溶解性有机质浓度及来源对土霉素测定的影响

作为天然水体中常见的物质,溶解性有机质(dissolved organic matter,DOM)对土霉素(oxytetracychine,OTC)测定有明显的影响。通过固相萃取和LC-MS-MS方法研究DOM浓度及来源对OTC测定的基本影响特征。结果表明:不同浓度DOM对OTC的测定影响呈现不稳定的规律;相同浓度但不同来源的DOM存在时,OTC回收率关系为:进口商品DOM<河底土壤DOM<国产商品DOM<沙土DOM≤无DOM。同时,直接用仪器测定单纯的DOM溶液基本不产生OTC的相关信号,这是由于DOM与OTC存在着某种作用关系而导致测定结果发生变化。研究结果可为抗生素类污染物的分析检测和数据校正提供重要参考。

EFFECT OF DOM WITH DIFFERENT CONCENTRATIONS FROM DIFFERENT ORIGINS ON ANALYSIS AND MEASUREMENT OF OTC

Dissolved organic matter ( DOM) in natural water has a significant impact on determination of OTC． Through solid phase extraction and LC-MS-MS， the study focused on the impact characteristics of DOM with different concentrations from different origins in the determination of OTC． The results indicated that DOM with different concentrations had different effect on the determination of OTC，and the recoveries of OTC with nature soil DOM were higher than the commercial DOM presence． When the same concentration of DOM presence，the recoveries of OTC in sandy soil DOM were nearly equivalent to the absence of DOM，and the OTC recoveries decreased by degrees with the presence of domestic commercial DOM，river sedimentary soil DOM，import commercial DOM． At the same time，the signal of OTC didn’t generate by the determination of LC-MS-MS when the same concentrations DOM in the presence of solution，and the results indicated that the relationship between DOM and OTC brought about the determination change． Besides，the study provided the scientific advice for the analyses and data correction of antibiotics pollutants．