双频超声辅助酶解提取-石墨炉原子吸收光谱法测定玉米中镉和铅  

Determination of Cd(Ⅱ)and Pb(Ⅱ)in corn using dual-frequency ultrasound-assisted enzymatic digestion coupled with graphite furnace atomic absorption spectrometry

作　　者：孟登辉 曹慧[1] 徐斐[1] 叶泰[1] 袁敏[1] 黎燕 于劲松[1] 阴凤琴 吴秀秀 MENG Denghui;CAO Hui;XU Fei;YE Tai;YUAN Min;LI Yan;YU Jinsong;YIN Fengqin;WU Xiuxiu(Shanghai Engineering Research Center for Food Rapid Detection,University of Shanghai for Science and Technology,Shanghai 200093)

机构地区：[1]上海食品快速检测工程技术研究中心,上海理工大学医疗器械与食品学院,上海200093

出　　处：《分析试验室》2022年第1期75-80,共6页Chinese Journal of Analysis Laboratory

基　　金：国家重点研发计划项目(2017YFC1600603)资助。

摘　　要：建立了双频超声辅助酶解提取(DUED)对玉米中Cd(Ⅱ)和Pb(Ⅱ)进行提取的方法,并结合石墨炉原子吸收光谱法(GFAAS)对其检测。结果表明,双频超声辅助酶解提取方法的最佳酶解条件为:0.1 mLα-淀粉酶+0.1 g中性蛋白酶+0.2 g木瓜蛋白酶、2.5 mL提取剂(pH 5.0)和60℃的提取温度。最佳超声参数为:40 kHz超声水浴+20 kHz超声探头、400 W超声水浴功率和630 W超声探头功率。在最优条件下,6 min时对玉米样品中Cd(Ⅱ)和Pb(Ⅱ)的提取率即达到98.9%和108.2%。该方法对3种玉米标准物质(GBW 100380,GBW(E)10049和GBW(E)100498)中Cd(Ⅱ)和Pb(Ⅱ)的回收率为94.4%~109.1%,检出限分别为0.24和6.9μg/kg,相对标准偏差均小于10%。该方法已应用于玉米样品中Cd(Ⅱ)和Pb(Ⅱ)的测定。A novel dual-frequency ultrasonic-assisted enzymatic digestion method(DUED)was developed for the efficient extraction of Cd(Ⅱ)and Pb(Ⅱ)from corn samples prior to graphite furnace atomic absorption spectrometry(GFAAS)determination.The combination of 40 kHz ultrasonic water bath(400 W)with 20 kHz ultrasonic probe(630 W)greatly improved the efficiency of sample processing and reduced the actual analysis time.Under the optimized conditions,the combination of 0.1 mLα-amylase,0.1 g neutrase,and 0.2 g papain can extract 98.9%of Cd(Ⅱ)and 108.2%of Pb(Ⅱ)in 0.5 g corn samples in 2.5 mL HAc-NaAc buffer(pH 5.0)within 6 min at 60℃.Three certified reference materials(GBW 100380,GBW(E)10049 and GBW(E)100498)were used to evaluate the accuracy and practicability of the method.The recoveries of Cd(Ⅱ)and Pb(Ⅱ)ranged from 94.4%to 109.1%,and the limits of detection were 0.24 and 6.9μg/kg,respectively.The relative standard deviations of the two elements were all lower than 10%.The proposed method has been applied to determine Cd(Ⅱ)and Pb(Ⅱ)in corn samples.

关 键 词：双频超声辅助酶解 石墨炉原子吸收光谱 玉米 镉 铅 

分 类 号：TS210.7[轻工技术与工程—粮食、油脂及植物蛋白工程] O652.6[轻工技术与工程—食品科学与工程]