Development of a Tellurium Speciation Study Using IC-ICP-MS on Soil Samples Taken from an Area Associated with the Storage, Processing, and Recovery of Electrowaste.

Katarzyna Grygoyć,Magdalena Jabłońska-Czapla

doi:10.3390/molecules26092651

Abstract

The optimization and validation of a methodology for determining and extracting inorganic ionic Te(VI) and Te(IV) forms in easily-leached fractions of soil by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry (IC-ICP-MS) were studied. In this paper, the total concentration of Te, pH, and red-ox potential were determined. Ions were successfully separated in 4 min on a Hamilton PRPX100 column with 0.002 mg/kg and 0.004 mg/kg limits of detection for Te(VI) and Te(IV), respectively. Soil samples were collected from areas subjected to the influence of an electrowaste processing and sorting plant. Sequential chemical extraction of soils showed that tellurium was bound mainly with sulphides, organic matter, and silicates. Optimization of soil extraction allowed 20% average extraction efficiency to be obtained, using 100 mM citric acid as the extractant. In the tested soil samples, both tellurium species were present. In most cases, the soils contained a reduced Te form, or the concentrations of both species were similar.

Highlights

Global trade networks of goods, in which materials move along the value chain of mining, processing, manufacture, use, disposal, collection, and waste management, have increased in complexity in recent years as multiple countries are involved in the life-cycles of products [1]
One of the Less Studied Technology Critical Element (LSTCE) is tellurium, which is increasingly employed in optical magnetic discs, solar panels, and Peltier device production [2]
Its chemical behavior is similar to selenium and in the natural environment can exist in several redox states: telluride (−II), elemental tellurium (0), tellurite (IV) and tellurate (VI) both in organic and inorganic forms

Summary

Introduction

Global trade networks of goods, in which materials move along the value chain of mining, processing, manufacture, use, disposal, collection, and waste management, have increased in complexity in recent years as multiple countries are involved in the life-cycles of products [1]. As a consequence of the growing use of electronic and industrial products, increasing amounts of TCE (Technology Critical Elements) are being released to the environment. One of the Less Studied Technology Critical Element (LSTCE) is tellurium, which is increasingly employed in optical magnetic discs, solar panels, and Peltier device production [2]. Te(IV)/Te(VI) ratio can differ under different environmental and biological conditions but studies in natural systems are lacking due to extremely low Te concentrations in geological, environmental, and biological samples and most of them is focused on developing the research methodology and rather concerns the total content of tellurium. Ferri et al [7] studied tellurium species concentration in Soil NIST SRM 2709 (National Institute of Standards and Technology, Standard Reference Material) and showed that in this material the content of inorganic tellurium species was 50% Te(VI) and Te(IV). Under oxic conditions Te was mainly associated with iron (III) hydroxides, and Te(IV) and Te(VI) species were both found to inner-sphere complexes

Methods

Results

Conclusion