Studies on the Element Characteristics of Nephrite Minerals from Different Deposits by GD-MS

Abstract

Element characteristics of nephrite minerals were determined by glow discharge mass spectrometry (GD-MS) through surface adherence method. To solve the conductivity problem of non-conductive nephrite samples, high purity indium pin (＞99.9999%) was used as discharge host. During the preparation procedure, a small piece of nephrite sample was ground into powder (about 200 meshes), and then the sample powder was coated on the surface of indium pin to form a rod sample. Typical elements of nephrite minerals were analyzed by GD-MS, and the relative standard deviations showed that the stability and reproducibility of this method were good. Meanwhile, four nephrite samples from two different deposits were further studied by this method. The GD-MS results of major elements and trace elements revealed that typical elements of the nephrite minerals from same deposit were similar, and those from different deposits exhibited significant difference. In addition, results of external-beam proton induced X-ray emission (PIXE) were consistent with the result of GD-MS determination. The present approach had been proven to be simple, efficient to perform the rapid screening and multi-element semi-quantitative analysis of nephrite samples.

Studies of rare earth elements to distinguish nephrite samples from different deposits using direct current glow discharge mass spectrometry

“…The combination of discharge gas, discharging host and matrix of samples might contribute some interference. In our previous study, 37 because of the use of indium, the matrix elements of nephrite, such as Si, Mg, and Ca, and the discharge gas Ar caused some interference, such as of 115 In 24 Mg with 139 La, 115 In 25 Mg with 140 Ce, 115 In 36 Ar with 151 Eu, 115 In 40 Ar with 155 Gd, and so on. These interferences were mainly in the REE region and made it hard to determine the rare earth elements in nephrite.…”