摘要
建立了测定牛奶中头孢拉定的荧光增敏分光光度法。该方法基于头孢拉定在碱性条件下降解之后降解产物荧光强度增强，并且降解产物的荧光强度可以被表面活性剂吐温-20增敏，增敏产物的激发和发射波长分别位于340nm和450nm处。考察了缓冲溶液、NaOH溶液的用量、反应温度和时间、表面活性剂等因素对体系荧光强度的影响。结果表明：头孢拉定质量浓度在0．1—1．5μg／mL范围内遵循比尔定律，线性回归方程为：F=516．57p＋34．14，相关系数R。=0．999，并探讨了其反应机理。方法应用于牛奶中头孢拉定的检测，样品的加标回收率在90．6％-104．5％之间，检出限为0．045μg／mL，相对标准偏差为1．3％。
Cephradine is a β-actam antibiotic widely used for treating certain bacterial infections in beef and dairy cattle. Therefore, it was necessary to develop a highly sensitive and selective method to analyze cephradine. In this article, a new spectrofluorimetric method has been developed for the determination of trace amounts of cephradine in milk samples. The method was based on that cephradine degradation under an alkaline condition produced a flu- orescent product and its fluorimetric intensity could be markedly enhanced by polyoxyethy-lene （20） sorbitan mono- laurate. The fluorescence of the sensitized product was at an emission wavelength of 450 nm after being excited at 340 nm. Several factors including selection of buffer solution, reaction temperature and time, amount of NaOH and effect of the surfactant were studied and optimized. The results showed that the concentration of cephradine obeyed the Beer＇s law in the range of 0.1 ~ 1.5 μg/mL and the regression equation was I = 516.57p ＋ 34.14 with the cor- relation coefficient R2 of 0.999, and the apparent molar absorptivity was 1.80 × 10^5 L · moL· cm -1 Further- more, the reaction mechanism was explored. The high sensitivity of the proposed method was applied to the deter- ruination of cephradine in milk samples and satisfactory results were obtained. The recoveries of the studied com- pound were in the range of 90.6% ~ 104.5% with the detection limit of 0.045 μg/mL, and the maximum relative standard deviation was 1.3%. The main advantages of our method were simple, rapid and accurate. The method could be used for a rapid and cost-effective alternative for the quality control of cephradine in milk.
出处
《分析试验室》
CAS
CSCD
北大核心
2014年第1期92-95,共4页
Chinese Journal of Analysis Laboratory
基金
云南省自然科学基金项目(2010ZC207)资助
关键词
头孢拉定
碱性降解
荧光增敏
牛奶
Cephradine
Alkalinedegradation
Fluorescence sensitization
Milk
