Determination of flavonoids by HPLC according to S & P Liquid A,. A liquid amount with the addition of methanol is diluted to 2/ml for the test solution B. Take B fluid 20 μL injection to adjust the instrument sensitivity, with the principal component peak height at 20% of full scale. Then take A sampling, record the chromatograms to twice the retention time of the main component peak. Obtain the total amount of impurities in the sample based on the ratio of the peak area of solution B and solution A miscellaneous peak area.
2 Results and discussion
2.1 The mobile phase measured under different conditions (Ren Bu save column), the capacity factor () and resolution (R) are shown in Table 1. Adding 0.1% acetic acid can increase the column efficiency and separation considering the above-mentioned chromatographic parameters, select a 0.1% methanol in water-acetic acid solution (75:25) as the mobile phase more appropriate.
2.2 Linear range and precision within the IP range of 2 ~ 100 μg / ml concentration (C) showed a good linear relationship between the peak area (A) measured under the experimental conditions set obtained. The regression equation is: A = 3028c +1465 = 0.9999 measured intra-day precision RSD = 0.42% (n = 5); day asked the precision with RSD of 0.88% (n = 3).
2.8 Detection limit based on three times the signal-to-noise ratio, the minimum detectable amount determined in these experimental conditions f/0v IP 0o = 4ng (port o = L II where S = N is the noise, c is the absolute injection the amount of the corresponding peak J.
Raw materials, samples confirm that the IP of the impurities that may exist related impurities for the intermediate 2-hydroxy-4-isopropoxy-phenyl acetophenone (-related) and 2,4-hydroxy benzene ethyl ketone (related objects). IP crude product correlate 1, correlate two different chromatographic conditions and IP samples were determined simultaneously, and compare chromatography figure impurity peak and related material peaks } the R value, the results show that under different conditions, each batch of IP samples of chromatograms-related tR Department had no significant impurity peak, while in the IP crude-related peak, related materials have been removed in the refining process, impurities in the sample chromatogram peak for the unknown impurities due to (see Figure 2).
HPLC circle of circle 1IP-related 1-IP2-related materials 13 - correlate two Chinese Journal of Pharmaceuticals Chlne ~ JournalofPharmac!! Zhu: Lan! Heartfelt chromatographic parameters measured under different conditions minister 2IP chromatogram of the impurities check Bu IP (dare 1m ~ / m1) 2 - solvent peak 3,4 - unknown impurity peaks
2.5 Determination of impurities check results of the different synthesis methods in the system of four batches of samples were measured (Table 2). The results show that an income products in terms of appearance and color purity of the product or products have rates better than Method 2.