磁性羟基化多壁碳纳米管萃取结合气相色谱-质谱法检测水中28种农药

Determination of 28 Pesticides in Water Using Magnetic Hydroxylated Multi-walled Carbon Nanotubes and Gas Chromatography-Mass Spectrometry

采用共沉淀法合成了Fe_(3)O_(4)纳米粒子修饰的羟基化多壁碳纳米管(Fe_(3)O_(4)-MWCNTs-OH),利用扫描电子显微镜、振动样品磁力计、X射线衍射多种方式表征,并确定Fe_(3)O_(4)粒子附着于MWCNTs-OH,形成直径约100~300 nm的纳米颗粒,这使得材料的磁力强度最大达到了5.48 emu/g,证明了其具有良好的顺磁性。以此为基础,结合气相色谱-质谱联用,选择离子扫描技术,建立了同时测定水中28种农药(如甲拌磷、甲草胺和甲氰菊酯等)的方法。实验分别考察了萃取剂用量、萃取时间、解析溶剂等因素对萃取效果的影响,并对萃取条件进行优化。结果表明,在震荡混匀时间为10 min、材料使用量为10 mg和乙酸乙酯作为最佳解吸溶剂的条件下,该方法能够呈现良好的线性关系,相关系数R^(2)≥0.991,方法检出限为13.5~300 ng/L,定量限为44.8~1000 ng/L,证明了本方法具有灵敏度高、线性范围宽的优点,适用于水中多种农药的同时测定。

Fe_(3)O_(4)nanoparticle-modified hydroxylated multi-walled carbon nanotubes(Fe_(3)O_(4)-MWCNTs-OH)were synthesized using a co-precipitation method.The synthesized material was characterized using scanning electron microscopy,vibrating sample magnetometer,and X-ray diffraction.It was observed that the Fe_(3)O_(4)particles were attached to MWCNTs-OH,forming nanoparticles with a diameter ranging from 100 to 300 nm.This nanoparticle modification resulted in a maximum magnetic strength of 5.48 emu/g,indicating excellent paramagnetic properties.Building upon this,a method for the simultaneous determination of 28 pesticides in water(such as phorate,alachlor,and fenpropathrin)was developed using gas chromatography-mass spectrometry-selected ion scanning technology.We conducted separate investigations on the effects of various factors such as the amount of sorbents,extraction time,and solvent on the extraction process.We optimized the extraction conditions and found that when the shaking and mixing time is set to 10 min,the material usage is 10 mg,and ethyl acetate is used as the optimal desorption solvent,the method shows a good linear relationship(R^(2)≥0.991).The method detection limit ranges from 13.5 to 300 ng/L,and the limit of quantification ranges from 44.8 to 1000 ng/L.These results demonstrate that this method offers high sensitivity and a wide linear range,making it suitable for the simultaneous determination of multiple pesticides in water.