Diphasic dialysis membrane

Direct elimination of proteins and other matrix constituents from food samples can also be accomplished with matrix solid-phase dispersion or diphasic dialysis membrane techniques. A matrix solid-phase dispersion technique was used for the determination of chloramphenicol in meat (66) and milk (67) using... 

Ci8 derivatized silica as the sorbent, while a diphasic dialysis membrane procedure was employed for the isolation of chloramphenicol residues from milk constituents using ethyl acetate as the extraction solvent (68). 

Online dialysis and subsequent trace enrichment has been further described for isolation/purification of flumequine residues from fish muscle (203), or oxolinic acid and flumequine from chicken liver (193) and salmon muscle (204). This involves online purification by diphasic dialysis membrane and trapping of the analytes onto a liquid chromatographic preconcentration column (reversed-phase Ci8 or polymeric), rinsing of the coextracted materials to waste, and finally flushing of die concentrated analytes onto the analytical column. 

Dialysis is a cleanup method in which the analyte passes from one solution to another through a membrane while impurities do not transfer. The process can be set up to remove either low-molecular-weight or high-molecular-weight interferences. As examples, dialysis was used to extract the mycotoxin patulin from apple juice using ethyl acetate in a diphasic system, and to remove... 

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