Precision milled flow-cells for chemiluminescence detection

Abstract

Novel flow-cells with integrated confluence points and reaction channels designed for efficient mixing of fast chemiluminescence systems were constructed by machining opposing sides of a polymer chip and sealing the channels with transparent epoxy-acetate films. A hole drilled through the chip provided the conduit from the confluence point on one side to the centre of the reaction zone on the other side, allowing rapid presentation of the reacting mixture to the photodetector. The effectiveness of each flow-cell was evaluated by comparing the chemiluminescence intensity using flow injection analysis methodology, and examining the distribution of light emanating from the reaction zone (captured by photography in a dark room) when the reactants were continuously merged. Although previously reported chemiluminescence detectors constructed by machining channels into polymers have almost exclusively been prepared using transparent materials, we obtained far greater emission intensities using an opaque white chip with a thin transparent seal, which minimised the loss of light through surfaces not exposed to the photomultiplier tube. Furthermore, this approach enabled the exploration of reactor designs that could not be incorporated in traditional coiled-tubing flow-cells.

Chemiluminescence detection flow cells for flow injection analysis and high-performance liquid chromatography

“…Flow cell C was constructed by machining channels (0.7× 0.7 mm) into both faces of a polycarbonate chip (46×57×6 mm) and sealing the channels with a transparent epoxy-acetate film [20,28]. The front face contained a serpentine channel configuration, with a central entrance located above the confluence point on the back face ( Fig.…”

“…For his research in these areas, he has received a Victoria Young Tall Poppy Science Award (Australian Institute of Policy and Science), the Robert Cattrall Medal (Royal Australian Chemical Institute) and the Gordon F. Kirkbright Award (Association of British Spectroscopists). machining channels into polymer materials has enabled exploration of designs that are not accessible using the traditional coiled-tubing approach [12][13][14][15][16][17][18][19][20][21]. Studies by our research group and others have shown: (1) repeated changes in the direction of solution flow (such as reversing turns) enhances the mixing efficiency and therefore the emission intensity [12,19,20,22].…”

“…(2) Relatively large chambers or wells in the detection zone generally delay the onset of the maximum emission as the solution rapidly moves through the path of least resistance, leaving surrounding areas of poor solution mixing [19,21]. (3) Channels machined or etched into an opaque white polymer and sealed with a thin piece of transparent material minimise the loss of light through surfaces not exposed to the photodetector [17,20,23]. (4) A mixing tube/channel prior to the entrance of the detection zone is normally required for the reacting mixture to reach maximum emission intensity in front of the photodetector [12,19,24], but in the case of very rapid chemiluminescence systems, merging the solutions within the detection zone may be superior [21].…”

“…machining channels into polymer materials has enabled exploration of designs that are not accessible using the traditional coiled-tubing approach [12][13][14][15][16][17][18][19][20][21]. Studies by our research group and others have shown: (1) repeated changes in the direction of solution flow (such as reversing turns) enhances the mixing efficiency and therefore the emission intensity [12,19,20,22]. (2) Relatively large chambers or wells in the detection zone generally delay the onset of the maximum emission as the solution rapidly moves through the path of least resistance, leaving surrounding areas of poor solution mixing [19,21].…”

Determination of Sulfide with Acidic Permanganate Chemiluminescence for Development of Deep-sea in-situ Analyzers

“…24 The effects of these factors on the CL cell are shown in Table 2. The mixing position was studied using a Pyrex spiral cell.…”