Poly(ethylene glycol) functionalization of monolithic poly(divinyl benzene) for improved miniaturized solid phase extraction of protein-rich samples.

Non-specific protein adsorption on hydrophobic solid phase extraction (SPE) adsorbents can reduce the efficacy of purification. To improve sample clean-up, poly(divinyl benzene) (PDVB) monoliths grafted with hydrophilic polyethylene glycol methacrylate (PEGMA) were developed. Residual vinyl groups (RVGs) of the PDVB were employed as anchor points for PEGMA grafting.

Characterization of large surface area polymer monoliths and their utility for rapid, selective solid phase extraction for improved sample clean up.

While polymer monoliths are widely described for solid phase extraction (SPE), appropriate characterization is rarely provided to unravel the links between physical characteristics and observed advantages and disadvantages. Two known approaches to fabricate large surface area polymer monoliths with a bimodal pore structure were investigated. The first incorporated a high percentage of divinyl benzene (PDVB) and the second explored hypercrosslinking of pre-formed monoliths.

A simplified approach to direct SPE-MS.

Microextraction by packed sorbent (MEPS) has been directly hyphenated with ESI-MS for the rapid screening of opiates and codeine metabolites in urine. This study introduces a novel format of MEPS that incorporates a two-way valve in the barrel of the syringe enabling the direction of liquid flow to be manipulated. Controlled directional flow (CDF) MEPS allows sharp, concentrated sample bands to be delivered directly to the MS in small volumes and effectively eliminates the need to optimize elution.

Dry film microchips for miniaturised separations.

In this work microfluidic devices were made from the dry film photoresist Ordyl SY330, characterised by optical and electron microscopy and used for electrophoretic separations. A simple and fast microfabrication process was developed for the fabrication of channels that are 50 microm wide and 30 microm in height, requiring only the use of an office laminator, a hot plate, an exposure source and mask and an electric drill to make four microdevices in less than 1 h. The optical properties of the photoresist were studied and the resist showed significant absorbance below 370 nm and 570-630 nm, and had an optical transmission of 80% between 400 and 550 nm.