大家好! 我用过液相,通过与标准品的保留时间进行比较,可以知道样品中含有什么物质 NMR法也需要同时做标准品吗,还是有什么数据库能够进行分析呢? 我的样品不是单一的物质,乃是一个反应体系,加入底物,反应一段时间后看是否有产物生成(底物与产物互为同分异构体) 用NMR法验证这个反应的只有3篇文献,只有1篇提到500MHz的条件,其余2篇没有说,不知道这种情况我能重复吗?3篇文献的结果我也没有找到相同的数据(ppm) 文献1: The products of the isomerization were determined by 1H NMR spectroscopy. The conversion of IPP to DMAPP was con?rmed by the appearance of peaks at 5.45 (H at C-2), 1.77 (E-methyl group), and 1.72 ppm (Z-methyl group) for IPP and a corresponding reduction in the intensity of peaks at 2.40 (H at C-2) and 1.78 ppm (methyl group) (35). Peaks for the protons at C-1 of both diphosphates and the C-4 ole?nic protons in IPP were obscured. 文献2: