基于低共熔溶剂的悬浮固化分散液液微萃取测定水体中4种邻苯二甲酸酯

Dispersive liquid-liquid microextraction based on the solidification of floating organic droplets in deep eutectic solvents for the determination of four phthalate esters in water

设计并制备了6种可低温固化的疏水性低共熔溶剂(DESs)。将其作为萃取剂,建立了一种悬浮固化分散液液微萃取(SFO-DLLME)方法,结合气相色谱法(GC),对水体环境中4种邻苯二甲酸酯(PAEs)进行富集测定。最佳萃取条件为:50μL麝香草酚和癸酸以摩尔比2∶1形成的低共熔溶剂(DES-4)作为萃取剂,超声5 min,样品溶液中NaCl浓度为2%(w/V),pH 5。在优化条件下,4种PAEs在5~800μg/L范围内呈良好的线性关系,相关系数R^(2)为0.9921~0.9985,检出限为1~2.5μg/L。将建立的方法应用于市售塑料瓶装矿泉水、自来水和河水样品中4种PAEs的测定,3个浓度水平下加标回收率为75.5%~119.0%,相对标准偏差为0.43%~8.9%。该方法可用于水体环境中4种PAEs的富集测定。

Six hydrophobic deep eutectic solvents(DESs)that can be solidified at low temperature were designed and prepared with thymol and menthol as hydrogen bond donors and decanoic acid,hexanoic acid and decanol as hydrogen bond acceptors.These DESs were used as extractants to develop a dispersive liquid-liquid microextraction method based on the solidification of floating organic droplets(SFO-DLLME)for the enrichment and determination of four phthalate esters in combination with gas chromatography(GC).The optimal extraction conditions were as follows:DES-4(nthymol/ndecanoic acid=2∶1)with a volume of 50μL as the extractant,ultrasonication for 5 min,2%(w/V)NaCl in the sample solution and pH 5.Under the optimum extraction conditions,the method showed good linear relationships in the range of 5-800μg/L with the correlation coefficients(R^(2))of 0.9921-0.9985 and the limits of detection of 1-2.5μg/L.The established method was used for the enrichment and determination of four phthalatic esters(PAEs)in commercially available plastic bottle-packaged mineral water,tap water,and river water.The spiked recoveries of the four PAEs at the three spiked concentrations were 75.5%-119.0%,with the relative standard deviations(RSDs)of 0.43%-8.9%.This method can be used for the enrichment and determination of the four PAEs in the aqueous environment.