预处理方法对植物生物质中钾元素含量测定的影响

采用干灰化法、湿式消解法和微波消解法对稻壳生物质进行了预处理,通过火焰原子吸收光谱法(FAAS)对不同预处理方法得到稻壳处理液中的钾元素含量进行了测定,为避免钾原子电离干扰的影响,加入了消电离剂.结果表明:加入500,μg/mL CsCl溶液可基本消除K+溶液测量过程中钾原子的电离干扰;稻壳样品经HNO3干灰化法、HNO3–H2O2湿式消解法和HNO3–H2O2微波消解法处理后,测定的稻壳中钾元素含量分别为0.638,4%、0.760,4%和0.778,6%;湿式消解法的实验结果重现性好,相对标准偏差仅为0.17%,且分析仪器简单,综合考虑,湿式消解法的效果优于干灰化法和微波消解法.

Effect of Pretreatment on the Measurement of Potassium Content in Plant Biomass

Potassium contents in the treated solutions obtained from rice husk after pretreatment, by using dry ashing, wet digestion and microwave digestion, were determined with flame atomic absorption spectrometry （FAAS）. In order to avoid ionization interference of potassium atoms, a deionization agent was added to the treated solutions. The results show that 500 μg/mL CsC1 could almost eliminate the potassium atom ionization interference. Potassium content in the rice husk pre- treated through dry ashing by using HNO3 was 0.638 4%. However, the potassium contents in the treated rice husk through wet digestion and microwave digestion were 0.760 4% and 0.778 6%, respectively. The experimental values of potassium content derived from wet digestion were well reproducible and highly stable, and the relative standard deviation （RSD） of the data was only 0.17%, Wet digestion method is suggested all because the required instrument for wet digestion was simpler and more facilitating compared to the others.