Determinación cuantitativa de indigotina e indirubina en el índigo natural mediante cromatografía líquida de alto rendimiento (HPLC) (Quantitative HPLC determination of indigotin and indirubin in indigo naturalis)

g/ml for indigotin and indirubin, respectively. A high degree of specificity and robustness, as well as repeatability (relative standard deviation less than 5% for both standards and the extracts) and accuracy (% recoveries greater than 95%) were also achieved.