Measurements of δD and δ18O Stable Isotope Ratios in Milk

: This study explores the possibility of distinguishing raw and reconstituted milk by stable isotope ratio mass spectrometry. Considering variations from different areas and seasons, milk and groundwater samples were collected from dairy farms in different seasons to measure δD and δ18O values. Results showed differences between raw and reconstituted milk prepared with groundwater from a laboratory and a farm. The plot of values in each mixed level of raw and reconstituted milk had a correlation coefficient > 0.9. Data showed raw milk is related to the groundwater from that farm. We concluded that the charcoal treatment method is a suitable method for large-scale monitoring of raw milk samples. The measurement of δD and δ18O values in raw milk and groundwater provides a reference to detect adulteration.