流动注射化学发光法快速测定中药黄芪中的痕量铬  

The rapid determination of trace chromium in medicine astragalus by flow injection chemiluminescence method

作　　者：焦艳娜[1] 任小蓉[1] 马红琼[1] 李晖[1] 庞国伟[1] 

机构地区：[1]四川大学,化学工程学院,成都610065

出　　处：《现代仪器》2008年第2期24-26,33,共4页Modern Instruments

摘　　要：利用Cr3+对鲁米诺-H2O2化学发光反应的催化作用,流动注射化学发光法的优点,建立测定Cr3+的新方法,并通过H2SO3的还原作用,使Cr6+还原为Cr3+,从而实现对总铬的测定。确定此方法的最佳条件:负高压500V;鲁米诺浓度为2.50×10-4mol/L;过氧化氢的浓度为4.00×10-2mo1/L,鲁米诺溶液的pH为12,铬(Ⅲ)试液的pH为5。线性范围为1.0×10-6mg/mL～1.0×10-4mg/mL,检出限(S/N=3)为6.60×10-7mg/mL,对浓度为6.00×10-6mg/mLCr3+的标准溶液进行11次平行测定,其相对标准偏差为0.6%。该法成功地实现对中药黄芪样品中痕量铬的测定。A new and effective method chemiluminescence-flow injection is established. It is based on the measurement of the light emitted from the Cr^3＋ -catalysed oxidation luminol by H2O2. Cr^6＋ is reduced to Cr^3＋ by H2SO3, thus the total chromium ion can be determined. Optimum conditions are obtained： applied voltage is -500V; luminol concentration is 2. 50×10^-4mol/L; hydrogen peroxide concentration is 4. 00 ×10^-2mol/L; pH of luminol is 12, pH of Cr （ m ） solution is 5. The linear range is 1.00 ×10^-6mg/mL - 1.0 ×10^-4mg/mL and detection limit is 6. 60 ×10^-7mg/mL （ S/N = 3 ） , The relative standard deviation （RSD） is 0.6% for 11 measurements of 6. 00 ×10^-6 mg/mL Cr^3＋ standard solution. The method has been successfully applied to the determination of chromium of the medicine samples Astragalus.

关 键 词：流动注射 化学发光 黄芪 铬 

分 类 号：O657.3[理学—分析化学] O614.611[理学—化学]