原子吸收法测定牦牛奶粉中的营养元素

通过改变灰化温度，灰化时间及盐酸浓度三因素设计正交试验，对样品牦牛奶粉及市售奶粉进行干法消化。用火焰原子吸收光谱法对样品中的Ca, Mg, Fe, Cu, Zn, Mn, K和Na等八种元素进行测定。实验表明，最佳消化条件为：灰化温度510 ℃，灰化时间4 h，盐酸体积比为1∶5。在最佳实验条件下，对牦牛奶粉各元素的含量做了回收实验，回收率范围在95.2%～107.3%，相对标准偏差0.38%～3.86%(n=6)。实验结果表明：牦牛奶粉营养元素含量丰富, 是营养价值极高的食品。

Determination of Nutrition Elements in Yak Milk Powder by Atomic Absorption Spectrometry

In the present paper, orthogonal design test was planed by changing cinefaction temperature, cinefaction time, and the concentration of hydrochloric acid. Yak milk powder and milk powder were digested by dry method. The contents of elements Ca, Mg, Fe, Cu, Zn, Mn, K and Na were determined by flame atomic absorption spectrometry. The best conditions for the digestion were obtained as follows: the temperature was 510 degrees C, cinefaction time 4 hours, and hydrochloric acid concentration 1 : 5. Meanwhile, under the best experimental conditions, the recovery ratio of the method in the range of 95.2%-107.3%, and the relative standard deviations were 0.38%-3.86% (n=6). The experimental results proved that Yak milk powder is valuable and nutritious food, and has rich nutrition elements.