Level 1: identification by retention times (compared against in-house authentic standards), accurate mass (with an accepted deviation of 3 ppm), and MS/MS spectra, Level 2a: identification by retention times (compared against in-house authentic standards), accurate mass (with an accepted deviation of 3ppm)
Griendling KK, Touyz RM, Zweier JL, Dikalov S, Chilian W, Chen YR, Harrison DG, Bhatnagar A, American Heart Association Council on Basic Cardiovascular Sciences
Labib, HM, et al (2010)
Unsurprisingly, the industry related to preventing or covering up this loss of hair colour is estimated to be worth tens of billions of dollars globally a year, and the wild west that is social media has supercharged the number of people claiming their products can prevent or reverse early greying