This study developed a new and simple SHS–GC–MS method to determine up to 10 HAAs in milk and dairy products. The sample treatment includes the precipitation of proteins and centrifugation, and simultaneous derivatization/extraction of the HAAs present in the supernatant, in an automatic SHS module. The method achieves good linearity and precision, with LODs ranging between 0.02 and 0.50 l gL. From the samples analyzed, we can conclude that about 20% of them contain DCAA and TCAA at concentrations below 2 l gL, which can be ascribed to contamination from sanitizers employed in the dairy industry. The process of boiling tap water did not remove the HAAs and therefore powdered infant formula should be prepared with mineral water (free of DBPs). In addition, it is possible to establish if the milk has been adulterated with treated water through the determination of HAAs