不同来源龙齿药材中4种重金属含量的分析

目的:测定不同来源龙齿药材中铅(Pb)、镉(Cd)、汞(Hg)、砷(As)4种重金属的含量。方法: 对龙齿样品进行湿法消解后,采用石墨炉原子吸收光谱法(GFAAS)测定龙齿样品中Pb、Cd、As含量,以1%磷酸二氢铵＋0.06%硝酸镁作为基体改性剂,Pb、Cd、As的测定波长分别为283.3、228.8、193.7 nm,灯电流分别为10、8、130 mA,狭缝均为0.7 nm。以硼氢化钠作为还原剂的冷蒸气原子吸收光谱法(CVAAS)测定Hg含量,测定波长253.7 nm,灯电流140 mA,狭缝0.7 nm,延迟时间5 s。结果: Pb、Cd、Hg、As元素测定方法线性关系分别为Y=0.001 9X+0.008 8(r=0.999 0)、Y=0.025 3X+0.014 6(r=0.998 5)、Y=0.012 8X+0.001 6(r=0.999 7)、Y=13.01X+0.813 2(r=0.999 4),RSD均小于3%,回收率为90.7%~112.7%;含量测定结果分别为0.58~6.27、0.04~2.89、0.26~1.16、0.09~0.88 mg·kg^-1。结论: 不同来源的龙齿药材中4种重金属含量不同,其中Pb含量是4种重金属中最高的。经方法学验证,本法为制定龙齿重金属限度质量标准提供了参考。

Objective: To determine the content of four heavy metals (Pb, Cd, Hg, As)in Dens Draconis from different sources. Methods: After pretreatment by wet digestion system, Pb, Cd, and As were determined by graphite furnace atomic absorption spectrometry (GFAAS)with 1% NH₄H₂PO₄＋0.06% Mg(NO₃)₂ as the matrix modifiers.The determination condition was as follows.The wavelengths of Pb, Cd, As were 283.3, 228.8, and 193.7 nm;lamp currents were 10, 8, 130 mA, respectively.Entrance slits were 0.7 mm.Hg was determined by cold vapour atomic absorption spectrometry (CVAAS)with NaBH₄ as the reductant, the measuring wavelength was 253.7 nm.The lamp current was 140 mA, the entrance slit was 0.7 nm, and the delay time was 5 s. Results: Calibration curves of four elements (Pb, Cd, Hg, As)were Y=0.001 9X+0.008 8(r=0.999 0), Y=0.025 3X+0.014 6(r=0.998 5), Y=0.012 8X+0.001 6(r=0.999 7), Y=13.01X+0.813 2(r=0.999 4), respectively.RSD were < 3%.The recovery values were 90.7%-112.7%.The results of content determination were 0.58-6.27, 0.04-2.89, 0.26-1.16, 0.09-0.88 mg·kg ^-1, respectively. Conclusion: The content of four kinds of heavy metals from different sources of Dens Draconis is different and Pb is the highest of them.The validated method successfully provides a reference for the development of limit standards of heavy metals in Dens Draconis.