Capillary Electrophoresis

Capillary electrophoresis (CE) is a rapidly growing technique that provides a number of advantages for analysts, including high separation efficiency, short analysis times, low waste generation, and a diverse range of applications. Joining us for a discussion on CE this month is Kevin Altria of GlaxoSmithKline Research & Development.

What are some new developments and recent advances in CE?

Altria: CE instruments have been improved and new models launched recently. These offer improved reliability and performance and will lead to improved uptake in routine laboratories.

Development and commercialization of kits for particular analyses have been useful in simplifying operations and increasing reliability. In particular, the use of double-layer coating systems offers the possibility of vastly improved precision and reproducibility leading to increased confidence in routine analysis.

What areas of application do you think CE users have not yet fully tapped into?

Altria: Simple analysis of metal ions and simple inorganic anions offer very easy analysis by CE with "canned" kits being available from CE equipment vendors and CE consumable suppliers. The methods give good selectivity and rapid results. Sensitivity is adequate for most purposes and no special equipment, skill or knowledge is needed to run the method — this is not the case for ion chromatography which CE competes with in this arena. CE equipment suppliers did not strongly promote these applications so awareness and uptake was limited — they now recognize the potential for CE in this area and have developed appropriate methods and application datasheets.

How has the growth of mass spectrometry (MS) as a detection method affected CE?

Altria: The use of CE–MS has increased somewhat in recent years as MS systems and CE–MS interfaces have improved. It is still very much a niche area for analysis and is unlikely to ever approach the volume of application that HPLC–MS has.

What kind of developments do you see on the horizon for CE?

Altria: Analyte-specific CE equipment will be developed — this is already available for CE analysis of biopharmaceuticals such as proteins and DNA. The systems are dedicated and optimized to specific methods and validated methods and reagents are available. Interestingly there are developments where CE systems are being developed for on-site analysis such as bed-side analysis of clinical samples, analysis of wood processing samples at the production line and similar applications. Multiplex CE instruments (equipment containing a bundle of capillaries) are available that allow considerably increased productivity — these are becoming increasingly popular and hold the potential for improved performance which will enhance their attractiveness further.

How has CE instrumentation improved over past few years and how has this helped the use of CE methods to become more prevalent?

Altria: The development of analyte-specific instruments such as C-IEF (capillary iso-electric focusing) instruments with bespoke reagents and pre-programmed validated methods has made these applications very routine and simple to use. This "black-box" type operation has generated considerable confidence in CE. This has led to methods being transferred onto these platforms and these types of CE methods becoming the methods of first choice. CE instrument suppliers have listened to the "voice of the customer" and have addressed issues with equipment that previously gave operational issues and the reliability of instruments and methods has improved, which again has led to increased confidence and uptake of CE.

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