# Nanomaterials as a Tool for Increasing Sensitivity and Selectivity in the Analytical Chemistry of Tungsten by Stripping Voltammetry

## TL;DR

This paper introduces a sensitive and selective method using nanomaterials to detect trace amounts of tungsten in environmental samples.

## Contribution

A novel hybrid electrode using carbon nanotubes and glassy carbon improves the sensitivity and selectivity of tungsten detection.

## Key findings

- The method achieved a detection limit of 3 × 10−10 mol L−1 for tungsten.
- The electrode showed high reproducibility and resistance to interferences.
- The method was successfully applied to real environmental samples and reference materials.

## Abstract

Tungsten is an extremely durable metal with a wide range of industrial applications and its toxicity is relatively low, although chronic exposure to its compounds can lead to adverse health effects. This paper proposes a method for the determination of trace amounts of tungsten using cathodic stripping voltammetry (CSV). A hybrid structure based on a mixture of multi-walled carbon nanotubes and spherical glassy carbon was used as the working electrode, on the surface of which a film of lead was formed during the measurement to increase the efficiency of the determination. A comprehensive optimization of the analytical parameters, including accumulation potential and time, signal recording conditions and electrolyte solution composition, was carried out to maximize sensitivity and improve the signal-to-noise ratio. The method developed achieved a detection limit for tungsten of 3 × 10−10 mol L−1, demonstrating its high sensitivity. The working electrode showed selectivity, signal reproducibility and resistance to the presence of potential interferences. The reliability and applicability of the proposed solution were confirmed by applying the method to the analysis of real environmental samples and certified reference materials, with satisfactory results. The presented analytical procedure represents a promising tool for the routine determination of tungsten in complex real matrices.