Determination of 23 phthalate esters in food by solid-phase extraction coupled with gas chromatography-mass spectrometry

Abstract

A method for the simultaneous determination of 23 phthalate esters in food samples by solid-phase extraction coupled with gas chromatography-mass spectrometry (SPE-GC-MS) was developed and evaluated. The samples were extracted with hexane or acetonitrile, and cleaned up with a glass ProElut PSA SPE column. The identification and quantification were performed by GC-MS in selected ion monitoring (SIM) mode. The extraction processes of different foods were investigated. The calibration curves of phthalate esters showed good linearity in the range of 0.05-5 mg/L (0.5-5 mg/L for diisononyl phthalate (DINP), diisodecyl-phthalate (DIDP)) with the correlation coefficients (r) between 0.984 8 and 0.999 6. The limits of detection of phthalate esters in food samples ranged from 0.005 to 0.05 mg/kg (S/N = 3) and the limits of quantification ranged from 0.02 to 0.2 mg/kg (S/N = 10). The average recoveries of 23 analytes spiked in 10 kinds of food matrices ranged from 77% to 112% with the relative standard deviations (RSDs, n = 6) of 4.1%-12.5%. The method is suitable for the determination of 23 phthalate esters simultaneously in foodstuffs with easy operation, high accuracy and precision.

Features of floral odor and nectar in the distylous Luculia pinceana (Rubiaceae) promote compatible pollination by hawkmoths

“…The conditions of MS were as follows: the ion source temperature was 300°C, electron energy was 10 V at full scanning mode, the transmission line temperature was 200°C, and the mass spectrum scanning range was 40-650 amu. Floral scent components were identified by comparing their mass fragmentation with the data from the NIST 2008 mass spectral library (NIST/EPA/NIH Mass Spectral Library, data version NIST 2008, mainly including REPLIB, MAINLIB) and Wiley 6 electronic library (the cutoff match was 75%), referring to scientific literature about floral odor compounds in the Rubiaceae (Li et al, 2016(Li et al, , 2017Zheng et al, 2020), and the description of the chemical compound properties on the chemical book website (http://www.chemicalbook. com).…”