摘要
建立了简便、灵敏地检测烟草中菌核净残留的时间分辨荧光免疫分析方法(TRFIA),及配套的无净化的快速前处理技术。采用镧系元素螯合物Eu-N1标记亲和纯化后的羊抗兔IgG示踪抗体。采用间接竞争TRFIA法建立了菌核净标准抑制曲线,方法的检出限I10为2.0μg/L;抑制终浓度I50为32.00μg/L;检测线性范围为4～128μg/L。考察了丙酮提取后33%,10%和1%的烟草基质对菌核净-TRFIA分析方法的影响,表明在1%烟叶基质条件下,建立的菌核净的抑制曲线的线性范围与标准抑制曲线趋于平行,确定烟草样品的前处理稀释倍数为100倍,计算得到基质影响因子(Im)为17.1。对烟叶样品中添加1,7和24mg/L的菌核净标样,连续3d的添加回收实验表明,方法的回收率为73%～128%,相对标准标准偏差(RSD)在4.3%～13.2%之间;烟草中菌核净的实际最低检出限为1mg/L。本方法可望用于烟草中菌核净残留的快速筛选检测。
A sensitive time-resolved fluorescence immunoassay （TRFIA） with a cleanup-free pretreat- ment for dimethachlon in tobacco was developed. The competitive indirect TRFIA for dimethachlon was established by using goat anti-rabbit IgG conjugated with a Eu-N1 clelate as a tracer. The detection limit （I10） and Is0 for this assay was 1.98 μg/L and 32.00 μg/L, respectively. And the linear range for detection is between 3.97--128.76 μg/L. Meanwhile, the effect of tobacco matrix to TRFIA was also studied. It was demonstrated that the linear range of inhibition curve with 1~ tobacco matrix was parallel to the standard curve; so the extract of tobacco would be diluted 100 times before assay, the index of matrix interference （In） was calculated as 17. 1. Three levels of dimethachon （1, 7 and 24 mg/L） were spiked into tobacco, the overall recoveries and the relative standard deviations （RSDs） were in the range of 73%--128% and 4.3--13.2, and the practical detection limit for the method was 1 mg/L. This assay is a suitable tool for screening dimethachlon residue in tobacco samples
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2012年第7期1114-1117,共4页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金项目(No.30871658)
农业部948项目(Nos.2011-Z46
2011-G5-7)资助
关键词
菌核净
时间分辨荧光免疫分析
烟草
样品前处理
Dimethachlon
Time-resolved fluorescence immunoassay
Tobacco
Sample pretreatment
