Enrichment in LPME

A great advantage of LPME is the large enrichment factor that can be reached. The acceptor phase has a typical volume varying from 2 to 30 pi. The volume of the donor phase can vary from as low as 50 pi to much more than 11. This makes it possible to achieve considerable enrichment of the analyte in the acceptor phase. In case of a 20 pi acceptor phase and a 20 ml donor phase, the enrichment can theoretically be up to 1000 times (with maximal recovery). 

This not only means that much lower detection limits can be reached but it also implies that with low recoveries, still good extractions can be performed. In case of 5% recovery and an enrichment factor of 1000, the acceptor phase still contains 20 times higher concentration of the analyte than the donor phase. 

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