基于脂肪酸的漂浮液滴固化分散液液微萃取-高效液相色谱法联用测定酒类样品中的4-乙基苯酚和4-乙基愈创木酚

建立了基于脂肪酸的漂浮液滴固化分散液液微萃取(FA-DLLME-SFO)方法,与高效液相色谱联用检测了酒类样品中的4-乙基苯酚和4-乙基愈创木酚。该方法萃取时间仅需4 min,仅需脂肪酸、氨水和硫酸3种对环境友好的试剂。对影响方法萃取效率的因素(包括样品的体积、萃取剂的种类和用量、氨水和硫酸的体积以及盐的加入量)进行了详细的考察。在最佳萃取条件下(10 mL样品,100μL辛酸萃取剂,110μL 25%~28%(质量分数)的氨水,0.8 mL 98%(质量分数)的浓硫酸,3.0 g NaCl),4-乙基苯酚和4-乙基愈创木酚在0.02~1.0 mg/L范围内呈良好的线性关系,相关系数分别为0.999 7和0.999 9,相对标准偏差(n=3)分别为6.2%和3.5%,检出限分别为6.33和5.81μg/L,富集倍数分别为79和86。在啤酒和白葡萄酒样品中,加标回收率为81.4%~108.7%,相对标准偏差(n=3)小于8.9%。该方法简单、对环境友好,可用于酒类样品中4-乙基苯酚和4-乙基愈创木酚的检测。

Fatty acid and solidification floating organic drop-based dispersive liquid-liquid microextraction method coupled with high performance liquid chromatography for the determination of 4-ethylphenol and 4-ethylguaiacol in wines

A method of fatty acid and solidification floating organic drop-based dispersive liquid-liquid microextraction (FA-DLLME-SFO) coupled with high performance liquid chromatography to determine 4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG) in wine samples was developed. The method required less than 4 min to extract the two target analytes from wine samples, and only three kinds of eco-friendly solvents including fatty acid, ammonium hydroxide and sulfuric acid were used. The analytical parameters affecting the extraction efficiency including the volumes of the sample, the nature and volumes of the extraction solvent, the volumes of ammonium hydroxide and sulfuric acid, and the amount of salt addition were optimized. Under the optimum conditions (10 mL sample, 100 μL octanoic acid, 110 μL 25%-28% (mass percentage) NH₄OH, 0.8 mL 98% (mass percentage) H₂SO₄, 3.0 g NaCl), the linear ranges were 0.02-1.0 mg/L with correlation coefficients of 0.9997 and 0.9999 for 4-ethylphenol and 4-ethylguaiacol, and the relative standard deviations (RSDs) were 6.2% and 3.5%, respectively. The LODs were 6.33 μg/L and 5.81 μg/L, and the enrichment factors (EFs) were 79 and 86 for 4-ethylphenol and 4-ethylguaiacol, respectively. The present method was applied to the determination of the two analytes in white wine and beer samples, and the recoveries of them were in the range of 81.4%-108.7% with the RSDs less than 8.9%. The method is simple and eco-friendly for rapid analysis of 4-ethylphenol and 4-ethylguaiacol in wine samples.