Analysis of vitamin A isomers (trans and cis retinol)
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By Anonymous on Thursday, June 10, 2004 - 12:12 am:

If anybody could assist I would appreciate it. I need to separate cis-retinol and trans-retanol on a C18 column. All the info I have explored thus far refers to using a normal phase column to separate the isomers of vitamin A. Large pore C18 silicas do not exclude long rigid molecules such as vitamin A, therefor they(C18 phases 300A)should provide better selectivity. My question relates to what column to use. I am curently using a Agilent 1100 HPLC

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By A.Mouse on Thursday, June 10, 2004 - 06:55 pm:

Klaus Albert of Germany has written publications on similar separation problems. Check his references!

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By SUNIL on Thursday, June 10, 2004 - 10:13 pm:

USE INERTSIL C18 250 X 4.6 5u AND TRY 100% ACN AS MOBILE PHASE AND SELECT THE WAVELENTH(I DONT REMEMBER EAXCTLY) BY SCANNING IN THE RANGE OF 200-400 NM. kEEP FLOW RATE AS 1.0 ML/MIN. SAMPLE PREPARATION:INITIAL SAMPLE PREPARATION CAN BE MADE IN CHLOROFORM AND THE FINAL DILUTION CAN BE MADE IN ACN. HOPE U'LL GET IT

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By SUNIL on Thursday, June 10, 2004 - 10:14 pm:

U CAN ALSO USE PRODIGY C18 250 X 4.6 5 u. IF THE SEPARATION IS ADEQUATE U CAN ALSO SHIFT TO 150 X 4.6 5 u