Determination of thyroxine in pharmaceuticals using flow injection with luminol chemiluminescence inhibition detection

Determination of L-thyroxine in pharmaceutical preparations by flow injection analysis with chemiluminescence detection based on the enhancement of the luminol-KMnO4 reaction in a micellar medium

A novel flow injection chemiluminescence (CL) method for the determination of L-thyroxine in the presence of cethyltrimethylammonium bromide (CTMAB) surfactant micelles is developed. The method is based on the significant signal enhancement of L-thyroxine on the luminol-KMnO4 system in alkaline solution sensitized by CTMAB. Parameters affecting the reproducibility and CL detection were optimized systematically. Under the optimum conditions, the net CL intensity versus L-thyroxine concentration was linear in the range of 5.0×10(-8)-3.0×10(-6) mol/L with the detection limit of 8.9×10(-9) mol/L. The sample throughput is calculated to be 140 samples/h and the relative standard deviations (RSDs) for 13 replicate determination of 1.0×10(-6) L-thyroxine is 1.1%. The proposed method was successfully applied for the determination of L-thyroxine in pharmaceutical preparations with satisfactory recoveries in the range of 93.9-105.2%. This rapid, sensitive, and high throughput method would provide a new tool for L-thyroxine analysis.

Luminol chemiluminescence enhanced by copper nanoclusters and its analytical application

It was found that Cu nanoclusters could enhance the chemiluminescence (CL) emission from the luminol–hydrogen peroxide system in an alkaline medium.

Enhanced chemiluminescence of the luminol-hydrogen peroxide system by colloidal cupric oxide nanoparticles as peroxidase mimic

As a peroxidase mimic, cupric oxide nanoparticles were found to enhance the chemiluminescence (CL) of luminol-H(2)O(2) system up to 400 folds. The CL spectra and radical scavengers were conducted to investigate the possible CL enhancement mechanism. It was suggested that the enhanced CL could be attributed to the peroxidase-like activity of CuO nanoparticles, which effectively catalyzed the decomposition of hydrogen peroxide into hydroxyl radicals. The effects of the reactant concentrations and some organic compounds were also investigated. The proposed method could be used as a sensitive detection tool for hydrogen peroxide and glucose.

A rapid and sensitive chemiluminescent immunoassay of total thyroxin with DMAE x NHS-Labeled

A novel chemiluminescence immunoassay (CLIA) of total thyroxin (TT4) with the acridinium ester of DMAE x NHS [2',6'-dimethyl-4'-(n-succinimidyloxycarbonyl) phenyl-10-methyl-acridinium-9-carboxylate methosulfate] labeled has been developed. In our method, microwells were coated with anti-T4 monoclonal antibody (McAb) and DMAE x NHS synthesized by our laboratory was conjugated with streptavidin (SA). T4-BSA was conjugated with biotin-N-hydroxysuccinimide (B x NHS), T4-BSA- B x NHS and the T4 in the standard or sample competitively react with anti-T4 McAb. Streptavidin-biotin separation and enhanced techniques were applied in this assay. The presented approach shows many excellent characteristics, particularly, rapid assay process and high detection sensitivity.