Rapid Analysis Of Aurantii Fructus Immaturus (Zhishi) Using Ambient Ionization Mass Spectrometry

Paperspray Mass Spectrometry(PS-MS)reported 8 years ago is a kind of Ambient ionization mass spectrometry(AMS).PS-MS is a rapid,solvent-efficient,and high-throughput analytical method for analyzing complex samples,which has several advantages,such as simple sample preparation,sample loading,analyte extraction.Aurantii Fructus Immaturus(aka Zhishi in Chinese),a traditional Chinese herb listed in the Chinese Pharmacopoeia。In this work,three tasks were carried out and the results are as follows: 1.The HPLC fingerprints of Zhishi were obtained by HPLC,and the seven chemical constituents of Zhishi were confirmed by LC-MS/MS.Moreover,in combination with multivariate analyses,including principal component analysis(PCA)and cluster analysis(HCA)the HPLC fingerprints of 25 batches of Zhishi were discriminated in 25 batches of Qingpi(an adulterant of Zhishi).They are clustered in two relatively discrete groups.The PC1 and PC2 scores were high(92.20% and 3.99%,respectively).HCA showed that the 25 batches of Zhishi and 25 batches of Qingpi were classified into two categories,which proved that the identification of species could be achieved by HPLC.2.A PS-MS method was developed to obtain MS profiles of Zhishi in positive and negative ion modes.In combination with PCA and HCA,the PS-MS profiles of 25 batches of Zhishi were discriminated in 25 batches of Qingpi.The PC1 and PC2 scores were relatively low(68.87% and 7.27%,respectively).The Zhishi samples did not cluster tightly.However,the two groups can be clearly distinguished from each other.The data points of the samples are located in the same region as the data points of their corresponding standard materials,The same result was obtained by HCA.Therefore,PCA and HCA of PS-MS data is suitable for the categorization of Zhishi and Qingpi,PS-MS method is far faster than HPLC method.3.A rapid quantitative analysis of synephrine,a prescriptive quality control component of Zhishi,was conducted with PS-MS using synephrine-d2 as an internal standard(IS),which was lab-made.The linearity range was 1.68–16.8 mg/mL(R2=0.9985),the limit of quantitation was 0.5 mg/mL.Relative standard deviations in the intra-and inter-day precision of the MS were 4.87 and 4.90%,respectively.Compared with HPLC results,there was no significant difference in the quantitation of synephrine.This study demonstrated that the PS-MS method is useful for the rapid discrimination and quality control of Zhishi samples,which gives ideas for quality control of other traditional Chinese medicine.