不同消解方法测定植株中磷含量的比较研究

目的]为实现植株中磷元素的快速监测,考察了不同消解前处理对试验结果的影响。方法]通过比较不同消解方法的准确度、精密度、试剂消耗量和所用时间,得出各方法的相对优劣。结果]以植株标准物质GBW10049、GBW10048和GBW07603为参照对象,微波消解和湿法消解法的结果误差分别为-0.12～0.05和-0.19～0.01,符合质控误差范围要求,采用干灰化法消解样品时,测定结果偏低,相对误差达到了8.2%。在植株中分别添加2个水平磷,微波消解法开展试验时平均回收率为102.3 %～108.3 %,相对标准偏差小于4.4%。文章还对影响光谱学性质的因素进行了讨论和优化,最终选择20 min为显色时间。结论]在最优条件下,磷浓度在0.1～1.0 μg/mL范围内具有良好的线性,线性相关系数大于0.9990,微波消解-分光光度法能用于实际植株样品中的检测。

Digestion Methods for Determining Phosphorus Content in Plants

Objective] The effect of different pretreatment on the test results was investigated, in order to determinate phosphorus in plants rapidly and accurately. Method] Four factors such as accuracy, precision, reagent consumption and the time spent were compared to obtain advantages and disadvantages among three kinds of methods. Result] The result error were respectively -0.12～0.05 and -0.19～0.01 with the pretreatment of microwave and wet digestion, when standard materials of plant GBW10049, GBW10048 and GBW07603 were taken as the reference objects. However, the determination result was low by using dry digestion with the relative error of 8.2%. Moreover, the recoveries of the phosphorus from plants were between102.3 % and 108.3%, and the relative standard deviation (RSD) was lower 4.4% when microwave digestion was applied. Factors affecting the spectroscopic properties were discussed, finally 20 min was chosen as color time. Under optimum conditions, good linearity was exhibited from 0.1 to 1.0 μg/mL with correlation coefficient of higher than 0.9990. Conclusion] The method was successfully applied for the analysis of phosphorus in real plants samples.