2 August / September 2016 Foreword

Welcome to the third edition of Chromatography Today in 2016. This August – September edition of Chromatography Today focuses on Supercritical Fluid Chromatography (SFC) and Chiral Chromatography Separations.

SFC’s popularity has ebbed and flowed since its first mention at a gas chromatography conference in 1957. Since, the technique has moved from crude packed columns to open tubular columns and now more recently to very high efficiency packed columns. Instrument limitations were historically always cited as being a major hurdle for SFC and even though there has been much progress toward making SFC a mainstream analytical tool it is still considered by many as ‘more complex and difficult than HPLC’.

Progress in SFC has been made in the last 5-10 years, where instrument manufacturers and column packing manufacturers have been large drivers in SFC becoming more popular, with several major instrument companies now sporting an analytical SFC unit in their portfolios and scalable achiral ‘engineered for SFC’ specific columns now being made available. If purification is the end goal, then SFC is the technique of choice both analytically and preparatively with many pharmaceutical companies employing SFC as a green purification technique. It is important therefore that the technique is transferable and scalable.

Compared to the August/September 2014 issue which focused solely on SFC and was a lot more theoretical, the current issue contains articles which focus on more practical solutions in SFC with several new achiral column packing materials being discussed, an article on selecting an achiral column screening kit and several articles on overcoming injection issues in SFC. Including one by our editorial review board member Torgny Forstedt on the root causes of peak distortion in preparative SFC, which includes some new findings and is a precursor article to a presentation by Torgny at the SPICA meeting in Vienna. Maybe this is a sign of the current level of uptake for SFC.

As noted in the helpdesk article in this issue, which deals with how retention time reproducibility affects chiral separations, the manufacturing processes of many of active pharmaceutical ingredients (API’s) can result in racemic mixtures being formed which may differ in efficacy and toxicity. Thalidomide, which was introduced in the 1950’s to relieve morning sickness during pregnancy, is one such compound which resulted in serious birth defects for a period of 10+ years until the root cause was found; that thalidomide contained a toxic racemate.

Trevor Hopkins - Editor

The FDA and EMA have since required manufacturers to identify and characterise each individual isomer of a new racemic API. Chiral chromatography is the technique of choice for this task.

Unfortunately, in chiral chromatography there is currently no universal chiral stationary phase (CSP) (cf. ODS/C18 in HPLC and UHPLC) so the selection of a chiral column is in general based on the expected interaction mechanism between CSP and chiral analyte. There are more than a hundred CSP’s that have been developed [1] in search of the universal CSP including those based on cyclodextrin, amylose and cellulose and their derivatives. Several new CSP’s are described in the chiral focus section with an article from Pfizer, San Diego (USA) describing a set of new chiral phases aimed at fluorinated drug candidates.

I hope you enjoy this edition of Chromatography Today and that you find the content stimulating and relevant. I look forward to seeing you at some of the remaining meetings I will attend this year such as ISC 2016 in Cork, SFC 2016 and SPICA 2016 both in Vienna. A print copy of this issue will be made available to all delegates at all these meetings.

Watch out for the November/December issue of Chromatography Today which will contain features on Sample Preparation (including SPE, SPME & Flash Chromatography) and Large Molecule Separation and Purification.

With best wishes Trevor. REFERENCE

1. Chiral Drugs: An Overview by Lien Ai Nguyen et. al. Int J Biomed Sci. 2006 Jun; 2(2): 85–100

Next Issue - Sample Preparation & Large Molecule Separation and Purification To be included call us on +44(0)1727 855574 or

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