Construction of novel magnetic nanoparticles for enrichment of benzo(α)pyrene from edible oils followed by HPLC determination.

A novel method for benzo(α)pyrene (Bαp) enrichment from an oil matrix was developed by using magnetic nanoparticles (Fe3O4@dopamine/graphene oxide, Fe3O4@DA/GO) as extraction absorbents, and the chemical properties of the synthesized nanoparticles were characterized. Various parameters were investigated to optimize the extraction of Bαp from oils. Under optimal conditions (pH, 4; extraction time, 0.5 min; elution solvent, 1 mL; absorbent weight, 20 mg; elution time, 0.5 min), these nanoparticles showed excellent abilities to enrich Bαp from the saponified oil solution and were easily separated by a magnet. High-performance liquid chromatography plus fluorescence detection (HPLC-FLD) was then applied to determine the Bαp content with excellent linearity (R2 = 0.999). The detection limit was 0.13 µg/kg, while the limit of quantification was 0.42 µg/kg. The spiked recoveries of Bαp in oils ranged from 73.5% to 121%. Compared with previous reports, the proposed method displayed many advantages, including a high efficiency of oil matrix removal, short extraction time, and convenient extraction procedure.

A novel magnetic solid-phase extraction method for detection of 14 heterocyclic aromatic amines by UPLC-MS/MS in meat products.

The current study developed a cheap and effective method for the simultaneous extraction of 14 heterocyclic aromatic amines (HAAs) in food matrix. Core-shell Fe3O4@PDA nanoparticles were constructed and acted as the magnetic solid-phase extraction adsorbent to separate and purify HAAs from meat products for the first time. Then, UPLC-MS/MS technique was employed to identify and quantify the HAAs easily. Fe3O4@PDA nanoparticles were synthesized and characterized successfully. Totally 14 HAAs were completely separated in 19.99 min with good regression coefficients. LODs and LOQs were in the range of 0.013-0.247 ng/g and 0.056-0.803 ng/g, respectively. The intra-day precisions and inter-day precisions were below 9%. Except for IQ[4,5-b], Phe-p-1, PhIP, other 11 types of HAAs (DMIP, 1,5,6-TMIP, IQ, IQx, MeIQ, MeIQx, 7,8-DiMeIQx, AαC, MeAαC, Harman, Norharman) could acquire relatively high recoveries (71.06%-108.49%). The proposed method was successfully devoted to the evaluation of HAAs levels in 8 commercial meat products to verify the adaptability.

Assessment of potential toxicity of foodborne fluorescent nanoparticles from roasted pork.

Foodborne nanoparticles (NPs) refer to the nanostructures generated during food processing, rather than the man-made nano-structural additives that are added to improve the property of food. In this research, discovery of fluorescent NPs in roasted pork was reported at different temperature of 180, 230, and 280 °C. The size of the pork NPs was in the range of 5.93-7.49 nm. The FTIR and XPS analysis showed that the NPs are made up of graphitic carbon (sp2) and carbon defects (sp3), with abundant hydroxyl and carbonyl groups on the surface. The Ussing chamber test clearly showed the pork NPs had permeability passing through intestine. Significant fluorescence quenching of NPs was observed in the digestion in vitro. The bio-distribution of NPs in mice indicated that they obviously presented in liver, kidney and testis, even crossed the blood-brain barrier, entering into the brain. The oral administration of pork NPs at a dose of 2 g/kg mouse body weight did not caused obvious toxicity in BALB/c mice. However, significant influence of the NP exposure was observed on locomotion behaviors and lifespans in wild type Caenorhabditis elegans.