Analysis of Salicylic Acid in Tobacco Leaves Using Capillary Zone Electrophoresis with UV Detection

Abstract

AbstractA simple and inexpensive capillary zone electrophoresis (CZE) with UV detection method was used to determine salicylic acid (SA) and six structural analogs (benzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, acetylsalicylic acid, methyl salicylate, and jasmonic acid). All of the compounds were successfully separated within a migration period of 6 min, with a high number of theoretical plates (>37,000, calculated using the width at the base of the SA peak), in 20.0 mmol L-1 Na2HPO4/H3BO3 buffer (pH 9.0) containing 2.0% methanol and 2.0% acetonitrile. The regression line for SA was linear over the range 0.5–200 µmol L-1. Both the intra- and inter-day precisions of the migration time (relative standard deviations, RSDs, 0.6% and 4.7%, respectively) and peak area (RSDs 0.9% and 7.3%, respectively) were acceptable. The proposed method was used to determine the SA concentrations in tobacco leaves ( Nicotiana tabacum L.) from the Xanthi-nc ( NN genotype) and the Nt-NahG mutant strains that had been irradiated with UV (254 nm) for 20 min and the ones that had not been irradiated. Rapid separation (<6 min), good reproducibilities (RSDs < 11.9%), and good recoveries (94.7–118%) were obtained in the tobacco leaf analyses.