论文部分内容阅读
目的建立一种阻抑溴酸钾氧化结晶紫褪色光度法测定芹菜中芹菜素的新方法。方法在0.05 mol/L盐酸介质中,结晶紫在588 nm处有最大吸收,当温度升高到85℃时,结晶紫能被溴酸钾很快氧化而褪色,而芹菜素能很好地抑制此褪色反应,并使体系在λmax=614 nm处的吸收随其浓度的增大而增强。体系吸收强度的变化值(△A)与芹菜素浓度在一定范围内呈现良好的线性关系,由此建立阻抑光度法来测定芹菜中的芹菜素含量。结果体系最大吸收波长为λmax=614 nm,而且其吸收强度变化值(△A)与芹菜素浓度在0.017~8.0μg/ml内线性关系良好,回归方程为△A=39.94 C(mg/ml)+0.106 1,相关系数r=0.998 6,检出限为5.1 ng/ml,加标回收率为98.4%~102.2%,RSD为0.62%~2.65%(n=6)。该方法用于芹菜中芹菜素含量的测定,结果满意。结论该方法操作简单、灵敏,仪器易得,能很好地应用于实际样品的分析。
OBJECTIVE To establish a new method for the determination of apigenin in celery by inhibiting the oxidation of crystal violet fading spectrophotometry of potassium bromate. Methods The crystal violet had the maximum absorption at 588 nm in 0.05 mol / L hydrochloric acid medium. When the temperature was raised to 85 ℃, the crystal violet could be quickly oxidized and discolored by potassium bromate, while the apigenin could well inhibit the discoloration Reaction, and the absorption of the system at λmax = 614 nm increased with the increase of its concentration. The change of absorbency (△ A) and the concentration of apigenin showed a good linearity within a certain range, and the inhibition spectrophotometry was used to determine the content of apigenin in celery. The results showed that the maximum absorption wavelength of the system was λmax = 614 nm, and the change of absorbance (△ A) was linear with the concentration of apigenin in 0.017 ~ 8.0 μg / ml. The regression equation was △ A = 39.94 C (mg / ml) +0.106 1, the correlation coefficient r = 0.998 6, the detection limit was 5.1 ng / ml, and the recoveries were 98.4% -102.2% with RSDs of 0.62% -2.65% (n = 6). The method was applied to the determination of apigenin in celery with satisfactory results. Conclusion The method is simple, sensitive and easy to obtain. It can be applied to the analysis of real samples well.