Analysis of 23 Elements in Liuwei Dihuang Pills by Inductively Coupled Plasma Mass Spectrometry with Chemometrics

A method for the simultaneous determination of 23 elements, including Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Cd, Cs, Ba, Tl and Pb in Liuwei Dihuang pills by inductively coupled plasma mass spectrometry (ICP-MS) was proposed, and the content of each element was analyzed with chemometrics. According to guideline for elemental impurities issued by International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use, health risks of 8 harmful elements including Cd, Pb, As, Co, V, Ni, Cu and Cr were evaluated. The Liuwei Dihuang pills were digested by microwave, and ²³Na, ²⁴Mg, ²⁷Al, ³⁹K, ⁴⁰Ca, ⁵¹V, ⁵²Cr, ⁵⁵Mn and ⁵⁶Fe were determined by using ⁴⁵Sc as internal standard with collision pool mode, ⁵⁹Co, ⁵⁹Ni, ⁶⁴Cu, ⁶⁶Zn, ⁷⁰Ga, ⁷⁵As, ⁷⁹Se, ⁸⁵Rb and ⁸⁸Sr by using ⁷³Ge as internal standard, ¹¹²Cd, ¹³³Cs and ¹³⁷Ba by using ¹¹⁵In as internal standard, ²⁰⁵Tl and ²⁰⁷Pb by using ²⁰⁹Bi as internal standard. It was shown that the linear relationships between the mass concentrations of 23 elements and the ratios of corresponding response values of each element to internal standard in definite ranges, with detection limits (3s/k) in the range of 0.000 9-4.807 μg·L^-1. Test for recovery was made by standard addition method, giving results in the range of 84.9%-112%. The fingerprints of elements of Liuwei Dihuang pills were established according to the determination results of 21 batches of samples, and SPSS 20.0 software was used for principal component analysis and cluster analysis, and the health risk assessment of harmful elements was conducted. The results showed that the contents of 23 elements in Liuwei Dihuang pills had certain regularity, and the fingerprints could be used to identify Liuwei Dihuang pills. Four principal components were obtained by principal component analysis, and the cumulative variance contribution rate was 81.579%, and V, Co, Cs, Fe, Tl, Ga, Ba, Mg, Sr, Na, Se and Cd were selected as the characteristic elements of Liuwei Dihuang pills. The 21 batches of samples were divided into 3 categories by cluster analysis, and the contents of elements in most samples were similar. The health risk assessment showed that the content of Pb in one batch of sample presented a health risk, while the health risk of harmful elements in the remaining batch of samples was within the acceptable range.