AAS测定紫皮石斛中5种重金属元素的含量

对天然紫皮石斛(Dendrobium devoninum Paxt.)根和茎中Cr、Cd、Pb、Hg、Cu 5种重金属元素的含量进行了测定,旨在为该资源的药(食)利用提供基础数据.利用干法灰化处理样品,采用原子吸收光谱法(AAS)分别测定紫皮石斛根和茎中Cr、Cd、Pb、Hg、Cu 5种重金属元素的含量.根中Cr、Hg和Cu 3种元素含量分别为122.8043士39.02、311.5152士24.28、0.2890士0.19mg·kg-1,相对标准偏差(RSD)在3.20％-14.07％之间;茎中Cr、Hg和Cu 3种元素的含量分别为139.3997士14.72、276.0101士45.61、0.2854士0.29mg·kg-1,相对标准偏差(RSD)在4.83％-10.99％之间;根和茎中均未检出Cd、Pb两种元素,可能与地球化学背景有关.与人工种植石斛中重金属元素含量相比,Cr、Hg两种元素含量相对较高,Cu元素含量较低.本法操作简便,重复性好,测定结果满意.

Determination of Five Heavy Metal Elements in Dendrobium devoninum Paxt.by AAS

The contents of Cd,Pb,Cr,Cu and Hg in the root and stem of Dendrobium devoninum Paxt.were determined,aiming to provide based data for medicine（food） using.After samples were processed by dry ash method,the contents of the five heavy metal elements Cd,Pb,Cr,Hg and Cu in the root and stem of Dendrobium devoninum Paxt.were determined by atomic absorption spectrometry （AAS）.The contents of Cr,Hg and Cu in roots were found to be 122.8043 + 39.02, 311.5152±24.28,0.2890±0.19mg · kg^-1,respectively,and the relative standard deviation（RSD） was 3.20%—14.07%.The concentrations of Cr,Hg and Cu in the stems were found to be 139.3997±14.72,276.0101±45.61,0.2854±0.29mg · kg^-1,respectively,and RSD was 4.83%—10.99%.Cd and Pb were not detected in the roots and stems possibly for the low concentration of the heavy metal elements in geochemical background.The concentrations of Cr and Hg in the Dendrobium devoninum Paxt.were higher than in the artificially planting,but the content of Cu was lower than that.The method is quick,simple and repeatability,and the results are satisfactory.