Panax notoginsengis an important functional health product, and has been used worldwide because of a wide range of pharmacological activities, of which the taproot is the main edible or medicinal part. However, the technologies for origin discrimination still need to be further studied. In this study, an ICP-MS/MS method for the accurate determination of 49 elements was established, whereby the instrumental detection limits (LODs) were between 0.0003 and 7.716 mg/kg, whereas the quantification limits (LOQs) were between 0.0011 and 25.7202 mg/kg, recovery of the method was in the range of 85.82% to 104.98%, and the relative standard deviations (RSDs) were lower than 10%. Based on the content of multi-element inP. notoginseng(total of 89 mixed samples), the discriminant models of origins and cultivation models were accurately determined by the neural networks (prediction accuracy was 0.9259 and area under ROC curve was 0.9750) and the support vector machine algorithm (both 1.0000), respectively. The discriminant models established in this study could be used to support transparency and traceability of supply chains ofP. notoginsengand thus avoid the fraud of geographic identification.Keywords:Panax notoginseng;ICP-MS/MS;multi-element;origin discrimination;cultivation model discrimination
Jisheng Chen,Youyi Ni,Wenting Bu,Yue Luo,Bingjun Chen,Xuemei Liu,Chuting Yang,Junwen Wu,Hai Wang
Highly efficient and accurate analysis of ultra-trace anthropogenic 236 U in the presence of natural uranium isotopes is essential for nuclear forensics and environmental monitoring. In this study, we developed an integrated analytical method for the determination of 234 U, 235 U, 236 U, and 238 U by combining highly automated sample preparation with highly sensitive ICP-MS/MS detection. Automated total dissolution was employed to ensure complete extraction of both endogenous and exogenous uranium from solid matrices, while reproducible chemical separation was achieved using an automated platform equipped with regenerable UTEVA resin. This optimized procedure yielded exceptionally low operational blanks for 236 U at femtogram level. Moreover, the final eluent volume was minimized to 1.5 mL, allowing direct introduction into the ICP-MS/MS. By utilizing a membrane desolvation sample introduction system and a novel mass-shift mode (targeting UO 2 + species), the ICP-MS/MS sensitivity exceeded 4.1×10 6 cps/ppb, while the 235 UH + interference formation rate for 236 U was suppressed to 7.1×10 -10 . Consequently, the achieved detection limits for 236 U and the 236 U/ 238 U atom ratio were as low as 1.85 fg/g and 5×10 -12 , respectively. This method was successfully applied to determine the uranium isotopic composition in sediments from the adjacent sea area of the Daya Bay Nuclear Power Plant. These results demonstrate that the proposed method provides a robust and high-throughput solution for accurately quantifying of ultra-trace 236 U in environmental samples, such as those impacted by the global fallout.
危险品化学品经营许可证（带存储）