Researchers have developed a three-dimensional (3D) paper-based portable device that can detect adulteration in milk within 30 seconds.
The test, which could be performed at home, can detect multiple commonly-used adulterating agents including urea, detergents, soap, starch, hydrogen peroxide, sodium-hydrogen-carbonate and salt, among others, they said.
Requiring only a millilitre of a liquid as a sample for the test, the researchers said that the test can be used to detect adulteration in other liquids as well such as water, fresh juices and milkshakes.
The research, led by Indian Institute of Technology (IIT) Madras, is published in the journal Nature. "The 3D paper-based microfluidic device is made up of a top and bottom cover and a sandwich structure middle layer and works well for transporting denser liquids at a consistent speed.
"The paper is treated with reagents and is let to dry. "Both paper layers are adhered to both sides of the support after drying, and the covers adhere with double-sided tape.
"Whatman filter paper grade 4 is used in this design, which aids liquid flow and allows for the storage of more reagents," said Pallab Sinha Mahapatra, associate professor, Department of Mechanical Engineering, and lead researcher of the study.
This new technology, say the researchers, is affordable, unlike conventional lab-based tests, which are expensive and time-consuming. The adulteration of milk is a growing menace, especially in developing countries like India, Pakistan, China, and Brazil.
Consumption of adulterated milk could cause medical complications such as kidney problems, infant death, gastrointestinal complications, diarrhoea, and even cancer.