X射线荧光光谱法测定硫酸镁及其水合物中镁、硫元素含量

Determination of Magnesium and Sulfur in Magnesium Sulfate and Its Hydrates by X-ray Fluorescence Spectrometry

为提高测定效率,开展了X射线荧光光谱法测定硫酸镁及其水合物中镁、硫含量的试验研究。将硫酸镁及其水合物样品在(450±25)℃灼烧至恒重,然后采用粉末压片法制样,对镁、硫元素含量进行灼烧减量校正,并根据校准后镁、硫元素含量与X射线荧光强度的关系绘制校准曲线,建立了测定硫酸镁及其水合物样品中镁、硫元素含量的X射线荧光光谱法。灼烧试验结果表明:硫酸镁及其水合物样品在(450±25)℃灼烧2.0 h后可完全脱除结晶水,且不会造成硫元素的损失;校准曲线的相关系数均大于0.999。精密度试验结果表明,测定值的相对标准偏差(n=8)为0.39%~0.42%。分别采用X射线荧光光谱法和化学法测定待测样品,得到的测定结果相吻合。采用X射线荧光光谱法测定硫酸镁及其水合物中镁、硫含量,解决了硫酸镁及其水合物校准样品难以直接采用粉末压片法制样的难题,方法的精密度和准确度均满足测定要求。

In order to improve the determination efficiency,an experimental study on the determination of the content of magnesium and sulfur in magnesium sulfate and its hydrates by X-ray fluorescence spectrometry(XRF)is carried out.The magnesium sulfate and its hydrate samples are burned to constant mass at(450±25)℃,and then the samples are prepared by powder compression method,and the ignition loss correction is performed on the content of magnesium and sulfur.The relationship between the content of magnesium and sulfur and the X-ray fluorescence intensity is used to draw a calibration curve,and a method is established to determine the content of magnesium and sulfur in magnesium sulfate and its hydrate samples by XRF.The ignition test results show that the magnesium sulfate and its hydrate samples can completely remove the crystal water after burning at(450±25)℃for 2.0 h without causing the loss of sulfur;the correlation coefficients of the calibration curve is greater than 0.999.The precision test results show that the relative standard deviation(n=8)is 0.39%to 0.42%.The XRF and the chemical method are used to determine the sample to be tested,and the results obtained are consistent.XRF is used to determine the content of magnesium and sulfur in magnesium sulfate and its hydrates,which solves the problem that magnesium sulfate and its hydrate calibration samples cannot be directly prepared by powder compression method.The precision and accuracy of the method meet the determination requirements.