Simultaneous determination of nine preservatives in fruits and vegetables by high performance liquid chromatography with programmed wavelength UV detection

A method of simultaneous determination of nine preservatives, namely, paraben preservatives (methyl paraben, ethyl paraben, propyl paraben, butyl paraben, isopropyl paraben, isobutyl paraben, 2-naphthalenol, ethoxyquin and p- phenylphenol) in orange, cucumber, cabbage and tomato by high performance liquid chromatography with programmed wavelength UV detection was developed. The samples were extracted with diethyl ether, then cleaned up with liquid-liquid extraction, separated with a Agilent Eclipse XDB-C18 column (150mm×4.6mm, 3.5μm) using methol-water as mobile phase with a gradient elution program, determined with variable wavelength detector, and quantified with external standard curve. The nine preservatives had good linear relationships in the range of 0.5¹00.0mg/L, the correlation coefficients were higher than 0.9991. Average recoveries of the nine preservatives at spiking levels of 50, 200, 500μg/kg were 70.7% ¹19.5% and relative standard deviations were 0.9%⁹.9%. The method developed is simple, rapid and accurate, and can be used for the determination of trace residues of nine preservatives in fruits and vegetables.