基于氧化石墨烯在大黄中有机氯的含量测定

Content Determination of Organochlorine in Rhubarb Based on Graphene Oxide

目的:采用经典Hummers法自制氧化石墨烯材料,建立大黄中2,4-滴丙酸和2,4,5-三氯苯氧乙酸残留的高效液相色谱(high performance liquid chromatography,HPLC)测定方法。方法:含量测定采用色谱柱Inertsil ODS-3 C_(18)柱(4.60×250mm,5μm);流动相:甲醇-0.1%磷酸梯度洗脱,检测波长230 nm,流速1.0 mL/min,柱温30℃,进样量10μL,利用L_(9)(3^(4))正交试验法,从洗脱时间、氧化石墨烯用量和洗剂浓度三个因素开展考察,对氧化石墨烯萃取药材中有机氯的方法进行优化筛选。结果:2,4-滴丙酸进样量在0.04~0.40μg(R2=0.9998)范围和2,4,5-三氯苯氧乙酸进样量在0.02~0.20μg(R^(2)=0.9993)范围内均呈良好的线性关系。大黄中2,4-滴丙酸和2,4,5-三氯苯氧乙酸的加样平均回收率分别为99.78%(RSD=2.27%)、99.65%(RSD=2.78%);有机氯萃取的最佳工艺:25 g中药大黄的条件下,氧化石墨烯加入量为30 mg,洗脱时间为40 min,丙酮浓度为40%。采用HPLC法检测大黄药材中2,4-滴丙酸和2,4,5-三氯苯氧乙酸的平均含量分别为41.32μg/g和25.87μg/g,确定氧化石墨烯萃取技术在中药检测中的最优方法,为石墨烯复合材料固相萃取技术在中药农药富集分离的应用提供科学依据。

Objective:To establish a method of determining the residual dichlorprop and 2,4,5-trichlo rophenoxyacetic acid in rhubarb after preparing graphene oxide material by Hummers method.Methods:Chromatographic column Inertsil ODS-3 C_(18)column(4.60×250 mm,5μm)was adopted;mobile phase:methanol 0.1%phosphoric acid,gradient elution,detection wavelength 230 nm,flow rate 1.0 mL/min,column temperature 30℃,sample size 10μL,L_(9)(3^(4))orthogonal design was carried out to investigate elution time,the dose of graphene oxide and the concentrations of the lotions,so as to optimize the screening of the extraction methods of organochlorine by using graphene oxide.Results:Dichlorprop and 2,4,5-trichlorophenoxyacetic acid presented good linear relationship in the range between 0.04 and 0.40μg(R^(2)=0.9998),0.02 and 0.20μg(R2=0.9993).Average recovery rates of dichlorprop and 2,4,5-trichlorophenoxyacetic acid contained in rhubarb were 99.78%(RSD=2.27%)and 99.65%(RSD=2.78%)respectively;the optimal extraction process of organochlorine:under the conditions of 25 g rhubarb,the addition of graphene oxide was 30 mg,elution time was 40 min,the percentage of acetone was 40%.Average contents of dichlorprop and 2,4,5-trichlorophenoxyacetic acid contained in rhubarb were 41.32μg/g and 25.87μg/g respectively detected by HPLC.Conclusion:The study has confirmed the best graphene oxide extraction technology in the herbal detection,and it could provide scientific reference for the application of solid phase extraction technology of graphene composite in enrichment and separation of traditional Chinese medicine pesticide.