不同消解方法测定植株中磷含量的比较研究

Digestion Methods for Determining Phosphorus Content in Plants

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。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。结果表明: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,最终选择显色时间为20 min。在最优条件下,磷浓度在0.1~1.0μg/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-分光光度法可用于实际植株样品检测。

The effect of different pretreatments on rapid and accurate determining of phosphorus in plants was investigated. Four factors, including accuracy, precision, reagent consumption and used time, were compared to weigh the advantages and disadvantages of three test methods. The results showed that taking plant standard substance GBW10049, GBW10048 and GBW07603 as the reference objects, the result error with the pretreatment of microwave and wet digestion was respectively-0.12-0.05 and-0.19-0.01, conformed to the error range of quality control. However, the determining result was low by using dry digestion, whose relative error was 8.2%. Moreover, when 2 levels of phosphorus were added to the plants, the recovery of phosphorus from plants with microwave digestion was between 102.3% and 108.3%, and the relative standard deviation(RSD) was lower than 4.4%. Factors affecting the spectroscopic properties were discussed, and finally, 20 min was chosen as the coloration time. Under the optimum condition, good linearity was exhibited from phosphorus content of 0.1 to 1.0 μg/mL, the correlation coefficient was higher than 0.9990. The microwave digestion spectrophotometry method could be applied to the analysis of phosphorus in plant samples.