Have you ever worked with new methods and said to yourself “yes I know what these internal standards and surrogates are measuring and when to add them to the samples”? Sounds familiar right? Well, I remember when I first started working in the laboratory and needed to fully understand and follow all method protocols and standard operating procedures (SOPs). One of the questions I asked was, what is the difference between method 525.2 and its internal standard and surrogates versus every other method we extract and analyze?