School of Pharmacy, Shanxi Medical University, Taiyuan, P.R. China.
J Sep Sci. 2017 Jul;40(14):2959-2966. doi: 10.1002/jssc.201700169. Epub 2017 Jun 14.
A novel graphene/dodecanol floating solidification microextraction followed by HPLC with diode-array detection has been developed to extract trace levels of four cinnamic acid derivatives in traditional Chinese medicines. Several parameters affecting the performance were investigated and optimized. Also, possible microextraction mechanism was analyzed and discussed. Under the optimum conditions (amount of graphene in dodecanol: 0.25 mg/mL; volume of extraction phase: 70 μL; pH of sample phase: 3; extraction time: 30 min; stirring rate: 1000 rpm; salt amount: 26.5% NaCl; volume of sample phase: 10 mL, and without dispersant addition), the enrichment factors of four cinnamic acid derivatives ranged from 26 to 112, the linear ranges were 1.0 × 10 -10.0 μg/mL for caffeic acid, 1.3 × 10 -1.9 μg/mL for p-hydroxycinnamic acid, 2.8 × 10 -4.1 μg/mL for ferulic acid, and 2.7 × 10 -4.1 μg/mL for cinnamic acid, with r ≥ 0.9993. The detection limits were found to be in the range of 0.1-1.0 ng/mL, and satisfactory recoveries (92.5-111.2%) and precisions (RSDs 1.1-9.5%) were also achieved. The results showed that the approach is simple, effective and sensitive for the preconcentration and determination of trace levels of cinnamic acid derivatives in Chinese medicines. The proposed method was compared with conventional dodecanol floating solidification microextraction and other extraction methods.
一种新型的石墨烯/十二醇漂浮固化微萃取，随后采用高效液相色谱法与二极管阵列检测，用于提取中草药中四种肉桂酸衍生物的痕量水平。研究并优化了影响性能的几个参数。还分析并讨论了可能的微萃取机制。在最佳条件下（十二醇中石墨烯的量：0.25 mg/mL；萃取相的体积：70 μL；样品相的 pH 值：3；萃取时间：30 min；搅拌速度：1000 rpm；盐量：26.5% NaCl；样品相的体积：10 mL，不加分散剂），四种肉桂酸衍生物的富集因子范围为 26 至 112，线性范围为 1.0×10 -10.0μg/mL 对于咖啡酸，1.3×10 -1.9μg/mL 对羟基肉桂酸，2.8×10 -4.1μg/mL 对阿魏酸，2.7×10 -4.1μg/mL 对肉桂酸，r ≥ 0.9993。检测限在 0.1-1.0 ng/mL 范围内，回收率（92.5-111.2%）和精密度（RSDs 1.1-9.5%）均令人满意。结果表明，该方法简单、有效、灵敏，可用于中草药中肉桂酸衍生物的痕量水平的预浓缩和测定。将该方法与传统的十二醇漂浮固化微萃取和其他萃取方法进行了比较。
