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In this work, hydrophilic molecularly imprinted nanospheres (MINs) were synthesized via surface imprinting technology and subsequently utilized as dispersant sorbent in matrix solid phase dispersion (MSPD) for the extraction of rhodamine B (RhB) as the illogical food additive dye from different foodstuffs, followed by HPLC analysis. By considering hydrophilicity of target analyte, the sol-gel route was chosen for the preparation of MINs in aqueous media at mild conditions. Most importantly, both synthesis and extraction steps were designed and performed in the line of green chemistry and hazardous waste was eliminated to minimize detrimental impact on the operator health and the environment. The reputable experimental design methodology was adopted to assist the condition optimization of MSPD, which comprehends the significance of the factors and their interactions with the least experimental runs. Under optimized MINs-MSPD-HPLC conditions, the detection limit of RhB was down to 0.14 μg kg−1 and excellent linearity over the wide range of 0.5–10000 μg kg−1 was attained. Furthermore, endogenous RhB was found in the tested food samples with relative standard deviations (RSDs) of ≤4.6%, and satisfactory recoveries were from 83.6 to 96.9%. The simple green MINs-MSPD method holds great potential for determination of trace RhB in complicated solid/semi-solid samples, showing rapidity, accuracy and reliability.

In this work, novel dummy molecularly imprinted polymers (DMIP) with propanamide as a dummy template molecule were prepared based on a green synthesis strategy of less consumption of hazardous/organic reagents and at mild conditions for magnetic solid-phase extraction (MSPE) of acrylamide in biscuit samples, followed by high performance liquid chromatography (HPLC) determination. The resultant DMIP was well characterized by FT-IR, SEM, TEM and VSM, exhibiting uniform nanoscale coreshell structure and good magnetic property in favor of simple rapid separation. Several main variables influencing MSPE efficiency were investigated, including DMIP dosage, sample solution pH, extraction time and desorption solvent; central composite design (CCD) and response surface methodology (RSM) were employed to assist in the MSPE condition optimization with rapidity and reliability. Under optimized conditions, excellent linearity for acrylamide was obtained in the range of 5.0–5000.0 µg kg−1, and low detection and quantification limits were 1.3 µg kg−1 and 4.4 µg kg−1, respectively. The method recoveries at five spiked concentrations were found within 86.0–98.3% with relative standard deviations (RSDs) of 1.2–4.1%. Furthermore, endogenous acrylamide was detected in five different biscuit samples and the RSDs values were lower than 3.3%. The present study suggested promising perspectives of water-compatible eco-friendly DMIP based MSPE-HPLC method for highly effective sample pretreatment and targeted analytes determination in complicated matrices.

This study discusses a novel and simple method for the preparation of magnetic dummy molecularly imprinted nanoparticles (MDMINPs). Firstly, Fe3O4 magnetic nanoparticles (MNPs) were synthesized as a magnetic component. Subsequently, MDMINPs were constructed via the sol-gel strategy using APTMS as the functional monomer. Urethane was considered as dummy template to avoid residual template and TEOS as the cross linker. The prepared MDMINPs were used for the pre-concentration of acrylamide from potato chips. Quantification was carried out by high performance liquid chromatography with UV detection (HPLC-UV). The impact of influential variables such as pH, amount of sorbent, sonication time and eluent volume were well investigated and optimized using a central composite design. The particles had excellent magnetic property and high selectivity to the targeted molecule. In optimized conditions, the recovery ranged from 94.0% to 98.0% with the detection limit of 0.35µgkg(-1).