Study On The Law And Correction Method Of Double-charged Ion Interference In Mineral In-situ Micro-analysis

Laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS)is an in-situ micro-analysis technique that is an important tool for sample analysis in the geological field.It can quickly and accurately quantify trace elements in a variety of mineral ores.However,in the current progress of mass spectrometry technology optimization,the international focus will be on mass spectrometry interference and nonmass spectrometry interference,taking some professional ratios,precision analysis and other means,while domestic research mainly involves general applications and online applications.There are many shortcomings in such technologies.Mass spectrometry interference(homologous interference,polyatomic ion interference,double-charged ion interference)is an important factor affecting the accuracy of quantitative mass spectrometry results.At present,the research on mass spectrometry interference in the whole field in the world still needs to be increased,especially in the case of doublecharged ion interference.This research relies on the basic research business project “Study on the composition and structure analysis technology of mineral micro-regions of typical rare earth-sparse deposits”.The system summarizes the sources,existing problems and current processing methods of various types of mass spectrometry interference,and focuses on the elements that may be affected by the double-charged ions(M++/M+)during mass spectrometry./isotope.Through the analysis of different matrix standards,the formation characteristics of double-charged ions in the process of laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS)were studied,and the degree of double-charged ion interference was evaluated,and the LA-ICP-MS analysis was proposed.Charge ion interference correction scheme.According to the experimental results,the conclusions of the regularity scientific findings are as follows:1.Under the same analysis conditions,the LA-ICP-MS analysis of different matrix samples found that the element double-charged ion yield was higher(M++/M+,0.02-3.56%),among which The double ionization of rare earth elements(REE)is most obvious.2.The double-charged ion yield of the element decreases with the decrease of atomic radius and the increase of the second ionization energy of the element,and exhibits a good and stable logarithmic relationship.3.The same element is different.The isotope's double-charged ion yield is consistent.Therefore,in the LA-ICP-MS analysis process,the high-double charge interference risk element/isotope can be monitored to interfere with the odd-mass double-charged ion yield of the parent element or to monitor the double charge of several elements/isotopes with similar double ionization energy.Ion yield,the doubly charged ion yield of the element/isotope was obtained by fitting interpolation and the interference was subtracted.The calibration method is used to perform interference subtraction(for example,Ba++,La++ on Ga interference)on the LA-ICP-MS analysis results of the internal carbonate standard sample(high REE content)in the laboratory,and the results(numerical values)and standard values(values)are obtained.Consistent within the error range.