SEARCH Articles Figures Tables 1 : 4-Naphthoquinone 1,2-Naphthoquinone-4-sulfonic acid 2-semicarbazone 1,2-Naphthoquinone-4-sulfonic acid reagent L,2-Naphthoquinone-4-sulfonic acid Naphthoquinone-4-sulfonic Acid (Folin)