Preparation And Characterization Of Element-doped Glass Reference Materials

Laser Ablation Inductively Coupled Plasma Mass Spectrometry（Laser AblationInductively Coupled Plasma Mass Spectrometry,LA-ICP-MS）is a technique for in-situ microanalysis of solid samples.It has the advantage of simple sample preparation,low sample consumption,multi-element analysis and simultaneous multi-element analysis,which can be used to characterize the element content and element distribution in the samples.However,the analytical accuracy of LA-ICP-MS is often affected by factors such as instrument conditions,fractionation effects and matrix effects.Among them,reference materials are often used for matrix matching and play an important role in the accuracy of quantitative results.The silicate glass reference materials as a kind of reference material,which are often used in the analysis of geological samples and silicate samples.At present,the commonly used silicate glass reference materials are the American NIST series of glass standard materials,which have problems such as high prices.In addition,there are few domestic studies on silicate glass reference materials.Whether the uniformity and accuracy of the silicate glass reference materials meet the requirements depends on the preparation process and performance characterization method.Therefore,it is of great significance to carry out researches on the synthesis of domestic silicate glass reference materials and the establishment of appropriate calibration strategies to prepare reference materials that can be used for LA-ICP-MS in-situ microanalysis.In this work,the high-temperature melting method was used to prepare the silicate glassreference materials and its process was optimized.Inductively Coupled Plasma Atomic Emission Spectrometer（ICP-OES）and Inductively Coupled Plasma Mass Spectrometer（ICP-MS）were used to quantitatively analyze the content of elements in the glasses.By optimizing the parameters of LA-ICP-MS to reduce the influence of fractionation effect,and at the same time determining the appropriate calibration strategy,it can realize the characterization of the element distribution in the glasses.Finally,the prepared silicate glasses were used for the actual sample detection by the combination of internal and external standards.The main results are as follows:（1）By optimizing the composition and process parameters,the silicate glasses wereprepared by the high-temperature melting method,and the influence of the number of melting and the doping method on the uniformity of the element distribution in the glass and the accuracy of the doping concentration were explored.The glass composition was finally determined,and the process parameters are as follows:melting at 1500℃for 2 h,fusing twice,choosing solid powder doping method,and annealing at 520℃for 4 h.（2）The parameters of LA-ICP-MS were optimized,when the laser energy density was8.24 J/cm²,the laser pulse frequency was 20 Hz,the laser ablation aperture was 70μm,the laser scanning rate was 30μm/s,and the He gas flow rate was 800 m L/min,the sampling depth was 150mm,the RF power was 1350 W and the Ar gas flow rate was 700 m L/min,the obtained element signal intensity as well as stability was the best.Based on the above optimized parameters and the determined experimental scheme,LA-ICP-MS was used to characterize the uniformity of the prepared silicate glasses.The results showed that the uniformity of the elements distribution in the prepared glasses were good.ICP-OES and ICP-MS were used to quantitatively analyze the content of doped elements in silicate glasses after digestion,and they were used as reference materials to establish a standard curve at the same time.The results showed that apart from B,K,Co,Se elements and the low content doped elements,the content of other elements in the remaining glasses was consistent with the theoretical value.The established standard curves had good linearity,and the linear correlation coefficient（R²）was greater than 0.99.（3）²⁹Si was selected as an internal standard element,the combination of internal andexternal standards was used to correct the matrix effect and the sensitivity drift caused by the instrument analysis process.The prepared silicate glass reference materials were used as the reference material to perform quantitative analysis on the commercial reference samples of NIST610 and NIST 612 in the United States and the domestic ordinary silicate glass samples.The results showed that for the NIST 610 and NIST 612,the LA-ICP-MS quantitative results were consistent with the reference values of NIST 610 and NIST 612.For the detection of domestic silicate glass samples,the LA-ICP-MS quantitative values were consistent with the ICP-MS quantitative values.Therefore,this showed that the glass samples prepared in this work are reliable as reference materials and can be used for actual sample detection.