Jatlow P
Clin Chem. 1975 Sep;21(10):1518-20.
Ultraviolet spectrophotometry is widely used for the analysis of theophylline in blood, for purposes of monitoring therapy, and for pharmacokinetic studies. Phenobarbital, a component of common oral theophylline preparations, interferes with assays now in use. The modification of the method of Schack and Waxler [J. Pharmacol. Exp. Ther. 97, 283 (1949)] presented in this paper eliminates barbiturate interference. After solvent extraction and back extraction into NaOH, the pH of the alkaline solution is adjusted from pH 13 to 10 before spectrophotometric measurement. This shifts the barbiturate absorption maximum from 255 to 240 nm, permitting accurate analysis of theophylline, the spectrum of which is unaffected by the pH change.
紫外分光光度法广泛用于血液中茶碱的分析，以监测治疗效果和进行药代动力学研究。苯巴比妥是常见口服茶碱制剂的一种成分，会干扰目前使用的检测方法。本文介绍的对Schack和Waxler [《药理学与实验治疗学杂志》97, 283 (1949)]方法的改进消除了巴比妥类药物的干扰。在溶剂萃取并反萃取到氢氧化钠中后，在进行分光光度测量之前，将碱性溶液的pH从13调至10。这将巴比妥类药物的最大吸收波长从255 nm移至240 nm，从而能够准确分析茶碱，其光谱不受pH变化的影响。
