Spectrophotometric Determination of Curcumin using 3-Methyl-2-benzothiazolinone Hydrazone Hydrochloride Hydrate as Electrophilic Coupling Agent

Abstract

Nutraceuticals are products derived from food sources that provide extra health benefits in addition to the basic nutritional value found in foods. Spectrophotometric methods for the determination of curcumin were developed, which are simple, sensitive, selective, rapid, and reliable. The methods are based on the reduction of iron (III) to iron (II) by 3-Methyl-2- benzothiazolinone hydrazone hydrochloride hydrate (MBTH), which is an electrophilic coupling agent and subsequent reaction with curcumin in mild hydrochloric acid medium. Spectrophotometric methods for the determination of curcumin were developed, which are simple, sensitive, selective, rapid, and reliable. The methods are based on the reduction of iron (III) to iron (II) by 3-Methyl-2-benzothiazolinone hydrazone hydrochloride hydrate (MBTH), which is an electrophilic coupling agent and subsequent reaction with curcumin in mild hydrochloric acid medium. The reaction produces a bluish–green complex with maximum absorbance at 670 nm. The colour complex can be extracted into chloroform. The methods obey Beer’s law in the range 0.3-7.0 and 0.2-7.0 (µg mL-1 ). 10 common anions and cations were added, and the method was tested, and no interference was observed. The proposed methods offered the advantages of having good reproducibility and were satisfactorily worked out to estimate the amount of curcumin in various turmeric samples.