Department of Chemistry, Faculty of Science, Zanjan University, Zanjan, 45195-313, Iran.
J Fluoresc. 2012 Jan;22(1):365-71. doi: 10.1007/s10895-011-0968-2. Epub 2011 Sep 20.
In this work, a new simple and sensitive flow injection method is developed for the determination of homocysteine with spectrofluorimetric detection technique. This method is based on the oxidation of homocysteine with Tl (III) in acidic media, producing fluorescence reagent, TlCl(3)(2-) (λ(ex) = 237 nm, λ(em) = 419 nm). The effects of chemical parameters (including pH of the solutions, the buffer, Tl (III) and potassium chloride concentrations), instrumental parameters (such as flow rate of the solutions, reaction coil length, and sample loop volume) and temperature on the fluorescence intensity as an analytical signal are studied and optimized. In the optimum conditions of the above variables, homocysteine can be determined in the range 4.0 × 10(-7)-40.0 × 10(-6) M with the LDR from 4.0 × 10(-7) to 25.0 × 10(-6) M. The detection limit (with S/N = 3) is 6.0 × 10(-8) M of homocysteine and precision for the injection of 5.0, 10.0 and 15.0 μM of homocysteine are 0.8%, 1.5% and 2.5% (n = 10) respectively. The rate of analysis is 90 samples per hour. The influence of potential interfering substances, including amino acids and carbohydrates is also studied. The proposed method has been successfully used for the determination of homocysteine in the real sample (blood serum and tap water) matrix.
在这项工作中，开发了一种新的简单灵敏的流动注射法，用于用荧光检测技术测定同型半胱氨酸。该方法基于在酸性介质中用 Tl(III)氧化同型半胱氨酸，产生荧光试剂 TlCl(3)(2-)（λ(ex)=237nm，λ(em)=419nm）。研究并优化了化学参数（包括溶液的 pH 值、缓冲液、Tl(III)和氯化钾浓度）、仪器参数（如溶液流速、反应盘管长度和样品环体积）和温度对荧光强度作为分析信号的影响。在上述变量的最佳条件下，同型半胱氨酸可在 4.0×10(-7)-40.0×10(-6) M 的范围内测定，线性范围从 4.0×10(-7)到 25.0×10(-6) M。同型半胱氨酸的检测限（S/N=3）为 6.0×10(-8) M，注入 5.0、10.0 和 15.0 μM 同型半胱氨酸的精密度分别为 0.8%、1.5%和 2.5%（n=10）。分析速度为每小时 90 个样品。还研究了包括氨基酸和碳水化合物在内的潜在干扰物质的影响。该方法已成功用于测定血清和自来水中的同型半胱氨酸。
