Solve the problem of column durability
The analysis method of povidone K30 is described in detail in the 2020 edition of the "Chinese Pharmacopoeia", which mainly includes three test items: N-vinyl pyrrolidone, 2-pyrrolidone and formic acid. These test items all involve high-performance liquid chromatography.
1. **N-vinyl pyrrolidone**: Use octadecylsilane bonded silica gel as filler, acetonitrile-water (10:90) as mobile phase, and the detection wavelength is 235nm. The separation degree between the N-vinyl pyrrolidone peak and the vinyl acetate peak should be greater than 6.0.
2. **2-pyrrolidone**: Also use octadecylsilane bonded silica gel as filler, water-acetonitrile-methanol (90:5:5) as mobile phase, and the detection wavelength is 205nm. Inject 6 times, and the relative standard deviation of the peak area shall not exceed 2.0%.
3. **Formic acid**: Use octadecylsilane bonded silica gel as filler, 0.01mol/L potassium dihydrogen phosphate solution-acetonitrile (95:5) as mobile phase (adjust pH to 3.0 with phosphoric acid), and detection wavelength is 210nm.
During the analysis process, povidone K30 is easy to adhere to the chromatographic column, resulting in a long elution time, causing column contamination, thus affecting retention time and separation effect. To solve these problems, specific chromatographic columns can be used, which can be contacted. These chromatographic columns have high-purity silica gel and polymer coating technology, providing superior separation ability and stability.