title: The application of directly suspended droplet microextraction for the evaluation of phthalic acid esters in cow's milk by gas chromatography mass spectrometry.
abstract: A simple and rapid method was developed for evaluating 16 phthalic acid esters (PAEs) at the μg/kg level in a complex milk matrix using directly suspended droplet microextraction-gas chromatography mass spectrometry (DSDME-GC-MS). The different parameters for extraction and for the DSDME experiment were optimized, including You are free to submit the revised manuscript at a later date as a new submission. 10 g/L trichloroacetic acid concentration, 100 μL cyclohexane micro-droplet organic solvent, 1100 rpm stirring speed, 10 min extraction time and no salt amount. Validation experiments showed good linearity (γ>0.9878, 0.002-0.4 μg/mL), satisfactory precision (RSD<11%), and good accuracy (relative recovery of 70.2-108%) when analyzing milk samples using the optimized method. The limits of detection (LODs) ranged between 0.001 and 0.2 μg/L, and the limits of quantification (LOQs) ranged between 0.003 and 0.7 μg/L for 15 PAEs. Dinonyl phthalate (DINP) had a low response and did not have good linearity. The proposed method was successfully applied for the analysis of PAEs in real milk samples.
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China. Electronic address: dliu@cau.edu.cn.
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China.
authors.forename: Shungeng
authors.initials: S
authors.lastname: Min
authors.affiliation: Beijing Research Center for Agricultural Standards and Testing, Beijing 100097, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Ping
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China.
authors.forename: Xiangzhong
authors.initials: X
authors.lastname: Song
mesh_terms: D000818:Animals; D002417:Cattle; D004952:Esters / Q000032:analysis*; D005260:Female; D005504:Food Analysis / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D057230:Limit of Detection; D059627:Liquid Phase Microextraction; D008892:Milk / Q000737:chemistry*; D010795:Phthalic Acids / Q000737:chemistry; D012997:Solvents / Q000737:chemistry
chemical_list: D004952:Esters; D010795:Phthalic Acids; D012997:Solvents; C032279:phthalic acid
keywords: DSDME; Directly suspended droplet microextraction; Milk; Phthalic acid esters PAEs