Milk is a common target for adulteration, which is of significant concern to both producers and consumers. Some common milk adulterants include water, whey, sodium hydroxide, urea, melamine and other potentially harmful substances. The purpose of adulterating milk is to artificially increase the volume and/or mask inferior quality product for economic gain.
For this reason, there is significant interest in rapid, easy to use analytical methods that can detect if milk is adulterated and then measure the levels of the adulterants in milk. In a recent publication researchers measured adulterants in milk in the laboratory using the Agilent Cary 630 FTIR spectrometer and showed that the mid FTIR system is superior to NIR spectroscopy for these determinations.
Two distinct methods will be described for measuring adulteration in milk:
- A screening method to detect that an adulteration has taken place, using an Agilent FTIR analyzer equipped with DialPath sampling technology
- Identification and measurement of specific adulterants, using an Agilent FTIR analyzer equipped with diamond ATR sampling technology
In the screening method, the milk is measured directly with no sample preparation, leading to an extremely fast analysis. Using this technique on the dedicated Agilent 5500 or 4500 FTIR spectrometer allows for efficient screening at the point of delivery.
To get accurate identification and measurement of the adulterant, a second method is employed that uses simple sample preparation steps. This latter technique provides a fast alternative to classical analytical methods of determining milk contamination levels.
Agilent FTIR analyzers equipped with DialPath transmission sampling technology provide an easy-to implement, rapid method for screening milk samples for tampering to as low as 3% v/v dilution. These systems equipped with single reflection diamond ATR sampling technology afford measurement of specific common adulterants in dry milk films. For laboratories located at dairy processing sites, this combination of technology and methodology offers a time and cost saving alternative to traditional methods of milk analysis.