Vicente-Martínez Yesica, Caravaca Manuel, Soto-Meca Antonio
Spanish Air Force Academy, University Centre of Defence, Coronel López Peña st., n/n, 30720 Murcia, Spain.
Pharmaceuticals (Basel). 2020 Oct 12;13(10):301. doi: 10.3390/ph13100301.
Bisphenol A (BPA) is a chemical compound used in the manufacturing of plastics and resins whose presence in the body in low concentrations can cause serious health problems. Due to this, there is a growing interest in the scientific community to develop analytical methods that allow quantifying trace concentrations of BPA in different types of samples. The determination of this compound in toys made of plastics that can be manipulated by children leads to an extra concern, because it is possible for BPA to enter the body by introducing these toys into the mouth. This work presents a novel procedure to the quickly and easily quantification of trace levels of BPA in samples of toys and pacifiers according to the current demanding regulations. The determination of very low levels of BPA was carried out by ionic liquid dispersive liquid-liquid microextraction (IL-DLLME) followed by high-performance liquid chromatography (HPLC). The formation in situ of the ionic liquid (IL) 1-octyl-3-methylimidazolium bis((trifluoromethane)sulfonyl)imide ([CMIm] [NTf]), was achieved by mixing 1-octyl-3-methylimidazolium chloride ([CMIm]Cl) and lithium bis(trifluoromethanesulfonyl)imide ([NTf]Li) aqueous solutions, reaching an instant dispersion whose cloud of microdrops allows the total extraction of BPA in the IL from aqueous solutions. After centrifugation, BPA concentration in the sedimented phase was determined by HPLC. The optimal experimental conditions for the microextraction and determination of BPA in the IL were studied. The total extraction was achieved at pH 4, heating the sample at 30 °C for 5 min, using 100 µL of IL precursor volume, and spinning after the formation of dispersion at 3000 rpm for 10 min. The enrichment factor (EF) and detection limit (LOD) reached with the procedure were 299 and 0.19 µg L, respectively. The relative standard deviation for ten replications at the 0.5 µg L level was 5.2%. Recovery studies showed a mean value for BPA recovery percentage in the samples of 99%. Additionally, a hybrid model was applied to characterize the extraction kinetics. This simple, low cost and fast method simplifies traditional microextraction techniques, representing an outstanding alternative.
双酚A（BPA）是一种用于制造塑料和树脂的化合物，其在体内的低浓度存在会导致严重的健康问题。因此，科学界对开发能够定量不同类型样品中痕量BPA的分析方法的兴趣与日俱增。对儿童可接触的塑料玩具中这种化合物的测定引发了额外的关注，因为将这些玩具放入口中可能会使BPA进入人体。这项工作根据当前严格的法规，提出了一种新颖的方法，可快速、轻松地定量玩具和安抚奶嘴样品中的痕量BPA。通过离子液体分散液液微萃取（IL-DLLME）结合高效液相色谱（HPLC）来测定极低水平的BPA。离子液体（IL）1-辛基-3-甲基咪唑双（（三氟甲烷）磺酰）亚胺（[CMIm][NTf]）通过混合1-辛基-3-甲基咪唑氯盐（[CMIm]Cl）和双（三氟甲烷磺酰）亚胺锂（[NTf]Li）水溶液原位形成，形成即时分散体，其微滴云允许从水溶液中完全萃取IL中的BPA。离心后，通过HPLC测定沉淀相中BPA的浓度。研究了IL中BPA微萃取和测定的最佳实验条件。在pH 4、将样品在30℃加热5分钟、使用100μL的IL前体体积并在分散体形成后以3000 rpm旋转10分钟的条件下实现了完全萃取。该方法达到的富集因子（EF）和检测限（LOD）分别为299和0.19μg/L。在0.5μg/L水平下进行十次重复的相对标准偏差为5.2%。回收率研究表明样品中BPA回收率的平均值为99%。此外，应用了一个混合模型来表征萃取动力学。这种简单、低成本且快速的方法简化了传统的微萃取技术，是一种出色的替代方法。
