FIA and the Future -
On the drawing board, or already in the prototype stage, the next generation
FIA/SIA systems are emerging. This truly “cutting edge" technology already
has an impact as a “front end” for the following techniques:
ETAAS –for automated analyte preconcentration and matrix removal. Using Bead
Injection technique, the target elements are captured on the Sephadex beads with
ion exchange or other functional groups. Following the capture of the target
species, the beads are moved to another port, connected by a transfer line to a
graphite furnace, into which 20 microliters of beads with the
adsorbed analyte are transferred sandwiched by air segments.
Following water evaporation and ashing, target element is atomized and
measured. An enrichment factor 50 to 100 times is achievable.
Electrospray MS – for automated separation of target biomolecules, furnished
with the biotin “handle’. Using avidin coated Sepharose beads, the target
biomolecules will be captured from a complex mixture selectively, while the
matrix is washed away. Next the beads will be transferred the port
connected to MS port and the avidin-biotin bond will be broken by a suitable
eluent, directing the eluate, via splitter into an electrospray. The protocol
will be optimized by measuring the effectiveness of the separation by monitoring
the translucent beads by UV-VIS or fluorescence spectroscopy.
Capillary Electrophoresis
has an “Achilles' Heel” – the method of sample injection. LAB-ON-VALVE
will automate this step , serving also as a tool for modification of sample and
electrolyte concentration or composition. Automated derivatization of analyte
molecules –such as attachment of a desired fluorescence label is yet another
function that LAB-ON-VALVE system can automatically perform to improve
performance of CE.
While the present research has been focused on
applications of LAB-ON-VALVE to assays based on various spectroscopies,
enhancement of electroanalytical techniques can undoubtedly be achieved as well.