In response to the comments by Betz, a description of the analytical method used to determine the monacolins and citrinin was indeed provided in our publication,1 though it may have been overlooked by readers because of reference formatting. The monacolins and citrinin were determined by the analytical method by Li et al,2 which was cited as reference 11 in our original article. The instruments and high-performance liquid chromatography (HPLC) column implemented for the analyses were described in the “Methods” section. Simultaneous analysis for citrinin was added to the Li method when it was determined during initial research that a similar extraction and HPLC method for separating and quantitating citrinin along with the monacolins was published (Lee et al,3 2006).
Obermeyer W, Cooperman T, Gordon RY, Becker DJ. Monacolin Levels in Red Yeast Rice: Methodological Questions—Reply. Arch Intern Med. 2011;171(10):941-954. doi:10.1001/archinternmed.2011.194