An ultra-performance liquid chromatography-tandem mass spectrometric method for the identification and quantification of selected natural antioxidants in prickly pear samples

The aim of the present study was to develop a rapid, simple and reliable method for the identification and quantification of ten natural antioxidants in prickly pears using liquid chromatography with electrospray ionization tandem mass spectrometry. The analytical method was fully-validated, and calibration curves were established with correlation coefficients >0.99. A direct extraction method of analytes (ascorbic acid, catechin, gallic acid, isorhamnetin, kaempferol, luteolin, myricetin, quercetin, rutin, and taurine) with aqueous methanol resulted in a short analysis time and a good extraction efficiency. LOD values were from 0.17 to 15.0 mu g kg(-1) and LOQ values were from 0.50 to 45.4 mu g kg(-1) with recoveries ranging from 62.2 to 104.0 %. The expanded uncertainty was 9.7-19.0 % expressed at a coverage level of k = 2 at a confidence level of approximately 95 %. The method was successfully applied to yellow prickly pear samples from Cyprus. All above antioxidant compounds were present in all prickly pear samples analyzed except for Myricetin and Luteolin which were not detected in any of the samples.

Automated summary

The study aimed to develop a rapid, simple, and reliable method for identifying and quantifying ten natural antioxidants in prickly pears. The analytical method was validated and successfully applied to prickly pear samples from Cyprus, with all antioxidant compounds detected except for myricetin and luteolin.