摘要
土壤有效钼含量测定对评价土壤钼对作物的有效性和土壤钼供应水平具有重要意义。目前常用极谱法和石墨炉原子光谱法测定土壤有效钼,但因操作复杂,多有不足和不便。采用草酸-草酸铵溶液浸提土壤有效钼,不经分离与富集,采用电感耦合等离子体质谱仪He碰撞模式测定浸提液中钼(95Mo),以103Rh为内标元素。结果表明:方法检出限为1.02μg/L;2个国家土壤标准物质(GBW07413a黄潮土和GBW07416a红壤)有效钼的测定值与标准确认值一致;加标回收率在95.1%~152%之间;对5个土壤样品分别重复测定6次,相对标准偏差小于8%。结论认为电感耦合等离子体质谱仪He碰撞模式可以用于测定草酸-草酸铵浸提的土壤有效钼,该方法测定结果准确,重现性好,快速方便。
Molybdenum （Mo） is an essential element of plants. Rational Mo fertilizer application to soil requires information of the Mo concentrations in soil. Determination of soil available Mo has great significance in evaluating the soil Mo supply. Mo concentration in extract is often determined with graphite furnace atomic absorption spectrometry or pelarography methods, which are not easily operated and consume time. In this paper, oxalic acid-oxalate ammonium solution （pH 3. 3, Tamm rea- gent） was used as extraction solution to extract available Mo form in soil. The Mo in the extract of Tamm solution was deter- mined directly by the inductively coupled plasma mass spectrometry （ICP-MS） with collision model using high pure helium （He） gas. t^3Rh was used as an internal standard element to correct the matrix effect. The results showed that the detection limit of the proposed method was 1.02 tLg/L. The measured soil available Mo values were consistent with the standard values of two national soil standard materials （GBW）. The recovery rate was in ranges of 95.1% - 152% when adding the standard Mo solution to the soil. The relative standard deviation of determinations for 5 soil samples with 6 repeats per sample was less than 8%. It is suggested that ICP-MS with He gas collision mode could be used for determining soil available Mo extracted by Tamm reagent. The proposed method saves time and is suitable for the batch measurement of soil samples.
出处
《中国土壤与肥料》
CAS
CSCD
北大核心
2017年第6期171-175,共5页
Soil and Fertilizer Sciences in China
基金
中央级公益性科研院所基本科研业务费专项(Y2017PT14)
国家重点研发计划项目(2016YFD0200108)
关键词
电感耦合等离子体质谱仪
土壤有效钼
inductively coupled plasma mass spectrometry
soil available molybdenum
