U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Chen, Guoyingitem
                                            SMITH, EMILY - DREXEL UNIVERSITYitem
                                            QIN, FENG - INST FOOD CONTROL,CHINAitem
                                            Liu, Linshu
  Submitted to: Journal of Agricultural and Food Chemistry
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 3/8/2006
                                    Publication  Date: 3/31/2006
                                    Citation: Chen, G., Smith, E., Qin, F., Liu, L.S. 2006. Time-resolved luminesence screening of antibiotics in tissue matrices without centrifugation and filtration. Journal of Agricultural and Food Chemistry. 54:3225-3230.Interpretive Summary: The presence of antibiotic residues in foods of animal origin is a health concern.  Animal tissues are complex and rich in protein and fat, analysis of trace amount of residues typically requires elaborate extraction, enrichment and cleanup, including laborious centrifugation and filtration.  To simplify sample preparation we carried out extraction, enrichment, cleanup and time-resolved luminescence measurement directly on a small, glass-back sorbent layer.  This method is now successfully applied to antibiotic assay in animal tissue matrices, demonstrated by oxytetracycline screening in catfish muscle at 2 parts per million, the FDA regulatory tolerance level.  With measurement directly performed on sorbent surface centrifugation and filtration becomes unnecessary, throughput is therefore improved and costs saved.  Furthermore, organic solvent is not needed since both extraction and cleanup are performed in water, providing a friendly method for both analysts and the environment.
                                Technical Abstract: Analysis of antibiotic residues in foods of animal origin requires multi-step sample preparation including homogenization, extraction, enrichment and cleanup.  For spectrometric analysis tissue particulates must be excluded by centrifugation and filtration to minimize scattering and attenuation.  We developed earlier a methodology that hyphenates sorbent extraction and solid-matrix time-resolved luminescence (SMTRL). Its application is extended to animal tissues, illustrated by oxytetracycline (OTC) screening in catfish muscle.  After homogenization in an EDTA solution, three 10x6 mm glass-back C18 strips are immersed in the homogenate for 20-min for OTC extraction and enrichment.  Following cleanup by a 3-min water immersion and an gentle water spray, the strips are dipped into a TRL reagent solution and desiccated.  TRL is then measured directly on the sorbent surface.  A good linearity (r2 = 0.9966) was obtained in a 0-4 μg/g OTC range with a typical 10-20% RSD.  To screen OTC at 2 μg/g, the FDA regulatory tolerance level, a threshold was set at mean -3SD, of TRL signals from 15 samples fortified at 2 μg/g.  The results from 33 blind samples included 3 false positives and zero negative.  By eliminating centrifugation and filtration, equipment and labor costs are saved, sample throughput improved, and makes field assay possible using a portable fluorometer.  Since no organic solvent is needed for extraction and cleanup this method is friendly to both analysts and the environment.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov