Precolumn fluorescence labelling of sodium valproate using 9-chloromethyl anthracene: Application to dosage form and spiked human plasma

An innovative spectrofluorimetric approach for determination of azelaic acid in bulk and pharmaceutical formulation through derivatization with 9-chloromethylanthracene

A novel simple, selective and accurate spectrofluorimetric method has been developed for quantitation of azelaic acid (AZA) in bulk and cream dosage form. The proposed method depended on the reaction between dicarboxylic moiety of AZA and 9-chloromethylanthracence to produce fluorescent derivative that exhibited maximum fluorescence intensity at 413 nm after being excited at 365 nm. The numerous experimental parameters which affect the reaction product and stability have been carefully studied and optimized. The linearity of the calibration curve constructed has been 0.5-15 µg/ml (y = 26.864x + 31.793, r² = 0.9999) with 0.143 and 0.434 µg/ml as LOD and LOQ values respectively. The method was used for quantitation of AZA in cream dosage form and the results showed that there was no interference from the cream excipients, the mean % recovery was 100.547% ± 0.775.

Recent Applications of Derivatization Techniques for Pharmaceutical and Bioanalytical Analysis through High-performance Liquid Chromatography

Background:

Derivatization of analytes is a quite convenient practice from an analytical perspective. Its vast prevalence is accounted by the availability of distinct reagents, primarily pragmatic for obtaining desired modifications in an analyte structure. Another reason for its handiness is typically to overcome limitations such as lack of sensitive methodology or instrumentation.The past decades have witnessed various new derivatization techniques including in-situ, enzymatic, ultrasound-assisted, microwave-assisted, and photochemical derivatization which have gain popularity recently.

Methods:

The online literature available on the utilization of derivatization as prominent analytical tools in recent years with typical advancements is reviewed. The illustrations of the analytical condition together with the structures of different derivatizing reagents (DRs) are provided to acknowledge the vast capability of derivatization to resolve analytical problems.

Results:

The derivatization techniques have enabled analytical chemists throughout the globe to develop an enhanced sensitivity method with the simplest of the instrument like High-Performance Liquid Chromatography (HPLC). The HPLC, compared to more sensitive Liquid chromatography coupled to tandem mass spectrometer, is readily available and can be readily utilized for routine analysis in fields of pharmaceuticals, bioanalysis, food safety, and environmental contamination. A troublesome aspect of these fields is the presence of a complex matrix with trace concentrations for analyses. Liquid chromatographic methods devoid of MS detectors do not have the desired sensitivity for this. A possible solution for overcoming this is to couple HPLC with derivatization to enable the possibility of detecting trace analytes with a less expensive instrument. Running cost, enhanced sensitivity, low time consumption, and overcoming the inherent problems of analyte are critical parameters for which HPLC is quite useful in high throughput analysis.

Conclusion:

The review critically highlights various kinds of derivatization applications in different fields of analytical chemistry. The information primarily focuses on pharmaceutical and bioanalytical applications in recent years. The various modes, types, and derivatizing reagents with brief mechanisms have been ascribed briefly Additionally, the importance of HPLC coupled to fluorescence and UV detection is presented as an overview through examples accompanied by their analytical conditions.