Screening for antioxidants in complex matrices using high performance liquid chromatography with acidic potassium permanganate chemiluminescence detection.

The use of high performance liquid chromatography with acidic potassium permanganate chemiluminescence detection to screen for antioxidants in complex plant-derived samples was evaluated in comparison with two conventional post-column radical scavenging assays (2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(+))). In this approach, acidic potassium permanganate can react with readily oxidisable compounds (potential antioxidants), post-column, to produce chemiluminescence. Using flow injection analysis, experimental parameters that afforded the most suitable permanganate chemiluminescence signal for a range of known antioxidants were studied in a univariate approach.

High-performance liquid chromatography with post-column 2,2'-diphenyl-1-picrylhydrazyl radical scavenging assay: methodological considerations and application to complex samples.

An improved post-column 2,2'-diphenyl-1-picrylhydrazyl (DPPH*) radical scavenging assay for the screening of antioxidants in complex matrices was developed. Experimental parameters believed to be influential to DPPH* response were studied in a univariate approach. Optimum conditions were found to be: 5 x 10(-5) M DPPH* reagent prepared in a 75% methanol: 25% 40 mM citric acid-sodium citrate buffer (pH 6) solution, degassed with nitrogen; reaction coil of 2 m x 0.

Determination of Citrus aurantium protoalkaloids using HPLC with acidic potassium permanganate chemiluminescence detection.

Acidic potassium permanganate chemiluminescence was explored as a sensitive and selective mode of detection for phenolic phenethylamines (adrenergic amines) in consumer products containing Citrus aurantium extracts. Nine commercially available weight-loss products were analysed using rapid reversed-phase chromatography with a monolithic column (separation time of 4 min). The results were in good agreement with package labelling, with some notable exceptions.