55 research outputs found
Rapid Determination of Nine Acrylates in Food Contact Materials by Ultra Performance Convergence Chromatography
Ultra performance convergence chromatography (UPC2) was used to establish a rapid analytical method to determine nine acrylate compounds in plastic food contact materials simultaneously. The samples were extracted with methanol, filtered through an organic membrane, and separated on an ACQUITY UPC2 HSS C18 SB column with gradient elution using a mobile phase consisting of supercritical carbon dioxide and acetonitrile. The photodiode array (PDA) detector was set at 210 nm. Experimental results showed that under the optimal conditions (column temperature, 40 β; and back pressure, 13.79 MPa), qualitative and quantitative analysis of the nine acrylates was completed within 4 min. Linear ranges were 0.2β100 mg/L for phenyl methacrylate (PNMA), benzyl methacrylate (BZMA) and ethylene dimethacrylate (EDMA); 0.3β100 mg/L for methacrylic acid (MAA); 0.4β100 mg/L for butyl acrylate (BTA), hydroxyethyl methylacrylate (HEMA) and hydroxyethyl acrylate (HEA); and 0.5β100 mg/L for isobutylmeth acrylate (IBMA) and benzyl acrylate (BZA). The determination coefficients (R2) of the standard curves for all acrylates were higher than 0.998 5, and recoveries obtained at high (30 mg/kg), middle (6 mg/kg) and low (0.2, 0.3, 0.4 and 0.5 mg/kg) spiked concentrations ranged from 89.3% to 109.7%, with relative standard deviations of 0.62% to 3.86% (n = 6). The limits of detection (RSN β₯ 3) were 0.05β0.15 mg/kg, and the limits of quantification (RSN β₯ 10) were 0.2β0.5 mg/kg. The proposed method identified the risk of acrylate residues in 30 batches of actual samples
Point centrality of the spatial correlation network.
Point centrality of the spatial correlation network.</p
Reachability matrix of the spatial correlation network.
Reachability matrix of the spatial correlation network.</p
Spatial correlation network of urban innovation in Guangdong.
Spatial correlation network of urban innovation in Guangdong.</p
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