Using sweeping micellar electrokinetic chromatography to analyze Δ9-tetrahydrocannabinol and its major metabolites

Applications of Capillary Electrophoresis for the Determination of Cannabinoids in Different Matrices

Cannabinoids, terpenophenolic chemicals found only in cannabis, are primarily responsible for cannabis pharmacologic effects; nearly 150 distinct cannabinoids have been identified thus far. Among these, the main psychoactive molecule, tetrahydrocannabinol (THC), and the non-psychoactive counterpart, cannabidiol (CBD) are distinguishable. In the past decade, a CBD-containing pharmaceutical preparation was approved by Food and Drug Administration (FDA) for the treatment of drug-resistant epileptic seizures in children, and research trials for a variety of additional medical conditions for which CBD has been suggested as a therapy are being conducted. Additionally, the number of "CBD-containing" dietary supplements, largely available online, is increasing rapidly. Consequently, the necessity for the development of qualitative and quantitative methodologies for the analysis of the bioactive components of Cannabis is rising because of the increase in the production of therapeutic cannabis products. One of the analytical methods with good potential in cannabinoids analysis is capillary electrophoresis (CE). It has advantages related to high separation efficiency, relatively short analysis time, and the small consumption of analytes and reagents which generates relatively lower operational costs than other methods. This review focuses on the use of CE techniques to examine biological matrices and plant materials for the presence of cannabinoids and other bioactive compounds found in cannabis. The advantages, drawbacks, and applicability of the various electromigration approaches are also assessed. The article provides an overview of the "state of the art" and the latest trends in CE-based methods for the determination of cannabinoids.

Recent methodological and instrumental development in MEKC

The review gives an update about the methodological and instrumental developments in micellar electrokinetic capillary chromatography as a type of CE analytical technique. Here, the last two years development of the technique are particularly presented. Recent approaches to improve sensitivity are discussed. Newly introduced concentration techniques and experimental methods for verification of the different mechanisms and processes of micellar electrokinetic chromatography analysis are highlighted. A theoretical model to explain changes in separation and electrophoretic mobility order of fully charged analytes are demonstrated. Modern approaches for improving compatibility of micellar electrokinetic capillary chromatography to mass spectrometry are also reported.

Review of recent developments of on-line sample stacking techniques and their application in capillary electrophoresis

Capillary electrophoresis (CE) has become one of the most useful tools in separation science because of its high separation efficiency, low cost, versatility, ease of sample preparation and automation. However, some limitations of CE, such as poor concentration sensitivity due to its lower sample loading and shorter optical path length, limits its further applications in separation science. In order to solve this problem, various on-line sample preconcentration techniques such as transient isotachophoresis preconcentration, field-enhanced sample stacking, micelle to solvent stacking, micelle collapse, dynamic pH junction, sweeping, solid phase extraction, single drop microextraction and liquid phase microextraction have been combined with CE. Recent developments, applications and some variants together with different combinations of these techniques integrating in CE are reviewed here and our discussions will be confined to the past three years (2008–2011).

MEKC as a powerful growing analytical technique

This review summarizes the principle and the developments in MEKC in terms of separation power, sensitivity, and detection approaches more than 25 years after its appearance. Newly used surfactants are mentioned. Classical and new sample concentration techniques in MEKC are described. The different detection approaches in MEKC with advantages, limitations, and future prospects are also discussed. This review highlights the wider application of MEKC in different analytical fields. Various recent selected applications of this technique in different analytical fields are reported.

Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips (2008-2010)

Capillary electrophoresis has been alive for over two decades now; yet, its sensitivity is still regarded as being inferior to that of more traditional methods of separation such as HPLC. As such, it is unsurprising that overcoming this issue still generates much scientific interest. This review continues to update this series of reviews, first published in Electrophoresis in 2007, with an update published in 2009 and covers material published through to June 2010. It includes developments in the fields of stacking, covering all methods from field-amplified sample stacking and large volume sample stacking, through to ITP, dynamic pH junction and sweeping. Attention is also given to on-line or in-line extraction methods that have been used for electrophoresis.