title: Comparison of in-line connected diode array and electrochemical detectors in the high-performance liquid chromatographic analysis of coenzymes Q(9) and Q(10) in food materials.
abstract: In-line connected electrochemical (EC) and diode array (DAD) detectors were compared in the reversed-phase high-performance liquid chromatographic (RP-HPLC) analysis of coenzymes Q(9) and Q(10) in some food materials (beef steak, beef heart, Baltic herring fillet, and rye flour). Coenzymes Q(9) and Q(10) were extracted from the samples using a 5:1 n-hexane-ethanol mixture. Coefficient of variation (CV%) of quadruplicate or quintuplicate determined samples for coenzymes Q(9) and Q(10) was <10 by both EC detector and DAD. Responses of the detection systems were linear in the range evaluated, 10-200 ng/injection, and had correlation coefficients exceeding 0.999. Recoveries of added coenzymes Q(9) and Q(10) varied 73-105% for DAD and 74-103% for EC detector, respectively. Detection limits for coenzymes Q(9) and Q(10) using the DAD system were 4 and 6 ng/injection, respectively, and 0.2 and 0.3 ng/injection by EC detection. Results derived from the two detection systems were generally similar. However, although EC detector was 20-fold more sensitive, the selectivity was, in some cases, poorer than that of DAD.
authors.affiliation: Agricultural Research Centre of Finland, Food Research, L-talo, 31600 Jokioinen, Finland. pirjo.mattila@mtt.fi
authors.forename: P
authors.initials: P
authors.lastname: Mattila
authors.forename: M
authors.initials: M
authors.lastname: Lehtonen
authors.forename: J
authors.initials: J
authors.lastname: Kumpulainen
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003067:Coenzymes; D004563:Electrochemistry / Q000379:methods; D005399:Fishes; D005433:Flour / Q000032:analysis; D005504:Food Analysis; D008460:Meat / Q000032:analysis*; D012434:Secale; D013552:Swine; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000032:analysis*
chemical_list: D003067:Coenzymes; D014451:Ubiquinone; C024989:coenzyme Q10; C030571:ubiquinone 9