Determination Of Inorganic Elements In Diaphragma Juglandis Fructus And Its Water-extraction Based On Microwave Digestion-Inductively Coupled Plasma Mass Spectrometry

Objective: Diaphragma Juglandis Fructus is used in traditional Chinese medicine（TCM）to treat infertility,but there is no relevant scientific evidence to confirm its effects.However,Inorganic elements play a significant role in the human body.Because of lacking in both a fast-stable inorganic elements analysis method for Diaphragma Juglandis Fructus and research on the composition of inorganic elements and effective organic ingredients in them.1.Aim to establishing a set of accurate,fast and stable microwave digestion-inductively coupled plasma mass spectrometry（ICP-MS）method to determine the content of each element in the Diaphragma Juglandis Fructus and its water-extraction in this study with analysis objects of 16 inorganic elements.2.In order to analyze the differences of the content of 16 inorganic elements in Diaphragma Juglandis Fructus and its water-extraction between Kashi in Xinjiang Province and Yangbi in Yun Nan Province.it is the foundation to build an Ultrasonic water extraction method for analyzing inorganic elements in water-extraction of Diaphragma Juglandis Fructus.Methods: 1.The methed coupled with the advantages of wet digestion and microwave digestionand it was optimizedby HNO₃ and H₂O₂ mixed system in the sample pretreatment process.In the experiment,Octople Reaction System was used to eliminate the mass spectrum interference.Non-mass interference was optimized By matching the acid concentration between the standard solution and sample solution and using the method of internal standard element.The sensitivity,accuracy and stability of the method were confirmed by repeated experiments and standard material.2.Taking element Fe,Cu,Mn,Zn,Sr and the weight of freeze-dried powder of water-extraction as indexes,three factors three levels of orthogonal experiment wastaken to optimize the conditions for ultrasonic water extraction.3.Using SPSS 19.0 and SIMCA 13.0 for statistical analysis,data was analyzed by the cluster analysis and paired T test and principal component analysis and Partial least squares discriminant analysis.Results: 1.In this study,4 mL HNO₃ and 2 mL H₂O₂ were finally selected as the digestion solution,in which H₂O₂ was added in two steps.The standard curve of 16 kinds of inorganic elements all had a good linearity,and their r values were all above 0.999.The standard substance repeatability of shrub branches and leaves was between 86.25% and 110.25%,andrepeatabiliy of Diaphragma Juglandis Fructus was between 84.00% and 105.31%.The average content of elements Mn,B,Fe,Ba,Sr,Al were31.9,19.0,19.1,15.9,13.4,10.5 mg/kg,Cu and Zn were 5.0 mg/kg and 3.6mg/kg,V,Cr,Ni,Mo,As,Cd,TI,Pb were all lower than 0.4 mg/kg in Diaphragma Juglandis Fructusin Yangbi.2.The condition of the water extraction method is that the ratio of solid-liquid is 1:30,and the sample was treated with ultrasound for 15 minutes in a water bath at 60 ℃ to 70 ℃,and then repeated all these steps again.The average content of elements B,Cu,Zn,Fe,Mn,Ba,Sr,Al were 36.1,28.8,21.3,22.6,29.6,7.3,8.7,13.5 mg/kg,and Ni was 2.0 mg/kg.The average content of V,Cr,Mo,As,Cd,TI and Pb were all lower than 0.5 mg/kg in water extraction of Diaphragma Juglandis Fructusin Yangbi.Conclusion: In this study,an accurate,rapid and stable method based on microwave digestion inductively coupled plasma mass spectrometry（ICP-MS）was established for the analysis of 16 inorganic elements in Diaphragma Juglandis Fructus and its water-extraction.The results show that the analysis efficiency of this method was significantly improved compared with the national standard method GB5009.268-2016.There are differences in the distribution of elements in Diaphragma Juglandis Fructus between Yangbiand Xinjiang.According to the experimental results and collecting data from government agencies concluded that differences come from soil conditionand air quality.The element distribution in the water extract was affected by ultrasonic time,solid-liquid ratio and extraction times,but the trend of each element was different.The results also show that there is no food safety risks in Diaphragma Juglandis Fructus.The content of heavy metal elements in it is very low,which conform to the requirements of national standards.