College of Chemistry, Jilin University, Changchun 130012, China.
Talanta. 2011 Oct 15;85(5):2632-8. doi: 10.1016/j.talanta.2011.08.037. Epub 2011 Aug 25.
A simple method based on simultaneous microwave-assisted derivatization and ionic liquid-based dispersive liquid-liquid microextraction (IL-based DLLME) is proposed for the derivatization, extraction and preconcentration of formaldehyde in beverage samples prior to the determination by high-performance liquid chromatography (HPLC). Formaldehyde was in situ derivatized with 2,4-dinitrophenylhydrazine (DNPH) and simultaneously extracted and preconcentrated by using microwave-assisted derivatization and IL-based DLLME in a single step. Several experimental parameters, including type and volume of extraction solvent, type and volume of disperser, microwave power and irradiation time, volume of DNPH, pH of sample solution, and ionic strength were evaluated. When the microwave power was 120 W, formaldehyde could be derivatized and extracted simultaneously only within 90 s. Under optimal experimental conditions, good linearity was observed in the range of 0.5-50 ng/mL with the correlation coefficient of 0.9965, and the limit of detection was 0.12 ng/mL. The proposed method was applied to the analysis of different beverage samples, and the recoveries of formaldehyde obtained were in the range of 84.9-95.1% with the relative standard deviations lower than 8.4%. The results showed that the proposed method was a rapid, convenient and feasible method for the determination of formaldehyde in beverage samples.
本文提出了一种基于同时微波辅助衍生化和离子液体分散液液微萃取（IL-DLLME）的简单方法，用于衍生化、提取和预浓缩饮料样品中的甲醛，然后通过高效液相色谱（HPLC）进行测定。甲醛与 2,4-二硝基苯肼（DNPH）就地衍生化，并通过微波辅助衍生化和 IL-DLLME 在一步中同时提取和预浓缩。评估了几种实验参数，包括萃取溶剂的类型和体积、分散剂的类型和体积、微波功率和辐照时间、DNPH 的体积、样品溶液的 pH 值和离子强度。当微波功率为 120 W 时，甲醛仅在 90 秒内即可同时衍生化和提取。在最佳实验条件下，在 0.5-50 ng/mL 范围内观察到良好的线性关系，相关系数为 0.9965，检出限为 0.12 ng/mL。该方法用于不同饮料样品的分析，甲醛的回收率在 84.9-95.1%范围内，相对标准偏差低于 8.4%。结果表明，该方法是一种快速、方便、可行的测定饮料样品中甲醛的方法。
