Mg,Ca,Sr,Ba同为碱土金属,性质相似,准确分析SrCO3产品中的Sr,Ca,Mg,Ba难度大,分析繁杂。文章采用人工合成配制系列标准样,以硼酸镶边垫底的粉末压片法制样,建立了准确分析SrCO3产品中主次组分的定量分析曲线,可同时测量SrCOa产品中的Sr,Ba,Ca,Mg,Si,Fe,Al,S等组分。由于SrCO3产品中Sr含量高,按照仪器给定的测量条件进行测量产生谱峰饱和现象,造成计数率溢出,分析误差较大,文章对Sr的分析条件进行了分析,提出通过降低Sr的测定功率来降低计数率,达到测量目的;粉末压片制样分析SO4时,随着测量次数的增加,SO4^2-的结果呈递增趋势,在文中提出了解决方法;同时对自成特性很差的SrCO3产品的压片条件进行了讨论。使用α经验系数法校正基体效应,经对配制的合成样进行检验,测量值与标准值结果吻合。方法的检出限和准确度满足分析要求,除SO4^2-的RSD〈9.0%,其他主次元素RSD〈2.5%。
In the present paper a method for the determination of strontium, barium, calcium, magnesium, silicon, iron, aluminum and sulfur in the product of strontium carbonate by X-ray fluorescence spectrometry with pressed powder sample preparation was developed, and the standard samples were synthesized by high purity reagent. As the contents of strontium in the product of strontium carbonate were very high, the phenomenon of spectrum-peak-saturated occurred and the count rate was overflowed according to the measuring condition which was automatically given by the software system of X-ray fluorescence spectrometry. As a result, the deviation of the measurement is greater. According to analyzing the measuring condition of strontium, a method was given for reducing the count rate by reducing the measuring power of strontium, thus achieving the goal of measurement. When sulfate was measured with pressed powder sample, the results were enhanced with the increase in measuring number. In light of this situation, a method was proposed to solve the problem. As the self-forming characteristic of the product of stronti- um carbonate was not so well, it was very difficult to press the sample successfully. So, the condition of squash method involving the kinds of the adhesives, the mixing technique with powder sample and the pressing-time technique was discussed. During making the sample, it was found that the effects of pellet formation were better if the time could be delayed by 120 seconds. Matrix effect was corrected by alpha coefficient method, the accuracy of the method was evaluated by analysis of synthetic sample. Detection limits of 0. 623-107.6 mg . g^-1 were obtained. The results were in good agreement with certified values with precision of 〈2.5% RSD.