METHOD FOR SELECTING REFERENCE SAMPLES FOR EXTERNAL STANDARDIZATION IN LA-ICP-MS ANALYSIS OF U-Pb AND Lu-Hf ISOTOPIC COMPOSITION OF ZIRCON MINERAL Russian patent published in 2023 - IPC G01N21/62 G01N23/2254 

FIELD: analytical atomic spectrometry.

SUBSTANCE: method for selecting reference samples for external standardization in the analysis of the U-Pb and Lu-Hf isotopic composition of the zircon mineral using laser ablation and inductively coupled plasma mass spectrometry. When implementing the method, cathodoluminescence spectra are obtained with a locality of about 1 mcm from the studied zircon grain and certified reference samples in the range of 1.5–6.0 eV. Next, the areas of the bands A_i, B_i, С_i with maxima in the region of 4.3–5.0, 2.6-3.5, 2.1–2.3 eV are calculated and a calibration triple diagram А_i-В_i-С_i is built. As a reference sample, a sample is chosen that is closest on the triple diagram to the studied grain, and it is used for subsequent correction of elemental fractionation in the mass spectrometric analysis of the isotopic composition of zircon.

EFFECT: simplifying the method and increasing the accuracy of choosing a comparison sample.

1 cl, 4 dwg, 1 tbl