Direct injection and determination of the active principles of spices using micellar liquid chromatography

Abstract

In this work, we develop a simple chromatographic method to identify and determine three active principles: curcumin, capsaicin and piperine. These compounds are present as spices in some plants: turmeric (Curcuma longa), red pepper (Capsicum annuum) and black pepper (Piper nigrum). The method includes a micellar mobile phase containing 0.15 M sodium dodecyl sulphate and 12.5% (v/v) propanol buffered at pH 7, a Kromasil C18 column (125 mm × 4.6 mm, 5 μm particle size) and UV detection set at 210 nm. The micellar liquid chromatography (MLC) method herein reported is simple, sensitive, precise, robust, and samples can be directly injected into the column without any pre-treatment step. Under these conditions, analysis times were below 7 min for the complete resolution of the three compounds. Linearity (r > 0.9998), limits of detection of 0.7, 1.3 and 5 ng/mL and limits of quantification of 2, 4.4 and 15 ng/mL, for capsaicin, curcumin and piperine, respectively, intra- and inter-day precision (RSD, %) less than 5.9, were studied in the method validation. Finally, the MLC method was applied to spiked samples, with recoveries of around 100%, and in nine real samples, and with amounts of spices in the 0.02 and 47.1 mg/g range. The simplicity of the method makes it a good candidate to be used in routine analyses in the area of food control and quality. © 2009 Elsevier Ltd. All rights reserved.