基于QuEChERS-气相色谱-质谱法快速检测滇红茶中香茅醇和香叶醇

Quick Detection of Citronellol and Geraniol in Yunnan Black Tea by QuEChERS-GC-MS

摘要:

【目的】针对滇红茶中可能非法添加玫瑰香精（香茅醇、香叶醇）的问题，建立了QuEChERS-气相色谱-质谱法（QuEChERS-GC-MS），用于快速检测香茅醇和香叶醇。【方法】滇红茶样品用水浸润后再经乙腈提取，提取液用QuEChERS分散固相进行萃取净化，在选择离子监测（SIM）模式下检测，并通过外标法定量。【结果】香茅醇、香叶醇在质量浓度为0.05~5.00 μg/mL时线性关系良好，相关系数（R²）均大于0.999；加标水平为0.5、1.0、5.0、10.0 mg/kg时，回收率为95.7%~106.4%，相对标准偏差（RSD）为0.77%~6.58%，方法的检出限（LOD）分别为0.22、0.10 mg/kg，定量限（LOQ）分别为0.74、0.32 mg/kg。对29批可疑的滇红茶样品进行分析检测，结果表明，所有可疑样品中均检出较高质量分数的香茅醇和香叶醇，最高质量分数分别为53.40、68.33 mg/kg，滇红茶中可能存在非法添加香精的情况。【结论】该方法简单易操作，重复性和精密度良好，适用于滇红茶中香茅醇和香叶醇的快速检测。

Abstract:

[Objective] In view of the possible illegal addition of rose flavors (citronellol and geraniol) to Yunnan black tea, a method was established for rapid detection of citronellol and geraniol based on QuEChERS-gas chromatography-mass spectrometry (QuEChERS-GC-MS). [Method] >The procedure involved extracting Yunnan black tea samples with acetonitrile following water wetting. The extract was purified by QuEChERS dispersed solid phase extraction. It was detected under the selected ion monitoring (SIM) mode and quantified by the external standard method. [Result] Good linear relationships were observed for citronellol and geraniol within the mass concentration range from 0.05 to 5.00 μg/mL, with correlation coefficients (R²) greater than 0.999 for both compounds. The recovery rates under the spiked concentrations of 0.5, 1.0, 5.0, and 10.0 mg/kg fell within the range of 95.7% to 106.4%, with relative standard deviations (RSD) ranging from 0.77% to 6.58%. The method exhibited the limits of detection (LOD) of 0.22 mg/kg and 0.10 mg/kg and the limits of quantification (LOQ) of 0.74 mg/kg and 0.32 mg/kg. The method was then employed to analyze 29 suspected Yunnan black tea samples. The results showed high mass fractions of citronellol and geraniol in suspected samples, with the highest mass fractions recorded at 53.40 mg/kg and 68.33 mg/kg, respectively, which indicated illegal addition of flavors in Yunnan black tea. [Conclusion] It is a straightforward, reproducible, and precise method suitable for the rapid detection of citronellol and geraniol in Yunnan black tea.