MWCNTs净化高效液相色谱测定豆芽中的尿素  

Determination of Urea in Bean Sprouts by HPLC/UV with MWCNTs SPE

作　　者：冯建华 贺丽华 赵海超[1] 赵海香[1,2] FENG Jian-hua;HE Li-hua;ZHAO Hai-chao;ZHAO Hai-xiang(Department of Chemistry,School of Sciences,Hebei North University,Zhangjiakou,Hebei 075000,China;Institute of Applied Chemistry,Hebei North University,Zhangjiakou,Hebei 075000,China)

机构地区：[1]河北北方学院理学院化学系,河北张家口075000 [2]河北北方学院应用化学研究所,河北张家口075000

出　　处：《河北北方学院学报（自然科学版）》2020年第9期8-14,共7页Journal of Hebei North University:Natural Science Edition

基　　金：河北省科技计划项目(14227115D);河北北方学院博士基金项目(BSJJ201811)。

摘　　要：目的建立黄豆芽和绿豆芽中尿素残留测定的高效液相色谱法。方法尿素残留采用纯水超声提取,10000 rpm离心,上清液经多壁碳纳米管固相萃取柱净化,收集流出液,经Symmetry C18色谱柱分离,乙腈、水为流动相,采用梯度洗脱,0.4 mL/min流速,紫外检测器的波长为200 nm进行测定。结果该方法在0.05~50 mg·L-1范围内线性良好,线性相关系数R 2=0.999,豆芽样品中尿素的检出限为0.5 mg·kg-1,黄豆芽中尿素的添加回收率为78.4%~86.4%,绿豆芽为75.3%~89.6%。用于实际豆芽样品中尿素的测定,发现市场出售豆芽中尿素的检出率为50%,含量为1.53~2.43 mg·kg-1;超市购买的豆芽检出率为20%,含量为1.23~1.51 mg·kg-1;有机或绿色豆芽中没有检出尿素。结论多壁碳纳米管净化方法能较好消除基质干扰,高效液相色谱测定方法克服了光度法测定中假阳性的缺点,适用于豆芽菜中尿素的检测,实际样品检测结果表明豆芽菜中存在使用尿素的现象。Objective A HPLC/UV method was developed to determine urea residue in soybean sprouts and mungbean sprouts.Methods The urea residue was extracted by ultrasonic assistant extraction with water,and centrifuged at 10,000 rpm.The extract was cleaned up by MWCNTs SPE cartridge,collected effluent,and determined by HPLC with an UV detector at 200 nm.Results The linear range of method was from 0.05 mg·L-1 to 50 mg·L-1 with the correlation coefficient of over 0.999.The limit of quantification(S/N=10)was 0.5 mg·kg^-1 in bean Sprouts.The spiked recoveries were in the range of 78.4%to 86.4%in soybean sprouts,and from 75.3%to 89.6%in mungbean sprout.The method was used for determination of urea in actual bean sprout samples.The urea detection rate was 50%for bean sprouts bought from the market,and the content of urea was from 1.53 mg·kg^-1 to 2.43 mg·kg^-1.The urea detection rate was 20%for bean sprouts bought from the supermarket,and the content of urea as from 1.23 mg·kg^-1 to 1.51 mg·kg^-1.The urea was not found in the organic or green bean sprouts.Conclusion MWCNTs purification method better eliminates matrix interference.HPLC/UV overcome the shortcomings of false-positivity in photometric determination.It is suitable for the detection of urea in bean sprouts.The detection results of actual samples show that urea is used in bean sprouts.

关 键 词：多壁碳纳米管 高效液相色谱 豆芽 尿素 

分 类 号：O657.63[理学—分析化学]