Qianjun Liu,Jiepeng Tang,Di Chen,Yangmei Zhou,Qintie Lin,Xiaoguo Ma,Min Zhang,Huawen Hu
To detect, identify, and quantify the polycyclic aromatic hydrocarbons (PAHs) released into the environment, the PAHs need to be isolated from the soil matrix. In this work, a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method with ionic liquid was combined with liquid chromatography to identify 16 selected PAHs in soil. Ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate ([Hmim]PF 6 ) was applied as an extractant component to enhance the process. The [Hmim]PF 6 content in acetonitrile (ACN) was optimized. The [Hmim]PF 6 modified QuEChERS method has the advantages defined by its name and a similar recovery to other extraction methods reported in the literature. Adding [Hmim]PF 6 may eliminate the co-extract proportion and achieve a more effective extraction. Compared with ACN alone, the matrix effect (ME) of ACN containing 5% [Hmim]PF 6 was reduced by approximately 35%. Additionally, the ME of using ACN containing [Hmim]PF 6 without a clean-up procedure was similar to that of using ACN followed by a clean-up procedure. The recoveries of the QuEChERS method implemented with [Hmim]PF 6 ranged from 75.19% to 100.98%. The limits of detection (LOD) and limits of quantification (LOQ) ranged from 0.86 to 4.51 µg/kg and from 2.87 to 15.13 µg/kg, respectively.
Zhen Jiao,Mengnan Zhang,Lixia Yang,Yuxuan Wang,Jiajie Fu
To evaluate the feasibility of extraction of 1-methylimidazole from its low-concentration aqueous solution by ionic liquids, the liquid–liquid equilibrium of the ternary system of water + 1-methylimidazole + ionic liquid ([Hmim][PF6], [Omim][PF6], or [Omim][BF4]) was determined at 303.15 K and atmospheric pressure. The distribution coefficient and selectivity were calculated in accordance with the experimental results. The effects of the anion and cation of ionic liquids on the separation ability were discussed. The results indicated that the extraction capacity increased with increasing cationic carbon chain length, and the change of anions significantly affected the distribution coefficient and selectivity. As expected, the three ionic liquids were feasible as extractants for separating 1-methylimidazole from water. It also indicated that [Omim][PF6] was a more suitable extractant than [Hmim][PF6] and [Omim][BF4] for the extraction. The highest distribution coefficient and selectivity of [Omim][PF6] could reach 1.71 and 111.92, respectively, indicating [Omim][PF6] as a good choice for extracting 1-methylimidazole from water. In addition, the non-random two-liquid model was employed to successfully correlate the experimental data with a root-mean-square deviation of less than 0.0188. Moreover, a GUI-MATLAB tool was used to verify the consistency of the correlated parameters.
危险品化学品经营许可证（带存储）