧基含量测定方法的比较

Methods Comparison for Determination of Hydroxypropoxyl in Pregelatinized Hydroxyprop-yl Starch

目的:采用气相色谱法和紫外光谱法测定预胶化羟丙基淀粉中羟丙氧基的含量,并比较上述两种方法与核磁共振方法的测定结果。方法:气相色谱法采用Agilent DB-624(30 m×0.32 mm×1.8μm)柱,火焰离子化检测器(FID),通过测得2-碘丙烷的量折算得到羟丙氧基的含量;紫外光谱法:测定波长590 nm,通过测得丙二醇的量折算得到。结果:气相色谱法羟丙氧基的含量在1.4%~11.7%范围呈良好的线性关系(R^2=0.999 4,n=6),样品的平均加样回收率为100.1%(RSD=2.1%,n=9);紫外光谱法羟丙氧基的含量在1.5%~9.9%范围呈良好的线性关系(R^2=0.999 1,n=5)。结论:气相色谱法较紫外光谱法、核磁共振法更适用于预胶化羟丙基淀粉中羟丙氧基的含量测定。

Objective：To determine hydroxypropoxyl in Pregelatinized Hydroxypropyl Starch by GC and UV, and compare the results with that of by NMR.Methods：GC：The concentration of hydroxypropoxyl was determined and calculated by the content of 2-iodopro-pane.The separation was performed on an Agilent DB-624 capillary column（30 m ×0.32 mm ×1.8μm） with FID.UV：The detection wavelength was set at 590 nm, and the results were calculated by the content of 1,2-propanediol.Results：Good linear relationship was achieved when the content of hydroxypropoxyl was 1.4%-11.7% （R2 =0.9994,n=6） by GC, the average recovery was 100.1%（RSD=2.1%,n=9）.While when the content of hydroxypropoxyl was 1.5%-9.9% （R2 =0.9991,n=5）, the standard curve dis-played a good linearity by UV.Conclusion：Compared to UV spectrophotometry method and NMR,the GC method is proved to be more suitable for the determination of hydroxypropoxyl in Pregelatinized Hydroxypropyl Starch.