Separation of Retinol and Retinyl Esters Using a Sub Ambient Temperature Program

Released on = August 23, 2005, 1:07 am

Press Release Author = Selerity Technologies

Industry =

Press Release Summary = Using Selerity Technologies Polaratherm, a sub-ambient temperature programme has proved an effective measure for speed, resolution and peak efficiency in the separation of retinol and retinyl esters

Press Release Body = Typically, a solvent gradient is used to resolve all forms of vitamin A in a single HPLC analysis as the polarity range is large. The Polaratherm Total Temperature Controller from Selerity Technologies Inc (Salt Lake City, Utah) has demonstrated optimised results in the separation of vitamin A in biological samples by using a sub-ambient temperature program.

A new application note is available free of charge from Selerity Technologies to describe the improvements in separation time and performance by using sub-ambient temperatures. The application note is available directly from Selerity Technologies, please request application number 813.

For difficult separations such as retinols and retinyl esters, a sub-ambient temperature program has proven an effective method to achieve more efficient peaks and resolution. Retinyl acetate and retinyl palmitate are both used for food fortification and Vitamin A supplementation. Retinyl acetate does not occur naturally in biological tissues, but is often used as an internal standard in HPLC
analysis of vitamin A because it has the same absorbance characteristics, is inexpensive and readily available. In biological samples, vitamin A exists as the free alcohol (retinol) and its esters with long-chain fatty acids (predominantly retinyl palmitate and retinyl stereate). In most biological tissues, for example liver and kidney, the esters dominate, whereas high ester concentration in plasma is
diagnostic of hypervitaminosis A.

One separation was done at ambient temperature and one was performed using a sub-ambient temperature program. The temperature program was started at 0oC, holding for one minute, ramping to 35oC over six minutes, holding for 0.1 minutes, then ramping to 45oC over ten minutes, and holding at 45oC until the
end of the run. Using the temperature program, a 60% reduction in analysis time and much sharper peaks for all analytes were attained.

Selerity’s Polaratherm is a HPLC column compartment capable of controlling the temperature from sub zero to 200ºC benefiting from two modes of operation, temperature programming and isothermal. It is the first column compartment that allows and regulates high, ambient, low or dynamic temperatures for selectivity tuning and improved HPLC separations. This equipment is applicable to most vendor HPLC systems and can be deployed in any laboratory already operating HPLC at little additional cost.

For more information about the Polaratherm or Selerity’s range of TPLC
instrumentation, please visit www.selerity.com or e-mail sales@selerity.com – ENDS – For further press information please contact: Wendy Bow, The Scott Partnership, The Old Barn, Holly House Estate, CRANAGE, Middlewich, Cheshire CW10 9LT, United Kingdom Tel: + 44 1606 837787 Fax: +44 1606 837757 mail
to:pr@scottmail.co.uk

Web Site = www.selerity.com

Contact Details = Selerity Technologies Inc
2484 West Custer Road
Salt Lake City, UT 84104
801-978-2295
801-978-2298
sales@selerity.com