化学发光法测定巯嘌呤的含量

在流动注射系统中，利用巯嘌呤在碱性Luminol-K₃Fe(CN)₆化学发光体系中发光信号强的特点，建立了一种测定巯嘌呤的新方法。在优化条件下，方法的线性范围是1.02×10-7～1.02×10-9mol·L-1, 回归方程是Y=36.315c+140.72(Y是相对发光强度，c是巯嘌呤浓度与10-8 mol·L-1的乘积), 相关系数是0.998 2，检出限(S/N=3)是6.33×10-10mol·L-1,RSD为3.54%（c_i=2.0×10-9mol·L-1, n=12）。该法用于合成样品的测定，简便、灵敏、快速，结果令人满意。文章简要地探讨了巯嘌呤在碱性Luminol-K₃Fe(CN)₆化学发光体系中的化学发光机理：在反应过程中，产生大量的过氧自由基和羟基自由基，自由基与鲁米诺反应，形成激发态的鲁米诺分子，鲁米诺分子由激发态回到基态产生化学发光现象。

Chemiluminescence Determination of 6-Mercaptopurine in the Luminol-Potassium Ferricyanide System

A novel chemiluminescence (CL) method to determine 6-mercaptopurine (6-MP) is described, based on the catalytic effect of 6-MP on the CL reaction of luminol with K3Fe(C-N)6 in a flow system. Under optimal experimental conditions, the calibration graph is linear in the range of 1.02 x 10(-7) to 1.02 x 10(-9) mol x L(-1) 6-MP. The linear regression equation was Y = 36.315c + 140.72, where Y is the relative emission intensity and c is the concentration of 6-MP expressed in 10(-8) mol x L(-1) and the correlation coefficient is 0. 998 2 with the detection limits of 6. 33 X 10(-10) mol x L(-1) (S/N = 3). CL peak-height precision is 3.54% of RSD (n = 12) for a level of 2.0 x 10(-9) mol x L(-1). This method satisfactorily provides a fast, simple, sensible and favorable technique for the determination of 6-MP in synthesized samples in implementation. Moreover, the possible mechanism of CL enhancement was briefly discussed. Obviously, the reaction was related to the formation of free radicals. Thus, the CL emission could preliminarily be attributed to the process of energy transfer due to O2. radical and * OH radical resulting from the oxidation product of 6-MP by K3Fe(CN)6, which acts as an active intermediate that reacts with luminol, leading to the formation of excited luminol molecule, which gives out an emission when it returns to its ground state.