Time-Resolved Luminescence Screening of Antibiotics in Tissue Matrices without Centrifugation and Filtration: Spiked Recovery Studies
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- 作者：Guoying Chen ; Emily Smith ; Feng Qin ; and LinShu Liu
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2006
- 出版时间：May 3, 2006
- 年：2006
- 卷：54
- 期：9
- 页码：3225 - 3230
- 全文大小：240K
- 年卷期：v.54,no.9(May 3, 2006)
- ISSN：1520-5118
文摘
Analyses of chemical residues in animal tissue matrices require multistep sample preparation. Tosimplify this process, a methodology was developed that combines sorbent extraction and solid-matrix time-resolved luminescence (TRL); it was applied to tetracycline screening in milk. Reportedhere is an effort to extend its application to tissue matrices, illustrated by oxytetracycline (OTC)screening in catfish muscle. Extraction and enrichment are accomplished by immersing small C18sorbent strips into tissue homogenates for 20 min, followed by a 3 min rinse in water and a 2 min dipin a reagent solution. After desiccation, TRL is measured directly on the sorbent surface. Tissueparticulates no longer interfere via attenuation or scattering, rendering centrifugation and filtrationunnecessary. The integrated TRL intensity shows a linear dependence on OTC concentration in the0-8 
g/g range (R 2 = 0.9992) with a 0.026 g/g limit of detection. To screen OTC at 2 g/g, theU.S. regulatory tolerance level, a threshold is established at 
2 - 3
2, where 2 and 2 are the meanand standard deviation, respectively, of the TRL signals from 15 samples fortified at 2 g/g. Among45 blind samples randomly fortified at 0-4 g/g, 41 were screened correctly and 4 negative sampleswere presumed positive. This method has the potential to improve throughput and save assay costsby eliminating acids, organic solvents, centrifugation, and filtration.Keywords: Time-resolved luminescence; screening; antibiotic; oxytetracycline; sorbent extraction;fish; tissue
g/g range (R 2 = 0.9992) with a 0.026 g/g limit of detection. To screen OTC at 2 g/g, theU.S. regulatory tolerance level, a threshold is established at 2 - 32, where 2 and 2 are the meanand standard deviation, respectively, of the TRL signals from 15 samples fortified at 2 g/g. Among45 blind samples randomly fortified at 0-4 g/g, 41 were screened correctly and 4 negative sampleswere presumed positive. This method has the potential to improve throughput and save assay costsby eliminating acids, organic solvents, centrifugation, and filtration.Keywords: Time-resolved luminescence; screening; antibiotic; oxytetracycline; sorbent extraction;fish; tissue