Fabrication of acrylate monolith using photopolymerization: Effect of light intensity on electrochromatographic performance

Abstract

Figure 1 was represented in an unclear format. See below for a larger and better readable version of Figure 1: Figure 1. Influence of light intensity P and irradiation time t (or irradiation energy W) on minimal plate height H min (m) for fluoranthene. C

Electrochromatography on acrylate‐based monolith in cyclic olefin copolymer microchip: A cost‐effective and easy‐to‐use technology

“…The performances of HA‐filled COC microchips for the reversed‐phase separation of six PAH (anthracene, fluoranthene, pyrene, benzo‐a‐anthracene, benzo‐a‐pyrene, and benzo‐k‐fluoranthene) were characterized elsewhere . It was shown that, with a mobile phase containing 70% ACN, the retention factors of solutes were contained between 5.2 and 17.8 and efficiencies ranged from 200 000 to 250 000 plates/m at a linear velocity of 1.6 mm/s for a separation length of 2 cm (the corresponding time analysis was 3.5 min).…”

“…The monolith based on HA and BDDA monomers, was previously used in COC electrochromatographic microchips . The porogenic mixture made of 54% w/w of ACN, 23% w/w of ethanol, and 23% w/w of water, is dissolved in the monomer mixture containing 66.4% w/w of HA and 33.6% w/w of BDDA, with the monomerto porogens ratio equal to 34.5:65.5 w/w.…”

“…Then, the microchip is placed in the 365‐nm illumination system at 2.5 cm from the UV tubes. In this position, the microchip is irradiated with a light intensity of 4.7 mW/cm 2 , which is optimal for the chip used . After an irradiation of 6 min (which corresponds to an energy of 1.9 J/cm 2 ), the monolith present in the reservoirs is scraped away.…”

“…Inexpensive and rapid technologies such as hot embossing and injection molding can be used to mass produce microsystems that could be single‐used to eliminate the cross‐contamination and sample carryover problems arising from multiple uses of the same system. Some studies deal with the development of COC electrochromatographic microchips using photopatterned acrylate‐based monolithic stationary phases . We showed that wall ruggedness was sufficient to hold a nonanchored monolith in a COC device used in EC without pressure, but separation efficiency remains poor (about 70 000 plates/m) .…”

“…Anchoring of acrylate monolith inside the COC microchip channel performed by either UV‐grafting before monolith synthesis (two‐steps method) or increasing the photoinitiator concentration in the polymerization mixture (one‐step method) , allows improvement of electrochromatographic efficiency (up to 120 000 plates/m). The achievement of efficiencies as high as the ones obtained in glass microchips for neutral solutes (200 000 plates/m for PAH for example) requires the optimization of light intensity during photopolymerization .…”