大米中微量金属元素含量的测定

Determination of Trace Metal Elements in Rice

采用干化灰化、湿式消解、非完全消化法分别对贵州、湖北的大米进行预处理,用火焰原子吸收光谱法测定其中Fe、Zn、Ca、Mg、Cu、Cd 6种微量金属元素的含量。结果:3种方法预处理后的贵州大米中Fe、Zn、Mg、Cu、Cd 5种微量金属元素的含量均高于湖北大米,但湖北大米中Ca含量稍微高于贵州大米。贵州大米中Fe、Zn、Ca、Mg、Cu、Cd的含量分别为:26.783~39.003μg·g^(-1)、21.340~27.715μg·g^(-1)、43.260~51.750μg·g^(-1)、168.180~216.390μg·g^(-1)、3.003~4.209μg·g^(-1)、0.562~0.661μg·g^(-1),湖北大米:18.510~19.473μg·g^(-1)、19.802~24.118μg·g^(-1)、44.640~52.560μg·g^(-1)、75.440~83.570μg·g^(-1)、2.875~3.285μg·g^(-1)、0.287~0.457μg·g^(-1)。各元素检出限分别为0.0921μg·m L-1、0.0040μg·m L-1、0.0884μg·m L-1、0.0018μg·m L-1、0.0087μg·m L-1、0.0032μg·m L-1,精密度范围分别为:1.59%~4.51%、0.63%~2.86%、2.55%~4.56%、0.52%~2.12%、4.46%~9.29%、5.96%~19.51%。相关系数范围:0.9990~0.9998。

The method of dry ashing,the wet digestion and the incomplete digestion have been adopted to preprocess the rice produced in Guizhou and Hubei respectively to detect 6 kinds of trace metal elements,namely Fe,Zn,Ca,Mg,Cu,Cd,by flame atomic absorption spectrometry（FAAS）. As a result,the rice produced in Guizhou has higher trace metal elements contents of Fe,Zn,Mg,Cu,Cd by the three digestion methods than Hubei＇s,while the contents of Ca in Hubei rice were somewhat higher than Guizhou rice ＇s. The contents of Fe,Zn,Ca,Mg,Cu,Cd in Gui Zhou rice were 26. 783 - 39. 003μg·g^-1,21. 340 - 27. 715μg·g^-1,43. 260 - 51. 750μg·g^-1,168. 180 - 216. 390μg·g^-1,3. 003 - 4. 209μg·g^-1,0. 562 - 0. 661μg·g^-1,while in Hu Bei rice＇s were 18. 510 - 19. 473μg·g^-1,19. 802 - 24. 118μg·g^-1,44. 640 - 52. 560μg·g^-1,75. 440 - 83. 570μg·g^-1,2. 875 - 3. 285μg·g^-1,0. 287 - 0. 457μg·g^-1. The limits of various elements were 0. 0921μg·m L^-1,0. 0040μg·m L^-1,0. 0884μg·m L^-1,0. 0018μg·m L^-1,0. 0087μg·m L^-1,0. 0032μg·m L^-1. The precision of six elements were 1. 59% - 4. 51%,0. 63% - 2. 86%,2. 55%- 4. 56%,0. 52% - 2. 12% 4. 46% - 9. 29%,5. 96% - 19. 51%,respectively. The correlation coefficient ranged from 0. 9990 to 0. 9998.