藏药佐太的化学成分、汞配位结构及微观形貌分析

摘要

In order to reveal the chemical substance basis of pharmacodynamic effects of Zuotai ,energy dispersive spectrometry of X‐ray (EDX) ,X‐ray fluorescence spectroscopy (XRF) ,synchrotron radiation X‐ray absorption fine structure (SR‐XAFS) , X‐ray diffraction (XRD) ,scanning electron microscope (SEM ) and atomic force microscope (AFM ) were used to analyze the el‐ements ,the chemical valence and local structure of mercury ,and the chemical phase composition and micro‐morphology of Zuo‐tai .EDX and XRF analysis shows that the main elements in Zuotai are Hg and S ,with some other minor elements ,such as O , Fe ,Al ,Cu ,K ,Ag ,Ca ,Mg etc .SR‐XAFS analysis shows that :the oxidation state of mercury in Zuotai is divalence ,its neighbor atoms are S ,and its coordination number is four .XRD assay found that β‐HgS (cubic ,F‐43m 216) and S8 (ortho‐rhombic ,Fddd 70) are the main phase compositions in Zuotai .Besides ,it also has a small amount of C (hexagonal ,P63/mmc 194) ,Fe1.05 S0.95 (hexagonal ,P63/mmc 194) ,Cu6S6 (hexagonal ,P63/mmc 194) ,Cu1.8 S (cubic ,F‐43m 216) and so on .And it was found that the crystallinity of Zuotai is about 59% ,and the amorphous morphology substance in it is about 41% .SEM and AFM detection suggests that Zuotai is a kind of ancient micro‐nano drug ,and its particle size is mainly in the range of 100~600 nm ,even less than 100 nm ,which commonly further aggregate into several to 30 μm loose amorphous particles .In summary , the present study elucidated physicochemical characterization (elements composition ,coordination information of mercury ,phase composition and micro‐morphology) of Zuotai ,and it will play a positive role in promoting the interpretation of this mysterious drug .%佐太是一种古老的传统藏药，由水银、硫磺、八金、八矿等原辅料炮制而成，主要用来配制多种珍宝类藏药制剂。佐太作为含重金属藏药的典型代表，安全性与有效性一直备受质疑，而探明佐太的精确理化表征，则是科学阐释该疑问的重要切入点。该研究采用X射线能谱（EDX）、X射线荧光谱（XRF）、同步辐射X射线吸收精细结构（XAFS）、X射线衍射（XRD）、扫描电子显微镜（SEM ）、原子力显微镜（AFM ），对佐太的元素组成、汞的化学价态与配位结构、物相成分与空间结构、微观形貌进行系统分析。EDX和XRF结果发现，佐太中主要元素为 Hg和S ，另外还有少量的O ，Fe ，Al ，Cu ，K ，Ag ，Ca ，Mg等元素。XAFS分析发现，佐太中Hg是以正二价形式存在，配位数为4，配位原子为S。XRD结果发现，佐太中存在立方晶系β‐HgS（空间群为F‐43m 216）、斜方晶系单质硫S8（空间群为Fddd 70），以及少量的六方晶系C（空间群为P63／mmc 194）、六方晶系Fe1.05 S0.95（空间群为P63／mmc194）、六方晶系Cu6 S6（空间群为P63／mmc 194）、立方晶系Cu1.8S（空间群为F‐43m 216）等；另还发现，佐太的结晶度约为59％，无定型态物质约占41％。SEM和A FM分析发现，佐太应为古代微纳米药物，其微粒多在100～600 nm ，并有不少低于100 nm ，这些微粒常堆聚成1～20μm松散的无定型态颗粒。本研究探明了佐太的元素组成、汞的配位信息、物相成分和微观尺寸特征等，对科学解读神秘藏药———佐太的生物效应具有重要的启发。