镁铝铁层状金属氢氧化物固相萃取有机磷农药的研究

建立镁铝铁层状金属氢氧化物(Mg-Al-Fe-LDH)复合材料固相萃取气相色谱质谱法(GC-MS)测定水中的敌敌畏,乐果,氯吡硫磷,水胺硫磷的分析方法.复合材料用量为2 g,萃取12 min,二氯甲烷作为洗脱剂,洗脱剂用量为2 mL,洗脱时间1 min,4种农药的质量浓度在0.01～10 ng/mL范围内与峰面积线性关...

Study on solid phase extraction of organophosphorus pesticides with magnesium-aluminum-iron layered metal hydroxides

A method for the determination of dichlorvos, dimethoate, chlorpyrifos and isocarbophos in water by solid phase extraction gas chromatography-mass spectrometry(GC-MS) with magnesium-aluminum-iron layered metal hydroxide(Mg-Al-Fe-LDH) composite was established. When the amount of Mg-Al-Fe-LDH was 2 g, the extraction time was 12 minutes, the eluant was 2 mL dichloromethane, and the elution time was 1 min,the mass concentration of four pesticides in the range of 0.01-10 ng/mL had a good linear relationship with the peak area, the correlation coefficients were greater than 0.99, and the relative standard deviation were 1.1%-3.6% and the detection limit of the method were 0.001-0.03 ng/mL. The recovery rate are 95.0%-120%, and the relative standard deviation are 1.2%-6.5%. Iron replaces part of the aluminum into the laminate in Mg-Al-FeLDH. Fe3+ has empty orbits at the 4 s energy level, which can form coordination bonds with phosphorus and sulfur containing lone pairs of electrons in organic phosphorus pesticides, further enhancing Adsorption capacity. The method based on Mg-Al-Fe-LDH solid phase extraction has low detection limit and high accuracy which can meet the determination requirements of trace organophosphorus pesticides in water.