Department of Analytical Chemistry, Faculty of Sciences. University of Córdoba, E-14004 Córdoba, Spain.
Talanta. 1998 Aug;46(5):1123-30. doi: 10.1016/s0039-9140(97)00375-5.
A clean, highly selective supercritical fluid extraction (SFE) method for the isolation of phenols from olive leaf samples was examined. Total phenol extracts were determined using the Folin-Ciocalteu reagent. Dried, ground, sieved olive leaf samples (30 mg) are subjected to SFE, using carbon dioxide modified with 10% methanol at 334 bar, 100 degrees C (CO(2) density 0.70 g ml(-1)) at a liquid flow-rate of 2 ml min(-1) for 140 min. Diatomaceous earth is used to reduce the void volume of the extraction vessel. The influence of extraction variables such as modifier content, pressure, temperature, flow-rate, extraction time, and collection/elution variables, were studied. Supercritical fluid extracts were screened for acid compounds such as carboxylic acids and phenols using Electrospray-MS (in the negative ionization mode). SFE was found to produce higher phenol recoveries than sonication in liquid solvents such as n-hexane, diethyl ether and ethyl acetate. However, the extraction yield obtained was only 45%, using liquid methanol.
一种从橄榄叶样品中分离酚类物质的清洁、高选择性超临界流体萃取（SFE）方法进行了研究。使用福林-肖卡（Folin-Ciocalteu）试剂测定总酚提取物。将干燥、粉碎、过筛的橄榄叶样品（30mg）在 334 巴、100°C（CO2 密度为 0.70g/ml）下，用 10%甲醇改性的二氧化碳进行 SFE，液体流速为 2ml/min，萃取时间为 140min。硅藻土用于减少萃取容器的空隙体积。研究了萃取变量（如改性剂含量、压力、温度、流速、萃取时间）和收集/洗脱变量对萃取的影响。使用电喷雾质谱（负离子模式）对超临界流体提取物中的酸类化合物（如羧酸和酚类）进行了筛选。与在正己烷、乙醚和乙酸乙酯等液体溶剂中进行超声提取相比，SFE 可产生更高的酚类回收率。然而，使用液体甲醇时，提取率仅为 45%。
