含典型氟-氢邻近与远程耦合的混合物的核磁共振氢谱示例

Two serials of tetrasubstituted benzene compounds containing fluoro group were designed and synthesized. The other three substitutes are sequentially the para, meta, and ortho to fluoro group. The obtained compounds were all mixtures as confirmed by ¹H NMR spectroscopies. The spectra clearly show the proximity and remote interaction between fluorine atom and hydrogen atom. In addition, the two spectra, one showing the overlapping peaks, one not, can be used as the simple and typical example of ¹H NMR spectra of mixtures.     

微波消解-氢化物原子荧光光谱法测定农产品中铅

建立了微波消解-氢化物原子荧光光谱法测定农产品中铅含量的分析方法,对仪器条件和反应条件进行了选择、优化。方法的检出限为0.80μg.L-1,相对标准偏差小于10%,回收率为94.0%~113.5%。该方法具有试剂用量少、检测快速、基体干扰小、准确度高等优点,符合农产品中痕量元素的分析要求。