Copyright © 2007 John Wiley & Sons, Ltd. Biomed. Chromatogr. 22: 254–259 (2008) DOI: 10.1002/bmc 254 C.-W. Pyun et al. ORIGINAL RESEARCH ORIGINAL RESEARCH Copyright © 2007 John Wiley & Sons, Ltd. BIOMEDICAL CHROMATOGRAPHY Biomed. Chromatogr. 22: 254–259 (2008) Published online 15 October 2007 in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/bmc.920 Monitoring of streptomycin and dihydrostreptomycin residual levels in porcine meat press juice and muscle via solid-phase fluorescence immunoassay and confirmatory analysis by liquid chromatography after post-column derivatization Chang-Won Pyun, 1† A. M. Abd El-Aty, 2,3† M. M. M. Hashim, 3 Jae-Han Shim, 4 Si-Kyung Lee, 5 Kang-Duk Choi, 6 Kwan-Ha Park, 7 Ho-Chul Shin 2 * and ChiHo Lee 1 * 1 Department of Food Science and Biotechnology of Animal Resources, Konkuk University, 1 Hwayang-dong, Kwangjin-gu, Seoul 143-701, Republic of Korea 2 Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Kwangjin-gu, Seoul, 143-701, Republic of Korea 3 Department of Pharmacology, Faculty of Veterinary Medicine, Cairo University, 12211-Giza, Egypt 4 Natural Products Chemistry Laboratory, Institute of Agricultural Science and Technology, College of Agriculture and Life Science, Chonnam National University, 300 Yong-Bong Dong, Buk-Ku, Gwangju 500-757, Republic of Korea 5 Department of Applied Biology and Chemistry, Konkuk University, 1 Hwayang-dong, Kwangjin-gu, Seoul, 143-701, Republic of Korea 6 Gyeonggi Regional Research Center (GRRC), Hankyung National University, Gyeonggi, 456-749, Republic of Korea 7 College of Ocean Science and Technology, Kunsan National University, Kunsan 573-701, Republic of Korea Received 3 July 2007; accepted 2 August 2007 ABSTRACT: A solid-phase fluorescence immunoassay (SPFIA) that was primarily developed for detection of antibiotic residues in milk was qualitatively applied for the pre-screening of the residues of aminoglycoside antibiotics, streptomycin and dihydrostreptomycin, in meat press juice. The confirmation of both analytes was performed using a validated method of high- performance liquid chromatography with post-column derivatization. The analytical performance was demonstrated by the ana- lysis of pork meat samples spiked at three concentration levels, ranging from 0.25 to 2.5 ppm for each analyte. In general, the recoveries ranged from 80.4 to 81.5% and from 79.6 to 84.4% for streptomycin and dihydrostreptomycin, respectively, with rela- tive standard deviations lower than 6%. The limits of detection were 0.1 and 0.15 ppm for streptomycin and dihydrostreptomycin, respectively, and the limits of quantification of 0.35 and 0.5 ppm are below the maximum residue limits of Codex, the European Union, and the Korean Food and Drug Administration (ranging from 0.5 to 0.6 ppm). Eight real samples collected from the Seoul area were first monitored using SPFIA, and none of them were found positive. These findings are in good accordance with those observed by HPLC analysis. To the best of our knowledge, this is the first report to monitor the aminoglycoside residues in pork meat press juice using SPFIA. Copyright © 2007 John Wiley & Sons, Ltd. KEYWORDS: aminoglycosides; meat press juice; screening; SPFIA; residue analysis; immunoassay INTRODUCTION Streptomycin (STP) and its derivative dihydrostrepto- mycin (DST) are narrow-spectrum aminoglycoside antibiotics that are particularly active against aerobic Gram-negative bacteria. They primarily act by impairing bacterial protein synthesis through binding to prokaryo- tic ribosomes. Susceptible strains include Actinomyces bovis, Pasturella spp., Escherichia coli, Salmonella spp., Campylobacter fetus, Leptospira spp. and Brucella spp. Mycobacterium tuberculosis is also sensitive (The Merck Veterinary Manual, 1986). When combined with a peni- cillin or tetracycline, the narrow-spectrum aminoglyco- side antibiotics have a wide spectrum of activity and act as broad-spectrum anti-infection formulations for the treatment of bacterial infections in cattle, sheep, pigs and poultry. Among the aminoglycoside antibiotics, streptomycin and dihydrostreptomycin can remain as slowly eliminated antibiotic residues in animal products. *Correspondence to: Ho-Chul Shin, Department of Veterinary Phar- macology and Toxicology, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Kwangjin-gu, Seoul 143-701, Republic of Korea. E-mail: hshin@konkuk.ac.kr ChiHo Lee, Department of Food Science and Biotechnology of Ani- mal Resources, Konkuk University, 1 Hwayang-dong, Kwangjin-gu, Seoul 143-701, Republic of Korea. E-mail: leech@konkuk.ac.kr † These two authors contributed equally to this paper. Abbreviations used: DST, dihydrostreptomycin; KFDA, Korean Food and Drug Administration; MRL, maximum residue limits; NQS, 1,2- naphthoquinone-4-sulfonic acid; SPFIA, solid-phase fluorescence immunoassay; SPS, sodium 1-pentane-sulfonate; STP, streptomycin.