微波消解-电感耦合等离体子质谱法(ICP-MS)同时测定畜禽粪便中7种重金属元素

粪便样品干燥、研磨后,称取0.25 g样品,加入8 mL硝酸,采用微波消解方法进行前处理。采用KED模式消除质谱干扰,采用内标校正消除非质谱干扰(Ge作为Cu、Zn、Cr的内标,Bi作为Hg和Pb的内标,Rh作为As和Cd的内标),建立了可同时测定畜禽粪便中Cu、Zn、Cr、As、Cd、Pb、Hg 7种重金属元素的微波消解-电感耦合等离子体质谱法。方法线性相关系数均在0.9995以上,检出限为0.005~0.305μg/L,加标回收率为83.6%~112%,相对标准偏差为0.70%~5.6%。方法灵敏度、准确度和精密度高,实用性强,适用于同时检测畜禽粪便中多种重金属元素,对畜禽粪便的科学还田具有指导意义。

Simultaneous Determination of Seven Heavy Metal Elements in Livestock Manure by Microwave Digestion and ICP-MS

After the livestock manure samples were dried and ground,0.25 g of samples was weighed,then added 8 mL nitric acid.Microwave digestion was used for the pretreatment of the samples.We used KED mode to eliminate the mass spectrum interference.And internal standard correction was used to eliminate non-mass spectrum interference(germanium as internal standard of cuprum,zinc and chromium,bismuth as internal standard of hydrargyrum and plumbum,rhodium as internal standard of arsenic and cadmium).The method of microwave digestion and ICP-MS was established which could conduct the simultaneous determination of seven heavy metal elements of cuprum,zinc,chromium,arsenic,cadmium,plumbum and hydrargyrum in livestock manure.The linear correlation coefficients of the method were all above 0.9995.The detection limit was in the range of 0.005~0.305μg/L.The recovery rate was between 83.6%and 112%.The relative standard deviation was between 0.70%and 5.6%.The method had high sensitivity,accuracy,precision and practicability and it was suitable for simultaneous detection of multiple heavy metal elements in livestock manure which had guiding significance for scientific return of livestock manure to field.