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翻译一段化学类英语~
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| A rapid and reliable analytical method is presented for the determination of trace amounts of benzo[a]pyrene（苯并[a]芘） in roasted coffee, coffee brew, and spent grounds. Roasted coffee and spent grounds were extracted with acetone, followed by saponification and cyclohexane extraction. Coffee brew was extracted three times with cyclohexane, and the combined extracts were purified by chromatography on a silica gel column. The extracts were analyzed by HPLC with a 5-pm Vydac reversed-phase 201 TPB 5 column and fluorescence detection under isocratic conditions. The benzo[a]pyrene levels in 55 roasted coffee samples, commercially available in The Netherlands, ranged from not detectable (<0.1 pg/kg) to 0.5 bg/kg. Coffee brews were prepared by two different methods from an over-roasted coffee sample with an elevated benzo[a]pyrene level of 2 pg/kg. These brews yielded benzo[a]pyrene contents of approximately 1 ng/L, indicating benzo[a]pyrene extraction yields of about 1% for both coffee preparation methods. |
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铁杆木虫 (著名写手)
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carloslangel(金币+19): 2010-03-01 20:13
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这里展现了一个快速可信赖的检测烘烤咖啡豆，调制咖啡和咖啡残渣里痕量的benzo[a]pyrene的分析方法。烘烤的咖啡豆和咖啡残渣用丙酮萃取，皂化后用环己烷萃取。调制咖啡用环己烷萃取3遍，合并萃取液后用硅胶柱色谱提纯。萃取物用高效液相色谱分析，采用5pm Vydac 反相 201 TPB 5 柱，荧光监测，梯度洗脱。 55个烘烤咖啡（荷兰生产）样品中benzo[a]pyrene的含量从小于0.1pg每公斤到0.5g每公斤。用两种方法制备的过度烘烤的调制咖啡样品中 benzo[a]pyrene的含量提高了2pg每公斤。从这些调制咖啡所得到的 benzo[a]pyrene的含量约为1ng每升，这表明通过两种制备方法得到的 调制咖啡内benzo[a]pyrene大概都为1% roasted coffee指的是烘烤的咖啡豆磨的咖啡粉 coffee brew指的是用咖啡粉煮得的咖啡 spent grounds指的是调制完咖啡剩下的咖啡粉残渣 |
2楼2010-03-01 19:55:39