Microwave-assisted extraction and high-throughput monolithic-polymer-based micro-solid-phase extraction of organophosphorus, triazole, and organochlorine residues in apple

An In Situ Formation of Ionic Liquid for Enrichment of Triazole Fungicides in Food Applications Followed by HPLC Determination

An in situ formation of ionic liquid was used for preconcentration of four triazole fungicides in food samples. The microextraction method was used for the first time in the literature for preconcentration of triazole fungicides. In the developed method, tributylhexadecylphosphonium bromide ([P₄₄₄₁₂]Br) and potassium hexafluorophosphate (KPF₆) were used for the formation of hydrophobic ionic liquid. After centrifugation, the fine microdroplets were produced in one step, providing the extraction step in a quick and environmentally friendly manner. The functional group of the hydrophobic ionic liquid was investigated using FT-IR. Various extraction parameters were studied and optimized. In the extraction method, 0.01 g of [P₄₄₄₁₂]Br and 0.01 g of KPF₆, centrifugation at 4500 rpm for 10 min were used. The optimized technique provided a good linear range (90-1000 μg L^-1) and high extraction recovery, with a low limit of detection (30-50 μg L^-1). Methods for the proposed in situ formation of ionic liquid were successfully applied to honey, fruit juice, and egg matrices. The recoveries were obtained in a satisfactory range of 62-112%. The results confirmed the suitability of the proposed microextraction method for selective extraction and quantification of triazole fungicides.

Microwave-Based Technique for Fast and Reliable Extraction of Organic Contaminants from Food, with a Special Focus on Hydrocarbon Contaminants

Due to food complexity and the low amount at which contaminants are usually present in food, their analytical determination can be particularly challenging. Conventional sample preparation methods making use of large solvent volumes and involving intensive sample manipulation can lead to sample contamination or losses of analytes. To overcome the disadvantages of conventional sample preparation, many researchers put their efforts toward the development of rapid and environmental-friendly methods, minimizing solvent consumption. In this context, microwave-assisted-extraction (MAE) has obtained, over the last years, increasing attention from analytical chemists and it has been successfully utilized for the extraction of various contaminants from different foods. In the first part of this review, an updated overview of the microwave-based extraction technique used for rapid and efficient extraction of organic contaminants from food is given. The principle of the technique, a description of available instrumentation, optimization of parameters affecting the extraction yield, as well as integrated techniques for further purification/enrichment prior to the analytical determination, are illustrated. In the second part of the review, the latest applications concerning the use of microwave energy for the determination of hydrocarbon contaminants-namely polycyclic aromatic hydrocarbons (PAHs) and mineral oil hydrocarbons (MOH)-are reported and critically overviewed and future trends are delineated.