Determination of Trace Elements in Cistanches Herba from Different Habitats by ICP-MS
OBJECTIVE To establish a method for the determination of 37 kinds of inorganic elements by microwave digestion and inductively coupled plasma mass spectrometer(ICP-MS),and to detect and analyze 37 kinds of inorganic elements in cistanches herba from different habitats,and to preliminatively explore the pollution distribution of various inorganic elements in cistanches herba from different habitats.METHODS Using nitric acid and hydrogen peroxide as digestion reagent,microwave digestion was used to pretreat the samples.The contents of 37 inorganic elements in cistanches herba were determined simultaneously by internal standard correction and external standard quantitative ICP-MS method.RESULTS In the curve range of 0.50-100 μg·L-1(Hg:0.20-20 μg·L-1)showed a good linear relationship with the peak area(r≥0.997 4).The detection limits were 0.000 27-0.045μg·L-1.The average recoveries were 76.5%to 110.0%at high,medium and low levels.RSD of precision and repeatability were lower than 4.8%.The detection rates of 5 harmful heavy metal elements(copper,lead,arsenic,mercury,cadmium)that need to be controlled by Chinese Pharmacopoeia(2015 edition)in 40 batches of cistanches herba were 27.5%,7.5%,82.5%,0 and 100%,respectively.The detection rate of barium,manganese,rubidium and strontium in 40 batches of samples is 100%,and the content is much higher than other elements,there are obvious regional differences.CONCLUSION This method has high sensitivity,good reproducibility,reduced the inspection time and cost,and can simultaneously detect various inorganic elements in cistanches herba,providing data support for optimal cultivation,quality assurance and drug safety of cistanches herba.