Highly Sensitive Spectrofluorimetric Determination of Trace Amounts of Folic Acid using a Oxytetracycline-Terbium(III) Probe

Abstract

A new spectrofluorimetric method was developed for the determination of trace amounts of folic acid using oxytetracycline–terbium ion complex as a fluorescent probe. In the buffer solution of pH 6.00, folic acid remarkably reduced the fluorescence intensity of the oxytetracycline–terbium complex at λ = 545 nm. The reduced fluorescence intensity of the Tb³⁺ ion was proportional to the concentration of folic acid. Optimum conditions for the determination of folic acid were investigated. This method was simple, practical, and relatively free of interference from coexisting substances. Furthermore, it was successfully applied to assess folic acid in tablet, injection, and urine samples.

Keywords:

• Folic acid
• oxytetracycline
• spectrofluorimetry
• terbium

The authors acknowledge the support from National Natural Science Foundation of China (20805016), the Science Foundation of Huazhong University of Science and Technology (0101013008), and the Science Foundation of Huaibei Coal Industry Teachers' College.

Notes

^a Chemiluminescence.

^b High-performance liquid chromatography.

^c Liquid chromatography–mass spectrometry.

^d Capillary electrophoretic method.

^a From Changzhou Pharmaceutical Co., Ltd., Jiangsu, China (No. H32023302), Minghua Pharmaceutical Co., Ltd., Fujian, China (No. H19983051), Yu'an Pharmaceutical Co., Ltd., Shanghai, China (No. H20020575), Puqiang Pharmaceutical Co., Ltd., Jiangsu, China (No. H 20010804), and Yi'ou Pharmaceutical Co., Ltd., Sichuan, China (No. H20010615).

^b 5 mg/injection.

Note. RSD, relative standard deviation.

^a From a healthy volunteer in a local hospital, Wuhan, China.

^b Mean ± SD. Average of six determinations.