This detector detects melamine in milk
Q. Melamine detector has been developed by IISC researchers in which substance?- Published on 30 Sep 16a. Water
b. Milk
c. Liquids
d. None of the above
ANSWER: Milk
Detecting melamine in milk has become easy and cost efficient thanks to a handheld melamine detector developed by researchers at IISc Bangalore.
- Leaf extract of the weed parthenium along with silver nitrate is used for diagnosing the presence of melamine in milk
- Through change in colour, presence of melamine in milk can be detected at room temperature within a few seconds
- Sensor has sensitivity in detecting melamine to the extent of 0.5 ppm in raw milk
- Melamine content of 1 ppm/more in infant formula and more than 2.5 ppm in other milk products means it is adulterer
- Due to the presence of nitrogen, adding melamine to milk makes it look protein-rich.
- Prior to melamine detection, the milk undergoes processing to remove fat and proteins as they tend to interfere with detection.
- IISc team added silver nitrate and the leaf extract in a particular ratio and at a particular pH to the preprocessed milk to synthesise silver nanoparticles.
- The silver nanoparticles are reddish-yellow in the absence of melamine; they become nearly colourless when melamine is present.
- Light absorption at 414 nm wavelength is a signature of silver nanoparticles.
- When melamine is present, then the absorption of light is reduced as nanoparticle formation decreases.
