Objective: To establish a rapid determination of total phenols in Dendrobii Officinalis Caulis. Method: Folin-Ciocalteu Colorimetry was adopted to determine the content of total phenols in Dendrobii Officinalis Caulis by taking ferulic acid as a reference.Single factor tests were adopted to screen chromogenic conditions

such as detection wavelength

chromogenic time and temperature

et al;With the content of total phenols as index

effects of ethanol concentration

solid-liquid ratio

extraction time and times on extraction technology of total phenols were investigated by L9(34) orthogonal test

in order to define preparation method of the test solution for determination. Result: Chromogenic conditions were as follows:detection wavelength 760 nm

the amount of Folin-Ciocaileu reagent 3.5 mL

the amount of 10% sodium carbonate solution 7 mL

chromogenic temperature 20-30℃

dark reaction time 0.5 h.Optimum extraction of total phenols from Dendrobii Officinalis Caulis was as following:extracted 1 h with 40 times the amount of 70% ethanol.The concentration of ferulic acid had a good linear relationship in range of 3.168-9.504 mg·L-1

average recovery was 97.9% with a corresponding RSD of 1.53% (n=6). Conclusion: This determination method was simple

rapid

accurate

stable and reproducible for determining the content of total phenols in Dendrobii Officinalis Caulis.