基于EPMA的背角无齿蚌贝壳中元素分布的初步研究

A preliminary study on elemental profile in the shell of freshwater bivalve Anodonta woodiana

应用电子显微探针元素分析技术,对背角无齿蚌(Anodonta woodiana)的贝壳(棱柱层和珍珠层)进行了19种元素(Ag、Al、Au、Ca、Co、Cu、Fe、Hf、Mg、Mn、Mo、Na、Re、Se、Sn、Sr、Tl、V、Zn)分布特征的初步研究.元素面分布分析和定量线分析结果均直观而明显地表明:贝壳中Ca含量最高,Hf、Re、Mn、Al、Co、Fe、Sr、Cu和Na的含量较低,而Au、Mg、Tl、Zn、Sn、Ag、V、Mo和Se的含量甚少.Mn在珍珠层的分布高于棱柱层,壳顶区域的珍珠层的含量(0.087±0.045)%显著高于棱柱层(0.030±0.025)%(P<0.05),腹缘区域的珍珠层的含量(0.072±0.055)%亦显著高于棱柱层(0.044±0.025)%(P<0.05),而其余元素在贝壳中均匀分布.

An electron probe microanalyzer （EPMA） was used to analyze the content profiles of 19 elements （Ag, A1, Au, Ca, Co, Cu, Fe, Hf, Mg, Mn, Mo, Na, Re, Se, Sn, Sr, T1, V, and Zn） in the shell （prismatic layer and nacreous layer） of freshwater bivalve Anodonta woodiana. Results of both the line transect and map analyses clearly showed that the element contents generally decreased in the order of Ca, Hf, Re, Mn, A1, Co, Fe, Sr, Cu, Na, Au, Mg, T1, Zn, Sn, Ag, V, Mo, and Se Level of Mn in the nacreous layer was evidently higher than that of prismatic layer. Furthermore, Mn content in the nacreous layer of the umbo （0.087±0.045）% was significantly higher than that in the prismatic layer （0.030±0.025）% （P〈0.05）. Likewise, Mn content in the nacreous layer nearby the ventral edge （0.072±0.055）% was significantly higher than that in the prismatic layer （0.044±0.025）% （P〈0.05）. The present study can provide a better basis for selecting a more sensitive bioindicator in our undertaking ＂Freshwater Mussel Watch＂ project.