A portable device for measuring lead pollution

American researchers have created a miniature device that can detect lead pollution in sediment layers in a few minutes. A quick method that would eliminate the need for laboratory tests.

Lead is one of the heavy metals most commonly found in the environment and in particular at the bottom of rivers. Currently, the detection of heavy metal pollution requires collecting samples by boat and sending it to an analysis laboratory, which takes several days.

A portable graphene-based detector

The detection of lead currently requires the use of heavy characterization techniques such as atomic absorption spectroscopy or inductively coupled plasma mass spectrometry (ICP-MS). These methods are not field techniques and they are neither fast nor economical.

The team of researchers from the American University of Rutgers (State University of New Jersey) therefore worked on the development of an electrochemical detection method based on voltammetry. According to the study published in the journal “IEEE Sensors”, the operation of this new lead detector is based on the use of the electrochemical properties of graphene oxide.

This detector was thus developed , calibrated, tested and its performance analyzed. The results seem promising, as the sensitivity of the detector is quite good:

  • 73 µA ppb-1 cm-2 over the range 0-100 ppb;
  • 9 µA ppb-1 cm-2 over the 100 ppb-20 ppm range;
  • detection limit of 4 ppb.

This detector is thus able to quantify small quantities of heavy metals in sediments .

A very wide field of application

The sediments of many American rivers are contaminated by industrial wastes dumped decades ago. The management of dredged material from navigation canals therefore requires rapid identification of contaminated areas, in order to limit the impact on ecosystems and agriculture. This new measurement technique could therefore make it possible to carry out economical and efficient management programs.

The next work should focus on miniaturization, in order to create a portable instrument capable of giving the pollution rate simultaneously from collection of sediment.

In addition, beyond the detection of lead in sediments, this method could be used to analyze the level of heavy metals present in drinking water, or even in food.

Mehdi Javanmard, associate professor in the Department of Electrical and Computer Engineering, explains: “With a tool like this, one day you could go to a sushi bar and check if the fish you you ordered contains lead or mercury. ”

Based on Todd Bates August 26, 2020 article for Rutgers