On this World Earth Day, Singapore's Nanyang Technological University (NTU) researchers have unveiled a new portable device which can instantly detect heavy metals in drinking water in just five minutes with accuracy, making it the best aqua monitor ever invented.
An organic substance called a chelating agent can detect and bind to heavy metal ions and once the compilation process is over, it prevents those elements from interacting with other molecules and enzymes in the human body. But the body can't discharge these metals such as mercury, lead, cadmium (Cd) and Arsenic, which impact later with major long-lasting ill-health.
Associate Professor Yong Ken-Tye and Professor Tjin Swee Chuan from the School of Electrical and Electronic Engineering, combined a chelating agent with an optical measurement system and developed this new technology which can generate test results quickly. Inspired by the human body, this device is convenient for on-site water testing. The scientists claimed that this device can be used along with domestic appliances such as water filters.
The device includes an optical fibre sensor modified with a chelating agent and a laser. This sensor is connected to a processing unit that shows the result of water quality tests.
Usually, the quality of drinking water is checked in laboratories because such heavy metals ions cannot be detected by colour, taste or odour unless present at high levels but the process requires at least a day to generate accurate results.
Even though there are several other devices and tools which can also detect heavy metal contaminants quickly, those commercially available products either take a minimum of 30 minutes to produce the results or fail to meet the standards or needs. On the other hand, the NTU invention requires just a few drops of water sample into a disposable sensor cartridge to perform the same function with more accuracy in just five minutes.
In a news release, NTU said that through this technology the researchers "can detect lead levels of 5 parts per billion, which is lower than the 10 parts per billion limit stipulated by the Environmental Public Health Act in Singapore."
Even the sensitivity of the sensor in the new device is not limited by exposure to air and remains effective up to 40°C temperature.
Prof Yong said that not only the NTU handheld device can conduct quicker tests, but also can detect a maximum 24 types of metal contaminants, which is double the capacity of other commercially available water sensors.
"Using a chelating agent in the device ensures that its sensor is as sensitive in detecting heavy metals as the body's natural defence mechanism against metal intoxication," he further added.
