From past few decades, one of the main objectives of analytical and bioanalytical chemistry is the implementation of miniaturized analytical methodologies along with the fundamental aspects of green analytical chemistry. The term miniaturization implies the production of systems with reduced size as compared to conventional systems [1]. In analytical chemistry, the word miniaturization is referred to each step of the analytical process, including sample preparation, analytical separation and detection, with the purpose to reduce the amounts of sample, reagents and solvents, and generated waste. In addition, the miniaturization of analytical systems is generally linked to other challenges in analytical chemistry, such as portability, automation and greening of analytical procedures. Unique features as economy, rapidity, improved analytical performance characterize the miniaturization of analytical systems. Trying to follow the guidelines of the "green concept", the fundamental objectives of sustainable miniaturized analytical systems include elimination of harmful chemicals, introduction of environmental friendly solvents, waste reduction, decrease in costs and energy requirements [2]. Sample preparation is one of the crucial steps of the analytical process, especially when dealing with the determination of the analytes in complex samples. Nowadays, instead of the established extraction techniques, several innovative approaches are being applied which offer several advantages, such as higher extraction efficiency, less time requirements and reduced chemicals consumption. These modern techniques are mainly based on the miniaturization of basic extraction modes. They are generally called microextraction techniques that result as faster, cheaper, easier and more environmentally friendly with respect to the conventional extraction procedures. In addition, the use of alternative solvents such as subcritical water, supercritical fluid, ionic liquids, deep eutectic liquids, instead of hazardous organic solvents has led to miniaturized extraction procedures that can be best adapted to meet the principles of green analytical chemistry [3]. In a few decades, analytical separation has also undergone a process of miniaturization. Since that capillary gas chromatography (GC) has emerged, the development of miniaturized liquid chromatography (capillary and nano-LC) technique to provide comparable speed, efficiency, and sensitivity has been pursued [4]. Miniaturized LC can offer higher analysis efficiency resulting in higher chromatographic resolution and overall sensitivity than conventional LC. Major advantages are related to the reduction of column i.d. and by this means the decrease on the consumption of both mobile and stationary phases. This feature is eco-friendly, in the green chemistry context, because it promotes reductions in both solvent consumption and waste from the analysis. The flow rate reduction allows using additives that are more expensive in the mobile phases (chiral additives for example) thus maintaining lower the analysis cost. Moreover, the low flow rate produces a high compatibility between miniaturized LC and MS, providing higher ionization efficiency and improving the system sensitivity, when compared to conventional LC-MS. In this presentation, an overview of the fundamental aspects and advances over microextraction procedures and miniaturized chromatographic techniques is presented showing miniaturized analytical methods for the determination of bioactive compounds in food and plant matrices.
Miniaturization as one of the trends in Modern Analytical Chemistry
Zeineb Aturki
2022
Abstract
From past few decades, one of the main objectives of analytical and bioanalytical chemistry is the implementation of miniaturized analytical methodologies along with the fundamental aspects of green analytical chemistry. The term miniaturization implies the production of systems with reduced size as compared to conventional systems [1]. In analytical chemistry, the word miniaturization is referred to each step of the analytical process, including sample preparation, analytical separation and detection, with the purpose to reduce the amounts of sample, reagents and solvents, and generated waste. In addition, the miniaturization of analytical systems is generally linked to other challenges in analytical chemistry, such as portability, automation and greening of analytical procedures. Unique features as economy, rapidity, improved analytical performance characterize the miniaturization of analytical systems. Trying to follow the guidelines of the "green concept", the fundamental objectives of sustainable miniaturized analytical systems include elimination of harmful chemicals, introduction of environmental friendly solvents, waste reduction, decrease in costs and energy requirements [2]. Sample preparation is one of the crucial steps of the analytical process, especially when dealing with the determination of the analytes in complex samples. Nowadays, instead of the established extraction techniques, several innovative approaches are being applied which offer several advantages, such as higher extraction efficiency, less time requirements and reduced chemicals consumption. These modern techniques are mainly based on the miniaturization of basic extraction modes. They are generally called microextraction techniques that result as faster, cheaper, easier and more environmentally friendly with respect to the conventional extraction procedures. In addition, the use of alternative solvents such as subcritical water, supercritical fluid, ionic liquids, deep eutectic liquids, instead of hazardous organic solvents has led to miniaturized extraction procedures that can be best adapted to meet the principles of green analytical chemistry [3]. In a few decades, analytical separation has also undergone a process of miniaturization. Since that capillary gas chromatography (GC) has emerged, the development of miniaturized liquid chromatography (capillary and nano-LC) technique to provide comparable speed, efficiency, and sensitivity has been pursued [4]. Miniaturized LC can offer higher analysis efficiency resulting in higher chromatographic resolution and overall sensitivity than conventional LC. Major advantages are related to the reduction of column i.d. and by this means the decrease on the consumption of both mobile and stationary phases. This feature is eco-friendly, in the green chemistry context, because it promotes reductions in both solvent consumption and waste from the analysis. The flow rate reduction allows using additives that are more expensive in the mobile phases (chiral additives for example) thus maintaining lower the analysis cost. Moreover, the low flow rate produces a high compatibility between miniaturized LC and MS, providing higher ionization efficiency and improving the system sensitivity, when compared to conventional LC-MS. In this presentation, an overview of the fundamental aspects and advances over microextraction procedures and miniaturized chromatographic techniques is presented showing miniaturized analytical methods for the determination of bioactive compounds in food and plant matrices.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
