建立NaNO₂-Al(NO₃)₃-NaOH比色法，测定乳苣不同部位及其全草总黄酮含量。一定量样品液加5% NaNO2溶液2.00 ml，摇匀，放置6 min，10% Al(NO₃)₃溶液2.00 ml，摇匀，放置6 min，加4% NaOH溶液12.00 ml，蒸馏水定容至刻度，摇匀，静置15 min，于522 nm下测定吸光度，黄酮含量在0.0080~0.0720 mg/ml范围内与吸光度具有良好的线性关系。精密度和稳定性试验RSD分别为1.5%和2.9%，平均回收率93.61%，有较好的的精密度和准确度。本试验测得乳苣根、茎、叶及全草总黄酮提取率依次为：叶(105.4 mg/g) > 全草(77.63 mg/g) > 茎(12.60 mg/g) > 根(11.64 mg/g)，由此可知乳苣总黄酮主要集中在地上部分。
A NaNO₂-Al(NO₃)₃-NaOH colorimetric method was established to determine the total flavonoids content in different parts of Mulgedium tataricum L and its whole grass. A certain amount of sample solution was added with 2.00 ml of 5% NaNO₂ solution, shaken, and placed for 6 minutes, added with 12.00 ml of 4% NaOH solution, and distilled water to determine Volume up to the mark, shake well, stand for 15 min, measure the absorbance at 522 nm, the flavonoid content in the range of 0.0080~0.0720 mg/ml has a good linear relationship with the absorbance. The RSD of the precision and stability tests were 1.5% and 2.9%, respectively, and the average recovery rate was 93.61%, with good precision and accuracy. In this experiment, the extraction rate of total flavonoids from the roots, stems, leaves, and whole plants of Nicotiana officinalis was as follows: leaves (105.4 mg/g) > whole plants (77.63 mg/g) > stems (12.60 mg/g) > roots (11.64 mg/g), it can be seen that the total flavonoids of Mulgedium tataricum L. are mainly concentrated in the above-ground part.