A critical evaluation of a flow‐cell based on a liquid core waveguide for chemiluminescence measurements

Abstract

Liquid-core waveguides (LCWs), devices that constrain the emitted radiation minimizing losses during the transport, are an alternative to maximize the amount of detected radiation in luminescence. In this work, the performance of a LCW flow-cell was critically evaluated for chemiluminescence measurements, by using as model the oxidation of luminol by hydrogen peroxide or hypochlorite. An analytical procedure for hypochlorite determination was also developed, with linear response in the range 0.2-3.8 mg/L (2.7-51 micromol/L), a detection limit estimated as 8 microg/L (0.64 micromol/L) at the 99.7% confidence level and luminol consumption of 50 microg/determination. The coefficients of variation were 3.3% and 1.6% for 0.4 and 1.9 mg/L ClO(-), respectively, with a sampling rate of 164 determinations/h. The procedure was applied to the analysis of Dakin's solution samples, yielding results in agreement with those obtained by iodometric titration at the 95% confidence level.

Development of a new procedure for the determination of captopril in pharmaceutical formulations employing chemiluminescence and a multicommuted flow analysis approach

“…Chemiluminescence is a photometric technique that does not require a detection instrument furnished with a monochromator for wavelength selection, thus enabling the development of analytical procedures with cost‐effective instrumentation. Reproducible sample introduction and fast mixing conditions, which might have become a drawback, are accomplished by employing flow injection approach .…”

Microflow‐injection chemiluminescence of luminol and hypochlorite enhanced by phloxine B

“…Due to its highly oxidative properties, hypochlorite is widely used as a sewage disinfection reagent for municipal water and as an industrial bleaching agent. Meanwhile, hypochlorite can also act as a chemiluminescence (CL) oxidant, reacting with luminol or certain luminescent reagents for determining the concentrations of hypochlorite or chlorine , ammonium , catecholamines , isoniazid , folic acid , etamsylate , gabapentin and serum albumin , as well as the antioxidant activity of amino acids . A number of analytical methods have been proposed for the determination of hypochlorite in water samples, including iodometry , spectrophotometry , electroanalysis and chromatography .…”