Murillo Pulgarín J A, Alañón Molina A, Alañón Pardo M T
Department of Analytical Chemistry and Food Technology, University of Castilla-La Mancha, 13071, Ciudad Real, Spain.
Analyst. 2001 Feb;126(2):234-8. doi: 10.1039/b008541n.
A selective and sensitive room temperature phosphorimetric method for the direct determination of naftopidil in biological fluids is described. The method is based on obtaining a phosphorescence signal from this antihypertensive drug using TlNO3 as a heavy atom perturber and Na2SO3 as a deoxygenator agent without a protective medium. This technique is named non-protected room temperature phosphorescence (NP-RTP), and enables us to determine analytes in complex matrices without the need for a tedious prior separation process. The optimization of Na2SO3 (8.5 x 10(-3) M) and the accurate value of pH (9.0) were determined using a simplex as a method of optimization. Sodium carbonate-hydrogencarbonate buffer solution (5.0 x 10(-2) M) was used to adjust the suitable pH. The optimum concentration of Tl+ (8.5 x 10(-2) M) was also determined. The delay time, gate time and time between flashes selected were 200 microseconds, 200 microseconds and 5 ms, respectively. Under the above conditions we propose a method to determine naftopidil by direct measurement of phosphorescence intensity with an emission wavelength of 526 nm and an excitation wavelength of 296 nm in the concentration range 0.05-1.00 mg L-1. Under these conditions the phosphorescence signal appears in 3 min once the sample has been prepared. Optimization of the various conditions permitted the establishment of an NP-RTP method for the determination with a detection limit, according to the error propagation theory, of 21.0 ng mL-1. The repeatability was studied using 10 solutions of 0.20 mg L-1 of naftopidil; if error propagation is assumed, the relative error is 1.39%. The standard deviation for replicate samples was 1.1 x 10(-2) mg L-1. This method was successfully applied to the determination of naftopidil, in human urine with recoveries between 106 and 112%.
本文描述了一种用于直接测定生物体液中萘哌地尔的选择性灵敏室温磷光法。该方法基于在无保护介质的情况下，以硝酸铊作为重原子微扰剂、亚硫酸钠作为除氧剂，从这种抗高血压药物获得磷光信号。此技术被称为非保护室温磷光（NP-RTP），它使我们能够在无需繁琐的预先分离过程的情况下，测定复杂基质中的分析物。使用单纯形法作为优化方法确定了亚硫酸钠（8.5×10⁻³ M）的优化值和准确的pH值（9.0）。使用碳酸氢钠-碳酸钠缓冲溶液（5.0×10⁻² M）来调节合适的pH值。还确定了铊离子（8.5×10⁻² M）的最佳浓度。所选的延迟时间、门控时间和闪光间隔时间分别为200微秒、200微秒和5毫秒。在上述条件下，我们提出了一种通过在发射波长526 nm和激发波长296 nm下直接测量磷光强度来测定萘哌地尔的方法，浓度范围为0.05 - 1.00 mg L⁻¹。在这些条件下，一旦样品制备好，磷光信号在3分钟内出现。各种条件的优化使得能够建立一种NP-RTP测定方法，根据误差传播理论，检测限为21.0 ng mL⁻¹。使用10份浓度为0.20 mg L⁻¹的萘哌地尔溶液研究了重复性；如果假设误差传播，相对误差为1.39%。重复样品的标准偏差为1.1×10⁻² mg L⁻¹。该方法成功应用于测定人尿中的萘哌地尔，回收率在106%至112%之间。
