低共熔溶剂分散液液微萃取-悬浮固化-高效液相色谱法测定水产品中3种内分泌干扰物的含量

Determination of 3 Endocrine Disrupting Chemicals in Fishery Products by HPLC with Deep Eutectic Solvents Dispersive Liquid Liquid Microextraction-Solidification of Floating Droplets

将癸酸和香叶醇在10 mL玻璃管中以2∶1的物质的量之比混合,然后将混合物在80℃水浴锅中加热,直至形成稳定的低共熔溶剂(DES)。该溶剂易合成、低成本、低毒性且具有高生物降解性,是一种新型的疏水性DES,可用于水产品中内分泌干扰物的微萃取。取已粉碎的水产品样品1 g和乙腈2 mL置于5 mL离心管中,以转速2 000 r·min^(-1)涡旋振荡3 min。取上清液400μL,经0.45μm滤膜过滤,滤液与100μL DES混合,并迅速注入装有5 mL 80 g·L^(-1)氯化钠溶液的10 mL离心管中,以完成DES的分散。将上述离心管以转速3 500 r·min^(-1)离心5 min,然后置于冰浴中进行固化。将固化后所得样品溶解于150μL甲醇中,以Eclipse Plus C;色谱柱为分离柱,以体积比90∶10的甲醇-水的混合液为流动相,在激发波长228 nm,发射波长305 nm处测定双酚A、4-叔辛基苯酚和壬基酚等3种内分泌干扰物的含量。结果表明,DES在冰浴中固化,可促进其从水溶液中分离,简单且快速,利于萃取剂的收集。3种内分泌干扰物的质量分数均在0.25~10μg·g^(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)均为0.075μg·g^(-1)。用此法对空白加标样品进行测定,测定值的日内和日间相对标准偏差(n=5)均小于4.0%。以空白样品为基体进行加标回收试验,所得回收率为78.7%~91.6%。

Decanoic acid and geraniol were mixed in a 10 mL-glass tube at a molar ratio of 2∶1, and then the mixture was heated in a water bath at 80 ℃ until a stable deep eutectic solvent(DES) was prepared. The solvent had the advantages of easy synthesis, low cost, low toxicity and high biodegradability. It was a new hydrophobic DES, which could be used for the microextraction of endocrine disrupting chemicals in fishery products. 1 g of crushed sample and 2 mL of acetonitrile were placed into a 5 mL-centrifuge tube and oscillated in a vortex at 2 000 r·min^(-1)for 3 min. 400 μL of the supernatant was taken, and passed through 0.45 μm filter membrane. The obtained filtrate and 100 μL of DES were mixed and quickly injected into a 10 mL-centrifuge tube containing 5 mL of 80 g·L^(-1)sodium chloride solution to complete the dispersion of DES. The above centrifuge tube was centrifuged at 3 500 r·min^(-1)for 5 min, and then placed in an ice bath for solidification. The solidified sample was dissolved in 150 μL of methanol, and separated with Eclipse Plus C;as the separation column and a mixed solution of methanol and water in volume ratio of 90∶10 as the mobile phase. Determination of 3 endocrine disrupting chemicals, including bisphenol A, 4-tertoctyl phenol and nonylphenol, was carried out at the excitation wavelength of 228 nm and the emission wavelength of 305 nm. As shown by the results, solidification of DES in ice bath could promote its separation from aqueous solution, which was simple and fast, and was conducive to the collection of extractant. Linear relationships between values of peak areas and mass fraction of 3 endocrine disrupting chemicals were found in the same range of 0.25-10 μg·g^(-1), with the same detection limits(3 S/N) of 0.075 μg·g^(-1). This method was applied for determination of the blank spiked sample, with RSDs(n=5) of the determined values of intra-day and inter-day less than 4.0%. Test of recovery was made with the blank sample as the matrix by standard addition method, giving results in the range of 78.7%-91.6%.