Sponsor's Content: The increased use of hormone-based therapies in health care throughout the world has resulted in hormones finding their way into municipal water supplies. The potential health risks of unintended consumption of hormones through drinking water have significantly increased the interest in identifying these compounds in our water supplies. The Milli-Q system incorporates a combination of purification processes that provides ultrapure, hormone-free lab water for the LC–MS techniques used for interference-free analysis of these contaminants.