Current status and future trends on automated multidimensional separation techniques employing sorbent‐based extraction columns

Abstract

Determination of target analytes present in complex matrices requires a suitable sample preparation approach to efficiently remove the analytes of interest from a medium containing several interferers while at the same time preconcentrating them aiming to improve the output signal detection. Online multidimensional solid‐phase separation techniques have been widely used for the analysis of different contaminants in complex matrices such as food, environmental, and biological samples, among others. These online techniques usually consist of two steps performed in two different columns (extraction and analytical column), the first being employed to extract the analytes of interest from the original medium and the latter to separate them from the interferers. The extraction column in multidimensional techniques presents a relevant role since their variations as building material (usually a tube), sorbent material, modes of application, and so on can significantly influence the extraction success. The main features of such columns are subject of constant research aiming improvements directly related to the performance of the separation techniques that utilize multidimensional analysis. The present review highlights the main features of extraction columns online coupled to chromatographic techniques, inclusive for in‐tube solid‐phase microextraction, online solid phase and turbulent flow, aiming the determination of analytes present at very low concentrations in complex matrices. It will critically describe and discuss some of the most common instrumental set up as well as comments on recent applications of these multidimensional techniques. Besides that, the authors have described some properties and enhancements of the extraction columns that are used as first dimension on these systems, such as type of column material (poly (ether ether ketone), fused silica, stainless steel, and other materials) and the way that the extractive phase is accommodated inside the tubing (filled and open tubular). Practical applications of this approach in fields such as environment, food, and bioanalysis are also presented and discussed.

Online Automated Micro Sample Preparation for High-Performance Liquid Chromatography

“…Several unique phases and technical solutions have been developed to improve extraction efficiency and selectivity when extended to microscale applications Online Automated Micro Sample Preparation for High-Performance Liquid Chromatography DOI: http://dx.doi.org /10.5772/intechopen.89079 [44, [51][52][53]. These include polypyrrole (PPY) coated capillaries; PEEK tube capillaries packed with molecularly imprinted polymer (MIP) particles [54][55][56][57][58][59][60][61]; and highly biocompatible SPME capillaries packed with alkyl-diol-silica (ADS) particles as restricted access media (RAM) [62,63], immunosorbents [64], ionic liquids [65][66][67], monolithic materials [68][69][70][71][72][73], carbon nanomaterials [74][75][76][77][78][79][80][81][82], silica-coated magnetite (SiO 2 -Fe 3 O 4 ) [83][84][85][86], and temperature responsive polymers [87,88].…”

Current Trends in Fully Automated On-Line Analytical Techniques for Beverage Analysis

“…Another alternative to preparing in-tube SPME columns involves the use of filled microcolumns containing a sorbent material in either a particle bed or a monolithic format. Microcolumn drivers may be capillary tubes of fused silica, stainless steel, poly (ether ether ketone) (PEEK) [72] and other hybrid materials like silica-steel tube [63]. The main characteristic of each material varies in its flexibility, mechanical strength, and high pressure and solvent resistance [72].…”

“…Microcolumn drivers may be capillary tubes of fused silica, stainless steel, poly (ether ether ketone) (PEEK) [72] and other hybrid materials like silica-steel tube [63]. The main characteristic of each material varies in its flexibility, mechanical strength, and high pressure and solvent resistance [72]. The sorbent material comprises solid particles with regular or irregular shape, commonly used as SPE or HPLC columns, offering a wide range of commercially available stationary phases and dimensions [72].…”

“…The main characteristic of each material varies in its flexibility, mechanical strength, and high pressure and solvent resistance [72]. The sorbent material comprises solid particles with regular or irregular shape, commonly used as SPE or HPLC columns, offering a wide range of commercially available stationary phases and dimensions [72]. Andrade et al [73] packed C18 spherical particles (dp = 10 µm; 100 Å pore size) in a PEEK tube (50 mm length; 0.508 i.d) showing adequate results for the analysis of ochratoxin A in wine samples.…”

Multidimensional Liquid Chromatography Employing a Graphene Oxide Capillary Column as the First Dimension: Determination of Antidepressant and Antiepileptic Drugs in Urine

“…In order to overcome these shortcomings, modern sample preparation techniques based on the principles of the precursor solid-phase microextraction (SPME) began to appear in the early 1990s [14]. Consequently, the current trends are mainly based on miniaturization, automation, and high-throughput analysis, which point out automated methods that integrate sample preparation and HPLC-MS/MS as a suitable combination [15].…”