Determination of ethylenediaminetetra-acetic acid in aqueous rinses of detergent-washed rubber stoppers of pharmaceutical vials using solid-phase extraction and capillary gas chromatography.
A fused silica capillary gas chromatographic method is presented for the determination of traces of ethylenediaminetetra-acetic acid (EDTA) in aqueous rinses of rubber stoppers of pharmaceutical vials after treatment with detergents containing EDTA. Isolation and enrichment of EDTA from the aqueous medium is achieved using a commercially available strong anion-exchange solid-phase extraction cartridge, transformed to the formate form. A 2.0-ml volume of methanolic HCl is used for both elution of EDTA from the extraction column and formation of the tetramethyl ester derivative. With the incorporation of a methanolic wash to eliminate interfering components prior to elution with methanolic HCl, a limit of detection of 25 ng EDTA per ml water with a non-selective flame ionization detector is possible.
Ribick
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MA
Squibb Institute for Medical Research, Analytical R & D Department, P.O. Box 191, New Brunswick, NJ 08903, USA.
Jemal
M
M
Cohen
A I
AI