Study on Migration of Two Triazine Type Ultraviolet Absorbents from Polypropylene Packaging Materials to Food Simulant

The migration rules of two triazine type of UV absorbents (UV-1577 and UV-1579) from polypropylene (PP) food contact materials to food simulant were investigated. A rapid detection method of UV-1577 and UV-1579 in PP food contact materials was established by ultra-performance convergence chromatography (UPC2). The optimal extraction method of the initial solution was determined, and the pretreatment methods of two UV absorbents in the liquid simulants were optimized. Experiment results showed that the interaction effects between the two UV absorbers and the liquid simulants were weak, and the migration behavior was the most obvious in the fatty simulant of isooctane. At the same temperature, the migration amount of both UV-1577 and UV-1579 increased with the extension of time, and UV-1577 was more prone to migration than UV-1579. Within a certain range, the migration amount of the two UV absorbents increased significantly with the increase of the migration temperature. The higher the temperature was, the shorter the time required to reach the equilibrium

Determination of 12 acrylate compounds in plastic food contact materials via high performance liquid chromatography

A high performance liquid chromatography (HPLC) method was used to determine 12 acrylate compounds in plastic food contact materials. The plastic food contact material samples were extracted by ultrasonic with methanol. The mixed solution of water and acetonitrile was used as mobile phase for gradient elution. The samples were separated by ZORBAX SB-AQ column (250 mm×4.6 mm, 5 μm), and analyzed by diode array detector (DAD). The results showed that under the optimal chromatographic conditions, the 12 acrylate compounds had good linear relationships in the range of 0.01-10.0 mg/L, the correlation coefficient of the standard curves were higher than 0.999, and the detection limits (LODs) were 0.03-0.08 mg/kg. The recovery rate was between 85.4% and 110.7%, and the relative standard deviation was from 1.6% to 5.2%. The method was simple and accurate, and can be used for the analysis and detection of 12 acrylate compounds in plastic food contact materials

Determination of two acrylates in environmental water by high performance liquid chromatography

A high performance liquid chromatography (HPLC) method was established for the determination of two acrylate substances in environmental water. The optimal chromatographic conditions were determined via exploring the effects of chromatographic column, mobile phase, column temperature, flow rate, detection wavelength and other factors on the separation effect of acrylate substances. Finally, the effective separation of methyl methacrylate and isopropyl methacrylate was realized within 6 min. The retention time of the target compound was used for qualitative analysis and the external standard method was used for quantitative analysis in the experiment. The linear relationship between the two acrylates was good in the range of 0.2-50.0 mg/L, and the correlation coefficient of standard curve was higher than 0.999. The recovery rate was 88.6%-105.3%, the relative standard deviation was 1.7%-4.1%, and the detection limit (LODs) was 0.03-0.05 mg/L. The method was simple, efficient and accurate, and suitable for the determination of acrylates in environmental water samples

Highly Efficient Adsorption Characteristics and Mechanism of Nutshell Biochars for Aromatic Organophosphorus Insecticides

The wide use of the insecticide profenofos in crop production has led to serious ecological water problems in agricultural fields. With the increasing global production of nuts, a large amount of nutshell waste has a serious impact on the environment. Turning nutshell waste into biochar to remove high levels of profenofos in water is a cost-effective treatment method. In this study, biochars made from nutshell waste are investigated for the adsorption of aromatic organophosphorus insecticide profenofos. The adsorption amount of nutshell biochar was 13-fold higher than crop stalk biochar in removing profenofos from water. The results indicated that the adsorption of profenofos by nutshell biochar was specific. Scanning electron microscope (SEM) and Brunauer–Emmett–Teller (BET) analysis showed that nutshell biochars had a larger specific surface area and more microporous structures. Meanwhile, nutshell biochars could exhibit a stable adsorption capacity at different initial concentrations of profenofos (10–40 mg/L), temperature (298–318 K), and pH (3–7). Desorption and reuse experiments showed that profenofos was firmly bound to nutshell biochars in water and could be extracted from the biochars with acetonitrile. Within 10 times of recycling, nutshell biochar had a stable and strong adsorption capacity for profenofos. The adsorption process of profenofos by nutshell biochar was pore diffusion and surface adsorption, which is consistent with the pseudo second-order kinetic model and the Freundlich isotherm model. Elemental and Fourier transform infrared spectroscopy (FTIR) analyses showed that the adsorption mechanism of profenofos on nutshell biochar was mainly through π-π and hydrophobic interactions. Nutshell biochar also showed strong adsorption capacity for other aromatic organophosphorus pesticides, and the adsorption rates of methyl parathion, isocarbophos and 2-chloro-4-bromophenol were 85%, 73% and 73%, respectively. Nutshell biochar can serve as an excellent material for removing aromatic organophosphorus insecticide pollution from water