The analytical methodology of isomers quantification has been studied and published in former study (Wang et al., 2013). From Figure1 in Supporting Information, it seems that the isomers were not separated, but actually it does not affect the quantification of the isomers. Because the main quantitative ions were used for quantification and the main quantitative ion of each isomer were separated absolutely (Figure 1). Table 1 and Figure 1 were cited from Wang et al (2013). Moreover, series of research about the NP isomers were conducted and published afterwards. The following are the publications.
Shiyu Wang, Wenyong Wu*, Fei Liu, Shiyang Yin, Zhe Bao, Honglu Liu.