Considering the wide synthesis and application of ionic liquids (ILs), the toxicity of ILs has recently gained growing attention. However, few studies focused on IL determination methods in environmental samples. In the present study, we implemented the determination methods for the 12 ILs with different chemical structures using high-performance liquid chromatography (HPLC) and ultraviolet (UV) spectrophotometry. The optimum conditions for extraction of ILs from soil samples were also obtained by single-factor experiments and response surface methodology (RSM). The instrument detection limits (IDLs) reached 10^–10 g. Compared to the use of UV, HPLC had the standard curve with stronger correlation (R² ≥ 0.999) and lower detection limit. We therefore used HPLC to detect the contents of ILs in water and soil samples. A standard adding method was used for the reliability test of the above methods. The average recovery in water samples was 90.46%–108.83%, and the coefficient of variation (CV) was 0.51%–9.07%. The method detection limits (MDLs) were below 0.1 mg/L. The optimized IL extraction conditions in soil samples were as follows: The ratio of methanol and saturated ammonium chloride was 90:10, the ultrasonic time was 50 min, and the power was 350 W. The average recovery in soil samples was 70.39%–85.30%, and the CV was 0.50%–9.99%. The MDLs were below 1 mg/kg. These results using the aforementioned methods met the standards of residue analysis. The present study can provide scientific analysis methods and a basis for evaluation of the study of IL residues in environmental samples.

中文翻译：

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测定水和土壤样品中不同阴离子和烷基链长的离子液体的残留浓度

考虑到离子液体（ILs）的广泛合成和应用，ILs的毒性最近已引起越来越多的关注。但是，很少有研究关注环境样品中IL的测定方法。在本研究中，我们使用高效液相色谱（HPLC）和紫外（UV）分光光度法对12种不同化学结构的IL进行了测定。还通过单因素实验和响应面方法（RSM）获得了从土壤样品中提取IL的最佳条件。仪器的检出限（IDL）达到10 ^–10 g。与使用紫外线相比，HPLC的标准曲线具有更强的相关性（R ²≥0.999）和检测下限。因此，我们使用HPLC来检测水和土壤样品中IL的含量。标准添加方法用于上述方法的可靠性测试。水样的平均回收率为90.46％–108.83％，变异系数（CV）为0.51％–9.07％。方法检测限（MDL）低于0.1 mg / L。土壤样品的最佳IL提取条件如下：甲醇与饱和氯化铵之比为90:10，超声时间为50分钟，功率为350W。土壤样品的平均回收率为70.39％–85.30。 ％，CV为0.50％–9.99％。MDL低于1 mg / kg。使用前述方法的这些结果符合残留物分析的标准。