DETERMINATION OF THE SEPARATION EFFICIENCY OF SEMIPERMEABLE MEMBRANES USING A 2 SAMPLE LOOP-BASED FLOW-INJECTION SYSTEM

A method for the determination of the transfer through a semipermeable membrane (microporous PTFE tape), based on a two sample loop flow-injection system, was developed. Investigated and reference samples were injected simultaneously and after the diffusion unit the acceptor stream was merged with the stream carrying the reference sample. Quantitative analysis of the fraction of permeated analyte was with only one injection, and as a measure of the fraction of analyte transferred the ratio of the two consecutive signal areas was used. The method was developed for the determination of the separation yield of HCN using an electrochemical detector. The accuracy of the method was verified by the fraction collection method. This simple procedure could be also applied to other separation devices (e.g., dialysis membranes, liquid-liquid extraction) and other measuring techniques (spectrophotometric, atomic absorption spectrometric, etc.).