Analysis of chemical warfare agents (CWAs) and their degradation products is an important verification
component in support of the Chemical Weapons Convention and urgently demanding rapid and reliable
analytical methods. A portable microchip electrophoresis (ME) device with contactless conductivity (CCD)
detection was developed for the in situ identification of CWA and their degradation products. A 10mM
MES/His, 0.4mM CTAB - based separation electrolyte accomplished the analysis of Sarin (GB), Tabun( GA)
and Soman (GD) in less than 1 min, which is the fastest screening of nerve agents achieved with portable ME
and CCD based detection methods to date. Reproducibility of detection was successfully demonstrated on
simultaneous detection of GB (200ppm) and GA (278ppm). Reasonable agreement for the four consecutive runs
was achieved with the mean peak time for Sarin of 29.15s, and the standard error of 0.58s or 2%. GD and GA
were simultaneously detected with their degradation products methylphosphonic acid (MPA), pinacolyl
methylphosphonic acid (PMPA) and O-Ethyl Phosphorocyanidate (GAHP and GAHP1) respectively. The
detection limit for Sarin was around 35ppb. To the best of our knowledge this is the best result achieved in
microchip electrophoresis and contactless conductivity based detection to date.
Droplet-based in vitro compartmentalization (IVC) platform is a powerful tool in protein analysis. Reliable formation of microdroplets is important for the development of the microfluidic chip. In this study, we will examine the effect of surfactants on the formation of microdroplets in the flow focusing microfluidic device which is needed for enzyme evolution. Surfactants of Span 80 and Tween 20 are used in the continuous and dispersed phases, respectively. The droplet formation was affected distinguishably with the presence of Span 80 and Tween 20. The size of droplets decreased as the concentration of Span 80 increased. And the decrease was more pronounced with the combination of Span 80 and Tween 20.