title: Determination of total phthalates in edible oils by high-performance liquid chromatography coupled with photodiode array detection.
abstract: The previously reported procedure for the determination of the total phthalate in fatty food involved the extraction of phthalates using chloroform/methanol followed by the removal of the solvents before alkaline hydrolysis requiring 20 h and derivatization of phthalic acid. In this study, a phase-transfer catalyst (tetrabutylammonium chloride) was used in the liquid-liquid heterogeneous hydrolysis of phthalates in oil matrix shortening the reaction time to within 25 min. The resulting phthalic acid in the hydrolysate was extracted by a novel molecular complex based dispersive liquid-liquid microextraction method coupled with back-extraction before high-performance liquid chromatography coupled with photodiode array detection. Under the optimal experimental conditions, the linearity of the method was in the range of 0.5-12 nmol/g with the correlation coefficients (r) >0.997. The detection limit (S/N = 3) was 0.11 nmol/g. Intraday and interday repeatability values expressed as relative standard deviation were 3.9 and 7.1%, respectively. The recovery rates ranged from 82.4 to 99.0%. The developed method was successfully applied for the analysis of total phthalate in seven edible oils.
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi, China.
authors.forename: Qilong
authors.initials: Q
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi, China.
authors.forename: Dekui
authors.initials: D
authors.lastname: Sun
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Yangying
authors.initials: Y
authors.lastname: Han
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi, China.
authors.forename: Litao
authors.initials: L
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hou
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Shuhui
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi, China.
authors.forename: Debao
authors.initials: D
authors.lastname: Li
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D005506:Food Contamination / Q000032:analysis; D059627:Liquid Phase Microextraction; D010795:Phthalic Acids / Q000032:analysis* / Q000302:isolation & purification; D010938:Plant Oils / Q000737:chemistry*
chemical_list: D010795:Phthalic Acids; D010938:Plant Oils; C032279:phthalic acid
keywords: Dispersive liquid-liquid microextraction; Edible oils; Phthalate sum; Phthalic acid; Tetrabutylammonium chloride