荆芥不同部位3种重金属元素含量的比较分析

Comparative analysis of three heavy metal elements in different parts of Schizonepeta tenuifolia Briq.

测定荆芥药材不同药用部位中铅(Pb)、镉(Cd)、镍(Ni)3种重金属元素的含量,比较分析荆芥不同部位的污染状况.对荆芥样品进行湿法消解,采用石墨炉原子吸收光谱法(GFAAS)测定样品中Pb、Cd、Ni含量,以质量分数2%磷酸二氢铵-1.67%硝酸镁作为基体改进剂测定Pb、Cd;以质量分数0.2%硝酸钯-2%磷酸二氢铵作为基体改进剂测定Ni.Pb、Cd、Ni的测定波长分别为283.3、228.8和232.0nm,灯电流分别为10、6和25mA;狭缝分别为0.7、0.7和0.2L.Pb、Cd、Ni元素线性关系分别为Y=0.002 8 X+0.002 7(r=0.998 9)、Y=0.034 8 X+0.005 4(r=0.998 3)和Y=0.002 9 X+0.004 3(r=0.998 4),回收率为98.2%～102.9%;荆芥梗中Pb、Cd和Ni的质量分数测定结果分别为0.55～0.95、0.05～0.11和0.1～1.22mg/kg;荆芥穗质量分数测定结果分别为0.58～1.73、0.03～0.14和0.18～1.42mg/kg.重金属元素Pb、Cd、Ni检测方法可靠,随着采收时间延长,重金属元素易由荆芥梗向荆芥穗中富集,为荆芥重金属限度质量标准制定以及临床用药部位的选择提供参考.

The contents of lead(Pb),cadmium(Cd)and nickel(Ni)in different medicinal parts of Schizonepeta tenuifolia Briq.(STE)were determined.Meanwhile,the contamination status of STE was compared and analyzed.After pretreatment by wet digestion system,Pb,Cd and Ni were determined by graphite furnace atomic absorption spectrometry(GFAAS).2%NH4H2PO4-1.67%Mg(NO3)2 were used as a matrix modifier to determine Pb and Cd;and 0.2%Pd(NO3)2-2%NH4H2PO4 was used as a matrix modifier to determine Ni.The determination condition was as follows.The wavelengths of Pb,Cd,Ni were 283.3,228.8,and 232.0 nm;lamp currents were 10,6,and 25 mA,respectively.Entrance slits were 0.7,0.7,and 0.2 L,respectively.Calibration curves of three elements(Pb,Cd,Ni)were Y=0.002 8 X+0.002 7(r=0.998 9),Y=0.034 8 X+0.005 4(r=0.998 3),Y=0.002 9 X+0.004 3(r=0.998 4),respectively.The recovery values were 98.2%-102.9%.The results of content determination of STE’s stem were 0.55-0.95,0.05-0.11 and 0.1-1.22 mg/kg,respectively.The results of content determination of STE’s ears were 0.58-1.73,0.03-0.14 and 0.18-1.42 mg/kg.The detection methods of heavy metal elements Pb,Cd and Ni are reliable.With the prolongation of harvest time,heavy metal elements are easily enriched from STE’s stem to STE’s ears.This paper provides a reference for the development of limit standards of heavy metals in STE and the selection of clinical drug sites.