Rapid determination of ractopamine residues in edible animal products by enzyme-linked immunosorbent assay: development and investigation of matrix effects.
To determine ractopamine residues in animal food products (chicken muscle, pettitoes, pig muscle, and pig liver), we established a rapid direct competitive enzyme-linked immunosorbent assay (ELISA) using a polyclonal antibody generated from ractopamine-linker-BSA. The antibody showed high sensitivity and specificity in phosphate buffer, with an IC(50) of 0.6 ng/mL, and the limit of detection was 0.04 ng/mL. The matrix effect of the samples was easily eliminated by one-step extraction with PBS, without any organic solution or clean-up procedure such as SPE or liquid-liquid extraction, making it a much more simple and rapid method than previously reported ones. The detection limit in blank samples was 0.2 mug/kg. To validate this new RAC (ractopamine hydrochloride) ELISA, a RAC-free pig liver sample spiked at three different concentrations was prepared and analyzed by HPLC and ELISA. The results showed a good correlation between the data of ELISA and HPLC (R(2) > 0.95), which proves that the established ELISA is accurate enough to quantify the residue of RAC in the animal derived foods.
Zhang
Yan
Y
Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China.
Wang
Fengxia
F
Fang
Li
L
Wang
Shuo
S
Fang
Guozhen
G
D000818:Animals; D001709:Biotechnology / Q000379:methods; D002417:Cattle; D002645:Chickens; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005504:Food Analysis / Q000379:methods; D005506:Food Contamination; D006801:Humans; D020128:Inhibitory Concentration 50; D008099:Liver / Q000378:metabolism; D008460:Meat / Q000032:analysis*; D009132:Muscles / Q000378:metabolism; D010627:Phenethylamines / Q000032:analysis*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013552:Swine
D010627:Phenethylamines; D012710:Serum Albumin, Bovine; C060897:ractopamine