Development of a solid-phase extraction-enzyme-linked immunosorbent assay for the determination of 17beta-19-nortestosterone levels in antifatigue functional foods.
17beta-19-nortestosterone (17beta-NT) has been illegally used in antifatigue functional foods to promote muscle growth and improve endurance. A rapid and sensitive solid-phase extraction-enzyme-linked immunosorbent assay (SPE-ELISA) method was developed and successfully applied to analyze the levels of 17beta-NT in antifatigue functional foods. A polyclonal antibody against 17beta-NT was produced from rabbits immunized with the 17beta-NT-BSA conjugate, and a competitive direct enzyme-linked immunosorbent assay was developed for the rapid detection of 17beta-NT. The concentration causing 50% inhibition (IC(50)) and the limit of detection (LOD) were found to be 0.08 and 0.0055 ng/mL, respectively; this was better than methods previously reported that had a LOD of 2.4 ng/mL. C(18) cartridges were investigated for use in removing the effects of matrix in foods, and the sample purification protocol was optimized. Using the developed SPE-ELISA method, recoveries of functional food samples were obtained in the range of 71% to 91.5%. Moreover, 2 kinds of antifatigue functional foods were analyzed using the established ELISA and HPLC methods. The correlation coefficient of the results obtained using the 2 methods was greater than 0.98. Thus, the preliminary evaluation of the SPE-ELISA method proved that it is a specific, sensitive, and precise tool that can be used for the practical detection of 17beta-NT in various antifatigue functional food samples.
Zhang
Yan
Y
Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin Univ. of Science and Technology, Tianjin 300457, China.
Pan
Tao
T
Fang
Guozhen
G
Ma
Dongyue
D
Wang
Shuo
S
D000818:Animals; D000906:Antibodies / Q000276:immunology; D000918:Antibody Specificity; D002681:China; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005221:Fatigue / Q000517:prevention & control; D005260:Female; D005503:Food Additives / Q000009:adverse effects / Q000032:analysis* / Q000737:chemistry; D005504:Food Analysis / Q000379:methods*; D055951:Functional Food / Q000032:analysis*; D006241:Haptens; D006735:Horseradish Peroxidase / Q000737:chemistry; D020128:Inhibitory Concentration 50; D007881:Legislation, Food; D057230:Limit of Detection; D009277:Nandrolone / Q000009:adverse effects / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D011817:Rabbits; D012710:Serum Albumin, Bovine / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods*
D000906:Antibodies; D005503:Food Additives; D006241:Haptens; D012710:Serum Albumin, Bovine; D009277:Nandrolone; D006735:Horseradish Peroxidase