Study on total contents of 20 trace elements in Niuhuang Jiedu tablets and their extract rates in water and gastrointestinal fluids by ICP-MS

Objective: To investigate total contents of 20 trace elements in Niuhuang Jiedu tablets and their extract rates in water and gastrointestinal fluids by inductively coupled plasma mass spectrometry( ICP- MS). Methods:An ICP- MS method for simultaneous determination of 20 trace elements was established,and the contents of these20 trace elements in Niuhuang Jiedu tablets and their extract rates in water,artificial gastric fluid and artificial intestinal fluid were determined,compared and analyzed. Results: The method validation indicated that the correlative coefficients( r) for all elements were over 0. 9990; the precisions,stabilities and recoveries for all elements in both Niuhuang Jiedu tablets and extracting solutions met the determination requirements; the determined values of NIST tomato leaves( SRM 1573a) were in accordance with those certified. The results of sample analysis showed that insufficient realgar was formulated in some Niuhuang Jiedu tablets; almost the same extract rates for arsenic were found in water and in gastrointestinal fluids,while higher extract rates for other 19 elements were found in gastrointestinal fluids than that in water; the extract rates for arsenic were low( 0. 805%- 1. 926%); however,the amount extracted in gastrointestinal fluids was still large due to the extreme high arsenic contents in Niuhuang Jiedu tablets;the contents of mercury in some Niuhuang Jiedu tablets were also found over regulation defined limit; however,only very few and constant mercury was extracted in gastrointestinal fluids. Conclusion: The dissolved aresenic species of Niuhuang Jiedu tablets should be further researched.