Furlanetto S, Pinzauti S, La Porta E, Chiarugi A, Mura P, Orlandini S
Department of Pharmaceutical Sciences, University of Florence, Firenze, Italy.
J Pharm Biomed Anal. 1998 Sep 1;17(6-7):1015-28. doi: 10.1016/s0731-7085(98)00067-3.
A chemometric approach was applied for determining quinolinic acid in human plasma by differential pulse polarography after solid phase extraction. A fractional factorial design was used to examine the significant experimental variables for the peak height maximization. A Doehlert design, which allowed a sequential response surface methodology to be performed, was applied to the variables scan rate and drop size. The results indicated that the scan rate had the greatest effect on the response peak height. The linear range was extended from 8.52 x 10(-8) to 1.34 x 10(-5) M and the limit of detection was 2.9 x 10(-8) M. The validation process consisted of a pre-validation study followed by the main validation in the plasma matrix. The robustness and the intermediate precision were evaluated by means of experimental design. A 3(4)//9 screening symmetric matrix and a central composite design were used to optimize the solid phase extraction procedure of the analyte from human plasma using anion exchange cartridges. The goal was to select the best retention, wash and elution solvents and their volumes in order to maximize the extraction efficiency using as the response the polarographic peak height. An extraction efficiency of 90% was found. The method was also applied to the determination of quinolinic acid in urine and the mean concentration in human plasma and urine, was found to be 3.7 x 10(-7) and 4.9 x 10(-5) M respectively.
采用化学计量学方法，通过固相萃取后的差分脉冲极谱法测定人血浆中的喹啉酸。使用部分因子设计来研究使峰高最大化的重要实验变量。将允许进行顺序响应面法的Doehlert设计应用于扫描速率和滴汞大小变量。结果表明，扫描速率对响应峰高影响最大。线性范围从8.52×10⁻⁸扩展至1.34×10⁻⁵ M，检测限为2.9×10⁻⁸ M。验证过程包括预验证研究，随后在血浆基质中进行主要验证。通过实验设计评估稳健性和中间精密度。使用3⁴//9筛选对称矩阵和中心复合设计来优化使用阴离子交换柱从人血浆中萃取分析物的固相萃取程序。目标是选择最佳的保留、洗涤和洗脱溶剂及其体积，以使用极谱峰高作为响应来最大化萃取效率。发现萃取效率为90%。该方法还应用于尿液中喹啉酸的测定，发现人血浆和尿液中的平均浓度分别为3.7×10⁻⁷和4.9×10⁻⁵ M。
