固相萃取-HPLC法同时测定大米中甲萘威和阿特拉津

建立固相萃取-高效液相色谱二极管阵列检测器(DAD)法同时测定大米中甲萘威和阿特拉津的方法。样品经乙腈提取、净化、旋转蒸发和氮吹浓缩后,用甲醇定容至2 mL,通过XDB-C₁₈(250 mm×4.6 mm,5μm)色谱柱分离,流动相采用甲醇-水(60︰40,V/V),流速0.4 mL/min,柱温40℃,进样量5μL,在220 nm波长下测定。结果表明,在0~2.0μg/mL范围内,甲萘威和阿特拉津呈现良好线性关系,相关系数(R2)均为1.000,检出限分别为1.0μg/kg和3.0μg/kg。对0.2,0.4和0.8 mg/kg这3种不同浓度下甲萘威和阿特拉津准确度和精密度试验,回收率分别为88.3%~102.2%和87.5%~104.3%,相对标准偏差(RSD,n=6)分别为1.2%~3.3%和2.3%~4.7%。试验方法稳定性好、操作简单、灵敏度高,可满足于大米中甲萘威和阿特拉津测定。

Determination of Carbaryl and Atrazine in Rice by High Efficiency Liquid Chromatography with Solid Phase Extraction

A method for the simultaneous determination of carbaryl and atrazine in rice based on high efficiency liquid chromatography/diode array detector(HPLC/DAD)with solid phase extraction was developed.The samples were extracted with acetonitrile,and then the extract liquor was purified,enriched by rotary evaporator and nitrogen blowing instrument and constant volume to 2 mL with methanol,separated on a XDB-C₁₈ column(250 mm×4.6 mm,5μm)with methanol-water solution(60︰40,V/V),the flow rate 0.4 mL/min,the column temperature 40℃,injection volume 5μL and the wavelength of detector 220 nm.The results showed that within the range of 0-2.0μg/mL,it had good linear relationship between the peak area of carbaryl and atrazine and its mass concentration,and the linear correlation coefficient for carbaryl and atrazine was 1.000.The minimum detection limits of quantitation of carbaryl and atrazine were 1.0μg/kg and 3.0μg/kg respectively.The average recoveries were in the ranges of 88.3%-102.2%and 87.5%-104.3%,with relative standard deviations(RSD)1.2%-3.3%and 2.3%-4.7%(n=6)at 0.2,0.4 and 0.8 mg/kg those 3 spiked levels.Those results indicated that the method was accurate,reliable,and sensitive,and could allow for accurate quantification of carbaryl and atrazine in rice.