DEVELOPMENT AND VERIFICATION OF YTTRIUM, GADOLINIUM, AND ERBIUM ANALYSIS METHOD FROM GEOLOGICAL SAMPLES USING ICP-OES

• Main Author: Yolanda
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/79206
• Institution: Institut Teknologi Bandung

The characteristics of Rare Earth Elements (REE), both Light Rare Earth Elements (LREE) and Heavy Rare Earth Elements (HREE), can be utilized to produce advanced technological materials in various fields. The exploration, processing, and utilization of primary REE resources in Indonesia from geological sources is one of the potentials that can be maximized. Chemical Laboratory of The Coal and Geothermal Mineral Resources Center (PSDMBP) also plays a role by analyzing geological samples obtained from field exploration. It is necessary to develop and verify methods to support the analysis process using instrument with high sensitivity such as Inductively Coupled Plasma – Optical Emission Spectrometry (ICP-OES). This study focuses on determining an effective method for the digestion of geological samples for the analysis of Yttrium (Y), Gadolinium (Gd), and Erbium (Er), which are classified as HREE, using ICP-OES. The chosen digestion method is then verified with several parameters such as accuracy, precision, linearity, sensitivity, Limit of Detection (LOD), and Limit of Quantification (LOQ). Of the three digestion methods that have been used, the elements Y, Gd, and Er in rock-type geological samples can be analyzed using ICP-OES by digesting them with a combination of HF, HClO4, and HNO3. The accuracy values of the method for the CRM REE-1 and GRE-03 fell within the acceptable range of 80-110% with %RSD < 2/3 CV Horwitz which indicates good precision except for Gd on CRM REE-1. However, this digestion method did not yield satisfactory accuration for sedimentary rock samples (NCS DC 73307). The linearity for these three elements was good with R2 values greater than 0.995. The sensitivities for Y, Gd, and Er were found to be 5018.2, 1415.5, dan 3774.4, respectively. The LOD values for Y, Gd, and Er were 0.02 ppm, 0.04 ppm, and 0.02 ppm, respectively with the LOQ values were 0.05 ppm, 0.10 ppm, and 0.05 ppm, respectively. The method was applied to analyze four geological samples obtained from PSDMBP field exploration, resulting in Y concentrations ranging from 2.94 ppm – 5.00 ppm, Gd concentrations ranging from 3.33 ppm – 9.72 ppm, and Er concentrations ranging from 1.77 ppm – 2.06 ppm.