碳酸氢钠浸提-稀盐酸酸化-ICP-AES法测试石灰性土壤有效磷

Determination of Available Phosphorus in Calcareous Soils by Sodium Bicarbonate Extraction-Bilute Hydrochloric Acid Acidif ication-ICP-AES Method

在农业标准NY/T 1121.7—2014基础上,文章对石灰性农业土壤中的有效磷的测试方法做了部分优化。首先将石灰性农业土壤用碳酸氢钠溶液浸提,然后利用稀盐酸(1∶1)酸化,最后利用电感耦合等离子发射光谱法测定。对实验条件浸提时间、水和土比例、有色滤液稀释方式、浸提温度等做了比较分析。最终确定水土比在10∶1,振荡时间30 min,浸提温度为20~25℃,滤液用1.0 mol/L稀HCl溶液稀释,用电感耦合等离子体发射光谱法直接测定样品溶液中有效磷。此方法检出限(3 s)为0.15 mg/kg,加标回收率在92%~103%之间,测定值的相对标准偏差(n=12)为2.3%。该方法较农业部标准NY/T 1121.7—2014分析节约了试剂的使用量,减少了对环境的污染,方法效率提高,过程得到简化,结果可靠稳定。

This method is based on agricultural standard NY/T 1121.7—2014,to investigate the extraction of available phosphorus in neutral and calcareous agricultural soils with Sodium bicarbonate solution,acidif ication with dilute hydrochloric acid,and the determination of available phosphorus by inductively coupled plasma-atomic emission spectrometry(ICP-AES),the effects of oscillation time,water-soil ratio,dilution method of colored f iltrate and extraction temperature on the extraction results were studied.The detection limit(3 s)was 0.15 mg/kg,the recoveries were 92%-103%,and the relative standard deviation(RSD)was 2.3%.Compared with the standard of NY/T 1121.7—2014,this method can save the use of reagents,reduce the pollution to the environment,improve the eff iciency of the method,simplify the process and obtain reliable and stable results.