Determination of ortho-phenylphenol residues in lemon rind by high-performance liquid chromatography with electrochemical detection using a microbore column.
A simple and highly sensitive method has been developed for determining ortho-phenylphenol (OPP) in lemon rind by high-performance liquid chromatography with electrochemical detection using a microbore column (microHPLC-ECD). Based on the voltammetric behavior of OPP, microHPLC-ECD was established using a CAPCELL PAK C-18 UG 120 microbore ODS column, 17 mM acetic acid-sodium acetate buffer (pH 4.0)/acetonitrile (60/40, v/v) as a mobile phase and an applied potential at +0.9 V vs. Ag/AgCl. The current peak height was found to be linearly related to the amount of OPP injected from 3.4 pg to 1.7 ng (r > 0.999). The detection limit (S/N = 3) was 3.4 pg (20 fmol), which was 100 times greater in terms of sensitivity when compared to conventional HPLC with UV detection. Standard OPP at 0.425 ng was detected with a relative standard deviation (RSD) of 1.9% (n = 10). The OPP contents in several lemon samples were determined by the present method. The recoveries of OPP from lemon rind exceeded 98% with an RSD (n = 5) of less than 3.01%.
Yang
Lan
L
School of Pharmacy, Tokyo University of Pharmacy and Life Science, Horinouchi 1432-1, Hachioji, Tokyo 192-0392, Japan.
Kotani
Akira
A
Hakamata
Hideki
H
Kusu
Fumiyo
F
D001713:Biphenyl Compounds / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D004563:Electrochemistry / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000032:analysis*
D001713:Biphenyl Compounds; D005659:Fungicides, Industrial; C004369:2-phenylphenol