Taha Elham Anwer, Hassan Nagiba Yehya, Aal Fahima Abdel, Fattah Laila El-Sayed Abdel
National Organization for Drug Control and Research (NODCAR), 6 Abu Hazem. Pyramids, P.O. Box 29, Giza, Egypt.
J Fluoresc. 2007 May;17(3):293-300. doi: 10.1007/s10895-007-0172-6. Epub 2007 Apr 18.
Two simple, sensitive and specific fluorimetric methods have been developed for the determination of some sulphur containing compounds namely, Acetylcysteine (Ac), Carbocisteine (Cc) and Thioctic acid (Th) using terbium Tb+3 and uranium U+3 ions as fluorescent probes. The proposed methods involve the formation of a ternary complex with Tb+3 in presence of Tris-buffer method (I) and a binary complex with aqueous uranyl acetate solution method (II). The fluorescence quenching of Tb+3 at 510, 488 and 540 nm (lambda(ex) 250, 241 and 268 nm) and of uranyl acetate at 512 nm (lambda(ex) 240 nm) due to the complex formation was quantitatively measured for Ac, Cc and Th, respectively. The reaction conditions and the fluorescence spectral properties of the complexes have been investigated. Under the described conditions, the proposed methods were applicable over the concentration range (0.2-2.5 microg ml(-1)), (1-4 microg ml(-1)) and (0.5-3.5 microg ml(-1)) with mean percentage recoveries 99.74+/-0.36, 99.70+/-0.52 and 99.43+/-0.23 for method (I) and (0.5-6 microg ml(-1)), (0.5-5 microg ml(-1)), and (1-6 microg ml(-1)) with mean percentage recoveries 99.38+/-0.20, 99.82+/-0.28 and 99.93+/-0.32 for method (II), for the three cited drugs, respectively. The proposed methods were successfully applied for the determination of the studied compounds in bulk powders and in pharmaceutical formulations, as well as in presence of their related substances. The results obtained were found to be in agree statistically with those obtained by official and reported ones. The two methods were validated according to USP guidelines and also assessed by applying the standard addition technique.
已开发出两种简单、灵敏且特异的荧光分析法，用于测定某些含硫化合物，即使用铽（Tb³⁺）和铀（U³⁺）离子作为荧光探针来测定乙酰半胱氨酸（Ac）、羧甲司坦（Cc）和硫辛酸（Th）。所提出的方法包括在Tris缓冲液存在下与Tb³⁺形成三元络合物的方法（I）以及与醋酸双氧铀水溶液形成二元络合物的方法（II）。分别对Ac、Cc和Th定量测定了由于络合物形成导致的Tb³⁺在510、488和540 nm（激发波长λex为250、241和268 nm）处以及醋酸双氧铀在512 nm（激发波长λex为240 nm）处的荧光猝灭。研究了络合物的反应条件和荧光光谱特性。在所描述的条件下，方法（I）对于三种上述药物的适用浓度范围分别为（0.2 - 2.5 μg ml⁻¹）、（1 - 4 μg ml⁻¹）和（0.5 - 3.5 μg ml⁻¹），平均回收率分别为99.74 ± 0.36、99.70 ± 0.52和99.43 ± 0.23；方法（II）的适用浓度范围分别为（0.5 - 6 μg ml⁻¹）、（0.5 - 5 μg ml⁻¹）和（1 - 6 μg ml⁻¹），平均回收率分别为99.38 ± 0.20、99.82 ± 0.28和99.93 ± 0.32。所提出的方法成功应用于测定散装粉末和药物制剂中所研究的化合物，以及在其相关物质存在的情况下。发现所获得的结果在统计学上与官方和报道的结果一致。这两种方法根据美国药典指南进行了验证，并通过应用标准加入技术进行了评估。
