火焰原子吸收法测定海南槟榔叶片中金属元素的研究

严格按照田间采样方法采集海南槟榔园的叶片, 分别采用干灰化法和HNO₃-HCLO₄混合酸消煮法消化槟榔叶片，参考其他植物样品火焰原子吸收法的测定方法, 用火焰原子吸收光谱法测定了海南槟榔叶片中的K, Ca, Na, Mg, Fe, Mn, Cu, Zn金属元素的含量。研究了不同消化方法对测定金属元素含量的影响、仪器的最佳工作条件、干扰考察、并作了方法的准确度和精密度考察。干法消化的加标回收率在98.36%～102.38%之间，RSD在0.42%～2.33%(n=6)；湿法消化回收率在99.22%～103.72%之间，RSD0.58%～1.28%(n=6)。干法消化测定的八种金属元素含量稍低于湿法消化测定的含量，八种元素含量的比值在0.970 3～0.993 4之间。文章为槟榔叶片多种金属元素含量的测定提供了可靠的方法，方便了各种金属元素对槟榔的营养作用研究。

Study on Determination of Eight Metal Elements in Hainan Arecanut Leaf by Flame Atomic Absorption Spectrophotometry

Arecanut is a sort of palm that is important economic crop for the farmers in Hainan province of China, wherein there are many kinds of metal elements such as K, Ca, Na, Mg, Fe, Mn, Cu, Zn etc. These elements are important nutrition for the growth of arecanut. It is very valuable to study on the content of these metal elements in arecanut leaf in terms of plant nutriology of arecanut. The arecanut leaf in Wangling county, Hainan province of China was sampled by diagonal-field-sampling method. Refering to other plant sample determination by FAAS，the detailed studies are done with different digestion and determination methods. In the present paper the effects of mixed acid of HNO₃-HClO₄ digestion method on determining the amount of metal elements in the arecanut leaf by FAAS is reported, and another one is incineration digestion method. FAAS method was established for the determination of K, Ca, Mg, Na, Fe, Mn, Cu and Zn. The samples were incinerated or heated with HNO₃-HClO₄ (4∶1). In the meantime, the optimum parameters of FAAS and effects of different digestion methods on the results were discussed. The recovery rate of standard addition is 98.36%-102.38% in the first method; RSD is 0.42%-2.328%(n=6); The recovery rate of standard addition is 99.22%-103.72% in the second method; RSD is 0.58%-1.28%(n=6). The metal amount determined by the first method is lower than the second method, the ratio is 0.970 3-0.993 4. The two methods are satisfied, but the latter is better. It is precise enough to common experiment to use flame atomic absorption spectrophotometry with digestion by incineration. If the especially precise experiment is required, the digestion methods with mixed acid of HNO₃-HClO₄ may be introduced. The paper introduced methods dependable for determination of some metal elements in order to study on some nutrient effects of these metal elements in arecanut.