@article{oai:nagasaki-u.repo.nii.ac.jp:00002544,
 author = {Fukuda, Mizuho and El-Maghrabey, Mahmoud H. and Kishikawa, Naoya and Ikemoto, Kazuto and Kuroda, Naotaka},
 journal = {Journal of Pharmaceutical and Biomedical Analysis},
 month = {Oct},
 note = {A fast, accurate, and ultrasensitive high-performance liquid chromatography method with chemiluminescence detection (HPLC-CL) was optimized and validated for the determination of pyrroloquinoline quinone (PQQ) concentration in human plasma following solid-phase extraction (SPE). This method is based on the redox cycle of the reaction between PQQ and dithiothreitol, which generates reactive oxygen species that can be detected using luminol as a CL probe. The isocratic HPLC system comprised an ODS column and 4.0 mM tetra-n-butylammonium bromide in Tris-HNO3 buffer (pH 8.8; 50 mM)-acetonitrile (7:3, v/v) as mobile phase. A novel, rapid, and simple SPE method was also developed providing excellent %recovery (?95.2%) for PQQ from human plasma samples. The proposed method was linear over the range of 4.0?400 nmol/L plasma of PQQ with a lower detection limit (S/N=3) of 1.08 nmol/L plasma (0.27 nM). The method was successfully implemented to determine PQQ concentration in the plasma of healthy individuals after administration of PQQ supplements., Journal of Pharmaceutical and Biomedical Analysis, 145, pp.814-820; 2017},
 pages = {814--820},
 title = {Ultrasensitive determination of pyrroloquinoline quinone in human plasma by HPLC with chemiluminescence detection using the redox cycle of quinone},
 volume = {145},
 year = {2017}
}