Fig. 7From: Applicability of enzymatic and phenol–sulfuric acid methods for determination of cellulose nanofibers in ecotoxicity testingQuantitative measurement of CNFs using the phenol–sulfuric acid method. CNFs in ultrapure water (a), USEPA moderately hard water (b), and OECD medium (c) were measured using the phenol–sulfuric acid method. Error bars: standard deviations (n = 4–5)Back to article page