Analysis of Carotenoids and Their Isomers in Tomatoes by HPLC Method

KeyWord:high performance liquid chromatography£¨HPLC£©  carotenoids  cis isomers  tomato

Abstract:

      An analytical method was developed for the determination of carotenoids and their isomers in tomatoes by an improved high performance liquid chromatography£¨HPLC£© method.Hexane-ethanol£¨3¡Ã4£© was chosen as the best solvent system for extracting carotenoids from tomatoes by stirring 30 min using a magnetic stirring apparatus.11 kinds of carotenoids including all trans forms of lycopene£¬¦Â-carotene£¬lutein and 8 kinds of cis-isomers were completely separated in 30 min on a Carotenoid C30 column£¨250 mm¡Á4.6 mm i.d.£¬5 ¦Ìm particle£© using methyl tert-butyl ether£¨MTBE£© containing 0.05% triethylamine£¨TEA£© as mobile phase A and acetonitrile containing 0.05% TEA as mobile phase B by gradient elution.The flow rate was set at 1.0 mL/min£¬and the detection wavelength was 475 nm.For lutein£¬¦Â-carotene and lycopene£¬the calibration curves were linear in the ranges of 0.1-5.0£¬0.1-20 and 0.1-100 ¦Ìg/mL,respectively£¬with correlation coefficients more than 0.99.The limits of detection£¨LOD£© were 0.13£¬0.12,0.56 ¦Ìg/g£¬respectively£¬the limits of quantitation£¨LOQ£© were 0.43£¬0.41,1.88 ¦Ìg/g£¬respectively.The intra-day relative standard deviation£¨RSD£© were in the range of 1.2%-5.3%£¬and the inter-day RSDs were 1.9%-7.5%.The recoveries were in the range of (88.9¡À6.1)%-(91.7¡À3.6)%£¬(92.3¡À4.3)%-(94.1¡À6.3)% and £¨102.6¡À4.2£©%-(107.1¡À3.4£©%£¬respectively.This HPLC method could be used to separate 11 types of carotenoids in tomatoes completely with a short time and high sensitivity.