By Laura on Tuesday, September 28, 1999 - 11:11 am:
I am able to retain sodium triphosphate, sodium metasilicate and sodium laureth sulfate on a C18 column using a perfluorinated ion pair reagent. Any suggestions on obtaining a separation would be helpful. I have tried controlling pH, adding organic modifiers, increasing ion pair concentration, and they still elute at the same time. Mobile phase suggestions should be compatible with Evaporative Light Scattering Detection.
I appreciate any help!
By tom on Friday, January 7, 2000 - 04:36 pm:
I have separated these compounds on a C18 column using 0.02% (v/v) nonafluoropentanoic acid (aq.) w/ 5% MeCN, and ELS detection (SEDEX). Sodium nonafluoropentenoate elutes at about 6 minutes. tripolyphosphate and metasilicate are detected as the free acids, are baseline separated, and elute between 2 and 3 minutes. The laureth sulfate (free acid) requires a gradient to higher organic content and eluted as a series of peaks between 7-10 minutes. The sodium peak is verified by injecting Sodium carbonate or bicarbonate. Feel free to contact me via e-mail if you would like at tom@richardscientific.com
By B.Buglio on Tuesday, February 15, 2000 - 05:37 pm:
As an interesting alternative these 3 anions can
be well separated by capillary ion electrophoresis
in about 7 min and are seen easily at the 1-10ppm
level.
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