Yeoun Suk Suh

Chemiluminescence determination of moxifloxacin in pharmaceutical and biological samples based on its enhancing effect of the luminol–ferricyanide system using a microfluidic chip

A sensitive determination of a synthetic fluoroquinolone antibacterial agent, moxifloxacin (MOX), by an enhanced chemiluminescence (CL) method using a microfluidic chip is described. The microfluidic chip was fabricated by a soft-lithographic procedure using polydimethyl siloxane (PDMS). The fabricated PDMS microfluidic chip had three-inlet microchannels for introducing the sample, chemiluminescent reagent and oxidant, and a 500 µm wide, 250 µm deep and 82 mm long microchannel. An enhanced CL system, luminol-ferricyanide, was adopted to analyze the MOX concentration in a sample solution. CL light was emitted continuously after mixing luminol and ferricyanide in the presence of MOX on the PDMS microfluidic chip. The amount of MOX in the luminol-ferricyanide system influenced the intensity of the CL light. The linear range of MOX concentration was 0.14-55.0 ng/mL with a correlation coefficient of 0.9992. The limit of detection (LOD) and limit of quantification (LOQ) were 0.06 and 0.2 ng/mL respectively. The presented method afforded good reproducibility, with a relative standard deviation (RSD) of 1.05% for 10 ng/mL of MOX, and has been successfully applied for the determination of MOX in pharmaceutical and biological samples.

P1.4.13 Determination of L-Ascorbic Acid by a Chemiluminescence Method using a Metal-MWCNT Immobilized Microfluidic Chip

The determination of L-ascorbic acid (AA) by a high throughput chemiluminescence (CL) method using a metal ion attached multiwalled carbon nanotubes (MWCNTs) immobilized microfluidic chip has been developed. The method is based on enhancing CL intensity of the luminol-hydrogen peroxide system with the immobilized metal-MWCNTs in the microfluidic chip and on the quenching of CL intensity with addition of AA. The effects of pH, concentrations of luminol, hydrogen peroxide and metal ions on the CL intensity were investigated and optimized. The calibration curve for AA was linear over the range of 1.6×10 -8 M to 6.4×10 -7 M, the correction coefficient was 0.98913 and the detection limit was 1.11×10 -9 M.