F. Ortizboyer et al., PHASE DISCRIMINATION IN CONTINUOUS LIQUID-LIQUID-EXTRACTION WITH DIODE-ARRAY PHOTOMETRIC DETECTION, Analytical chemistry, 66(17), 1994, pp. 2794-2798
A high-resolution phase-discrimination approach for use in continuous
liquid-liquid extraction monitoring is reported that uses any availabl
e diode array spectrophotometer to monitor the segmented flow at three
wavelengths: one for discriminating the phases involved, another for
monitoring the target species, and the third for correction of signal
fluctuations. Two sizes of organic-aqueous-phase segmentation are prod
uced along the dynamic system: short segment lengths favoring mass tra
nsfer between the immiscible phases and longer segments formed at the
expense of the shorter ones in a grouping chamber in order to allow on
e of the phases to fully occupy the flow cell path length line during
monitoring. The proposed approach was successfully used for continuous
monitoring of both aqueous and the organic phases, as well as continu
ous liquid-liquid extraction processes involving chemical derivatizati
on reactions.