麦冬中金属及有害元素与农药残留测定研究

Determination of Metal Elements,Harmful Elements and Pesticide Residues in Ophiopogon Japonicus

目的建立麦冬中金属及有害元素与农药残留的测定方法。方法采用电感耦合等离子体-质谱法测定麦冬药材中16种金属及有害元素的含量,射频功率为1300 W,氩气流速为15.0 L/min,辅助气流速为0.10 L/min,雾化气流速为0.9 L/min,采样深度为7.0 mm,采样锥孔径为1.0 mm,雾室温度为2℃。采用气相色谱串联质谱法测定麦冬药材中30种农药残留量,色谱柱为HP-5MS毛细管柱(30 m×0.25 mm,0.25μm),进样口温度为240℃,进样方式为不分流,载气为高纯度氦气,恒压模式,流速为1.3 m L/min,进样量为1μL,程序升温;离子源为电子轰击源;监测模式为多反应监测模式,离子源温度为230℃,质谱传输接口温度为280℃,碰撞气体为氩气;溶剂延迟时间为1.5 min。结果硼(B)、铝(Al)、铁(Fe)、铜(Cu)质量浓度均在0~200μg/L,钪(Sc)、镍(Ni)、锌(Zn)、砷(As)、硒(Se)、锶(Sr)、镉(Cd)、锡(Sn)、碲(Te)、钡(Ba)、铅(Pb)质量浓度均在0~40μg/L,汞(Hg)质量浓度在0~8μg/L范围内与仪器信号强度线性关系良好(r>0.995);重复性试验的RSD均小于4.10%(n=9);平均加样回收率均为87.01%~102.41%,RSD均为1.21%~4.41%(n=9)。α-六六六、β-六六六、γ-六六六、特丁硫磷、δ-六六六、三氯杀螨醇、p,p'-DDE、p,p'-DDD、o,p'-DDT、内吸磷、灭线磷、氟甲腈、甲基异柳磷、氟虫腈亚砜、氟虫腈砜质量浓度均在5~200 ng/m L,甲基对硫磷、艾氏剂、对硫磷、氟虫腈、除草醚、甲拌磷、水胺硫磷、特丁硫磷亚砜、特丁硫磷砜质量浓度均在10~200 ng/m L,杀虫脒质量浓度在15~200 ng/m L,α-硫丹、β-硫丹、久效磷质量浓度均在20~200 ng/m L,蝇毒磷质量浓度在30~200 ng/m L,狄氏剂质量浓度在35~200 ng/m L范围内与峰面积线性关系良好(r>0.994);检测限均为0.005~0.025 mg/kg;精密度试验结果的RSD均小于6.22%(n=9);平均回收率均为70.50%~89.33%,RSD均为1.41%~9.45%(n=9)。12批药材样品中铝含量为41.98~423.74 mg/kg,铁含量为67.76~321.73 mg/kg;均未检出农药残留。结论所建立的方法简便、快速、灵敏、可靠,可用于麦冬药材中多种金属及有害元素和农药残留的测定。麦冬药材中金属及有害元素污染物含量较少,但有一定含量的铝,应引起重视。麦冬在种植过程中无序使用农药现象较少,安全风险较低。

Objective To establish a method for the determination of metal elements,harmful elements and pesticide residues in Ophiopogon japonicus.Methods The contents of 16 metal elements and harmful elements in Ophiopogon japonicus were determined by inductively coupled plasma-mass spectrometry(ICP-MS),the radio frequency(RF)power was 1300 W,the flow rate of argon was 15.0 L/min,the flow rate of auxiliary gas was 0.10 L/min,the flow rate of atomization gas was 0.9 L/min,and the sampling depth was 7.0 mm,the diameter of sampling cone was 1.0 mm,and the temperature of fog chamber was 2℃.A total of 30 pesticide residues in Ophiopogon japonicus were determined by the gas chromatography-tandem mass spectrometry(GC-MS/MS)method.The chromatographic column was HP-5 MS capillary column(30 m×0.25 mm,0.25μm),the temperature of the injection port was 240℃,the splitless injection mode was adopted,the carrier gas was high-purity helium,the constant pressure mode was adopted,the flow rate was 1.3 m L/min,the injection volume was 1μL,programmed-temperature was adopted,the ion source was electron bombardment source,the monitoring mode was multiple reaction monitoring mode,the temperature of ion source was 230℃,the temperature of mass spectrometry transmission interface was 280℃,the collision gas was argon,and the solvent delay time was 1.5 min.Results The mass concentration of boron(B),aluminum(Al),iron(Fe),copper(Cu)showed a good linear relationship with the signal intensity of the instrument in the range of 0-200μg/L,the mass concentration of scandium(Sc),nickel(Ni),zinc(Zn),arsenic(As),selenium(Se),strontium(Sr),cadmium(Cd),tin(Sn),tellurium(Te),barium(Ba)and lead(Pb)showed a good linear relationship with the signal intensity of the instrument in the range of 0-40μg/L,the mass concentration of mercury(Hg)showed a good linear relationship with the signal intensity of the instrument in the range of 0-8μg/L(r>0.995).The RSD of the repeatability test was less than 4.10%(n=9).The average recoveries of 16 metal elements and harmful elements were in the range of 87.01%-102.41%with RSDs of 1.21%-4.11%(n=9).The mass concentrations ofα-hexachlorocyolohexane,β-hexachlorocyolohexane,γ-hexachlorocyolohexane,terbuthion,δ-hexachlorocyolohexane,dicofol,p,p’-DDE,p,p’-DDD,o,p’-DDT,demeton,ethoprophos,fipronil-desulfinyl,isofenphos-methyl,fipronil-sulfide,fipronil-sulfone showed a good linear relationship with the peak area in the range of 5-200 ng/m L,the mass concentrations of parathion-methyl,aldrin,parathion,fipronil,nitrofen,phorate,isocarbophos,terbufos-oxon-sulfoxide,and terbufos-sulfone showed a good linear relationship with the peak area in the range of 10-200 ng/m L,the mass concentration of chlordimeform showed a good linear relationship with the peak area in the range of 15-200 ng/m L,the mass concentration ofα-endosulfanβ-endosulfan and monocrotophos showed a good linear relationship with the peak area in the range of 20-200 ng/m L,the mass concentration of coumaphos showed a good linear relationship with the peak area in the range of 30-200 ng/m L,the mass concentration of dieldrin showed a good linear relationship with the peak area in the range of 35-200 ng/m L(r>0.994).The limits of detection(LOD)of 30 pesticide residues were in the range of 0.005-0.025 mg/kg.The RSDs of the precision test were less than 6.22%(n=9).The average recoveries of 30 pesticide residues were in the range of 70.50%-89.33%with RSDs of 1.41%-9.45%(n=9).The contents of aluminum and iron in 12 batches of samples were 41.98-423.74 mg/kg and 67.76-321.73 mg/kg,respectively.No pesticide residues were detected in the samples.Conclusion The method is simple,rapid,sensitive and reliable,which can be used for the determination of metal elements,harmful elements and pesticide residues in Ophiopogon japonicus.The contents of metal elements and harmful elements in Ophiopogon japonicus are less,but a certain amount of Al should be paid attention to.The disorderly use of pesticides in the planting process of Ophiopogon japonicus is less,and the safety risk is low.