CEREX for PositivePressure SPE
The new CEREX® System processors for Positive Pressure SPE offer state-of-the-art operation for SPE of individual columns containing sorbent beds of a few milligrams in 1ml tube sizes, up through multi-gram beds in 6 ml tube sizes.
Positive pressure processing of SPE columns exhibits a number of advantages compared to traditional vacuum manifold processing. A major problem with conventional vacuum manifolds occurs as faster flowing columns on the manifold run dry, allowing a free flow path for vacuum through the dry columns, slowing the flow on the remaining columns. This results in additional variation in column processing times, thus contributing to irreproducible analyte recoveries. Also, when running fewer columns than needed to accommodate all manifold ports, open ports must be plugged or switched off to prevent vacuum loss, which otherwise causes insufficient flow through the sample columns.
In contrast to vacuum manifolds, the System-48 and System 96 uses unique, restricted gas ports. These ports cause gas flow control such that even if 95 processing channels are wide open, the remaining single channel will receive appropriate pressure to allow facile processing. This feature provides very uniform flow across all column channels, and eliminates the need for plugs or caps when processing fewer than up to 96 samples. |
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