Review: Microextraction Technique Based New Trends in Food Analysis

Food chemistry is the study and classification of the quality and origin of foods. The identification of definite biomarkers and the determination of residue contaminants such as toxins, pesticides, metals, human and veterinary drugs, which are a very common source of food-borne diseases. The food analysis is continuously demanding the improvement of more robust, sensitive, highly efficient, and economically beneficial analytical approaches to promise the traceability, safety, and quality of foods in the acquiescence with the consumers and legislation demands. The traditional methods have been used at the starting of the 20th century based on wet chemical methods. Now it existing the powerful analytical techniques used in food analysis and safety. This development has led to substantial enhancements in the analytical accuracy, precision, sensitivity, selectivity, thereby mounting the applied range of food applications. In the present decade, microextraction (micro-scale extraction) pays more attention due to its futures such as low consumption of solvent and sample, throughput analysis easy to operate, greener, robotics, and miniaturization, different adsorbents have been used in the microextraction process with unique nature recognized with wide range applications.

Liquid phase microextraction techniques combined with chromatography analysis: a review

Sample pretreatment is the first and the most important step of an analytical procedure. In routine analysis, liquid–liquid microextraction (LLE) is the most widely used sample pre-treatment technique, whose goal is to isolate the target analytes, provide enrichment, with cleanup to lower the chemical noise, and enhance the signal. The use of extensive volumes of hazardous organic solvents and production of large amounts of waste make LLE procedures unsuitable for modern, highly automated laboratories, expensive, and environmentally unfriendly. In the past two decades, liquid-phase microextraction (LPME) was introduced to overcome these drawbacks. Thanks to the need of only a few microliters of extraction solvent, LPME techniques have been widely adopted by the scientific community. The aim of this review is to report on the state-of-the-art LPME techniques used in gas and liquid chromatography. Attention was paid to the classification of the LPME operating modes, to the historical contextualization of LPME applications, and to the advantages of microextraction in methods respecting the value of green analytical chemistry. Technical aspects such as description of methodology selected in method development for routine use, specific variants of LPME developed for complex matrices, derivatization, and enrichment techniques are also discussed.

Impact of presence of excipients in drug analysis in fed-state gastric biorelevant media

In this study, the influence of the presence of excipients in sample preparation and clean-up steps required prior to drug analysis in milk-based media which simulate the in vivo properties of the fed state stomach was investigated. 15 excipients, normally present in solid dosage forms of five APIs tested (atenolol, paracetamol, furosemide, nifedipine and propafenone hydrochloride) were mixed (one at a time) with the active pharmaceutical ingredient of interest either via vortexing, co-grinding or shaking of the physical mixture and dissolved in Fed State Simulated Gastric Fluid (FeSSGF). The objective of the study was the assessment of the extraction efficiency of three protein precipitation protocols (using MeOH, ΑCN and 10% w/v TCA), typically used in drug analysis, in milk-based biorelevant media in the presence of the excipients. The mixing technique, fat content of the medium and excipient and solvent effects were investigated. The efficiency of three different protein precipitation reagents in drug extraction when dissolved as API:excipient mixtures in the fed-state medium was compared against the equivalent drug amount recovered in the absence of the excipient in FeSSGF. Most excipients had a significant negative effect (p < 0.05) on drug recovery in the milk-based medium as indicated by the multiple linear regression (MLR) analysis performed. For magnesium stearate and HPMC, the % recovery values were the lowest in four out of the five drugs studied, with a range of 10-100% depending on the API, mixing technique and protein precipitation protocol selected. The negative excipient-dependent effect was more profound in nifedipine and propafenone hydrochloride, the most lipophilic compounds of the study. Acetonitrile was the most effective extraction reagent for most drugs in the presence of excipients, followed by methanol and 10% w/v trichloroacetic acid. Data analysis also revealed a dependence of the extraction method efficiency on the medium lipid content. Application of the above extraction protocols in commercially available formulations highlighted the need for assessment of the effect of excipients in extraction efficiency, before transferring the method directly to dissolution studies of formulations in milk-based fed gastric media. In conclusion, the presence of excipients and the selection of protein precipitation protocol are parameters which can affect significantly the efficiency of protein precipitation when FeSSGF is used as dissolution medium and need to be taken into consideration when developing a quantitative method based on the above sample clean-up technique.