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

Abstract

We have examined a range of new and previously described flow cells for chemiluminescence detection. The reactions of acidic potassium permanganate with morphine and amoxicillin were used as model systems representing the many fast chemiluminescence reactions between oxidising agents and organic analytes, and the preliminary partial reduction of the reagent was exploited to further increase the rates of reaction. The comparison was then extended to high-performance liquid chromatography separations of α- and β-adrenergic agonists, with permanganate chemiluminescence detection. Flow cells constructed by machining novel channel designs into white polymer materials (sealed with transparent films or plates) have enabled improvements in mixing efficiency and overall transmission of light to the photodetector.

Recent advances in flow injection analysis

“…In comparative studies of numerous types of construction of such flow cells, it was concluded that construction based on a coil of polymer tubing is an effective approach. 265 Recorded signals can be improved with use of a reflective backing plate, but when a cell is fabricated from a Teflon disk with machined serpentine channel, the signal can be improved by the introduction of glass microspheres in the Teflon disk in order to improve the transmission of light to the PMT. To provide an efficient mixing of reacting solutions, pulsed flow chemistry manifolds with a special module were developed, where short pressure pulses were used to generate bursts of solution flow for immediate mixing in front of the detector.…”

Active bioparticle manipulation in microfluidic systems

“…DNA sequencing refers to the precise determination of nucleotides order within a DNA molecule. [202][203][204][205][206] In this method an optical hot spot functions as an optical tweezer is used to control DNA translocational velocities. DNA translocations are generated by activation and deactivation of the plasmonic fields.…”

Toward Complete Miniaturisation of Flow Injection Analysis Systems: Microfluidic Enhancement of Chemiluminescent Detection

“…Given the fast chemiluminescent reaction time scales, the process is typically diffusion-limited due to the absence of turbulent mixing vortices in the typical low Reynolds number laminar flow conditions of a FIA system, and thus micromixing is an important consideration not only to increase reaction yield (in this case, the intensity of the chemiluminescent signal) and hence allow lower limits of detection with a given sensor, but also to attain sufficiently short residence times that, in turn, facilitate scale down in the dimensions of the reaction chamber. In view of their relative simplicity, passive sample-reagent mixing strategies, such as the incorporation of serpentine channels and flow obstructions, for example, have therefore been adopted in many FIA-CL platforms to increase the rate of reaction despite their lower mixing efficiencies, − longer residence times, larger associated pressure drops and fabrication complexities compared to their active counterparts. This has primarily been due to the lack of a low cost and efficient active micromixing scheme that can be easily integrated to date, especially if portability is desired.…”