摘要
为了更好地采用1,1-二-苯基-2-苦基肼自由基（DPPH）评价物质的抗氧化能力,采用电子顺磁共振法对DPPH进行了研究.采用自动调模法寻找共振频率,从而实现严格偶合.设定调制频率为100kHz,调制幅度为1 GT,在0～9 500 GT范围内寻找样品的电子顺磁共振谱图,并确定中心磁场和扫描宽度.分别改变微波功率、时间常数、接收机增益及x轴的扫描次数,运行后得到不同条件下的电子顺磁共振谱图.得到的实验优化条件：DPPH浓度0.5 mmol/L,中心磁场3522.33 GT,扫描宽度100 GT,调制频率100 kHz,调制幅度1 GT,接收机增益5.02×104,时间常数10.24 ms,扫描次数3次.在优化后的实验条件下测得的DPPH的g因子,与其理论值2.003 6接近.
1,1-diphenyl-2-picrylhydrazyl （DPPH） is studied by electron paramagnetic resonance （EPR） in order to evaluate antioxidatin ability of substance with it.Turning automatically is used to search the resonance frequency to realize critical coupling.The EPR plot of the sample is searched between 0 and 9 500 GT with the modulation frequency of 100 kHz and modulation amplitude of 1 GT,and the center field and the sweep width are set on.The microwave power,time constant,receiver gain and the scanning times of x-axis are changed respectively.The EPR plots under different conditions are obtained after running.The optimum experiment conditions are obtained.The DPPH concentration is 5.0 × 10-4 mol/L,the center field is 3 522.33 GT,the sweep width is 100 GT,the modulation frequency is 100 kHz,the modulation amplitude is 1 G,the receiver gain is 5.02 × 104,the time constant is 10.24 ms,and the number of X-scan is 3.The g factor of DPPH determined under the optimum conditions is nearby to its theory value （2.003 6）.The innovating dots are study on saturated property of DPPH and systematic discussion of the determination condition of DPPH by EPR.
出处
《实验室研究与探索》
CAS
北大核心
2013年第9期51-53,共3页
Research and Exploration In Laboratory
