中文摘要：

本文将磁芯-硫脲壳聚糖作为固定相填充到自制的微柱中,采用流动注射在线分离富集与火焰原子吸收法联用对大米中痕量镉进行测定。pH=7.0的试液以3.9mL/min速率采样120s,以0.5mol/L HNO3-0.1mol/L硫脲作为洗脱液,用火焰原子吸收光谱法测定洗脱液中Cd2＋,检测的线性范围为0.02~1.20μg/mL（r=0.9922）,检出限（3σ）为2.5ng/mL,相对标准偏差（RSD）为0.79%（c=1.0μg/mL,n=7）,加标回收率在96.0%~104.2%之间。

英文摘要：

Thiourea chitosan modified with magnetic core was prepared and filled into the prepared microcolumn for flow injection on-line separation and preconcentration,was then combined with the flame atomic absorption spectrometry（FAAS）to determine trace cadmium in rice.The solution was introduced into the flow injection system for 120 sat the rate of 3.9mL/min,and the adsorbed Cd2＋was completely eluted with 0.5mol/L HNO3-0.1mol/L thiourea and introduced directly to the atomizer for FAAS for determination.Under the optimum conditions,the obtained linear calibration curve was in the range of0.02-1.20μg/mL with detection limit（3σ）of 2.5ng/mL,the relative standard deviation（RSD）was0.79%（c=1.0μg/mL,n=7）and the recoveries were 96.0%-104.2%.The proposed method was applied for the determination of trace cadmium in rice samples.