Separation type: Bridge Ion Separation Technology, or BIST™ by SIELC Technologies

Fluoroacetic acid is a toxic metabolite of some drugs that contain fluorine and is a common ingredient in pesticide production. Difluoroacetic acid (DFA) is typically used as a difluoromethylating reagent. Trifluoroacetic acid (TFA) is a popular reagent in organic syntheses and is a popular ion pairing agent in HPLC for large organic molecules. Both DFA and TFA are far less toxic than Fluoroacetic acid. Using SIELC’s newly introduced BIST™ method, a mixture of these fluoroacetic acids can be separated on a negatively-charged, cation-exchange BIST™ A+ column, contrary to conventional chromatographic wisdom. There are two keys to this retention method: 1) a multi-charged, positive buffer, such as N,N,N’,N’-Tetramethyl-1,3-propanediamine (TMDAP), which acts as a bridge, linking the negatively-charged anion analytes to the negatively-charged column surface and 2) a mobile phase consisting mostly of organic solvent (such as MeCN) to minimize the formation of a solvation layer around the charged analytes. Other positively-charged buffers that can generate BIST™ include Calcium acetate and Magnesium acetate. Using this new and unique analysis method, these anions can be separated, retained, and detected with a Conductivity Detector.

Condition

Column	BIST™ A+, 2.1×100 mm, 3 µm, 100A
Mobile Phase	MeCN – 90%
Buffer	TMDAP ( N,N,N’,N’-Tetramethyl-1,3-diaminopropane) formate – 5 mM pH 4.0
Flow Rate	0.4 ml/min
Detection	Conductivity

Description

Class of Compounds	Acid, Carboxylic acid, Haloacetic acid
Analyzing Compounds	Fluoroacetic acid, Difluoroacetic acid and Trifluoroacetic acid