Department of Food Science, Udine University, Via Sondrio 2/A, 33100 Udine, Italy.
Food Chem. 2012 Dec 15;135(4):2687-93. doi: 10.1016/j.foodchem.2012.07.057. Epub 2012 Jul 17.
In this work, a rapid and reliable purification method based on a single mixed solid phase extraction (SPE) column, for the determination of acrylamide in roasted coffee by liquid chromatography-tandem mass spectrometry, was developed. Deuterium labelled d(3)-acrylamide was used as internal standard. Acrylamide was extracted by 10 mL of water and the extract purified by a single SPE column consisting of 0.5 g of an in-house prepared mixture of C18, strong cation (SCX) and anion exchange (SAX) sorbents in the ratio 2/1.5/1.5 (w/w/w). The amount of the three sorbents was optimised in order to eliminate the main interfering compounds present in coffee extracts, such as melanoidins, trigonelline, chlorogenic acids and caffeine. The SPE procedure was very simple and consisted of pushing 1 mL of an aqueous coffee extract through the SPE column followed by 1 mL of water which was collected for the analysis. The method was tested on six samples of roasted coffee of different composition and roasting level. The repeatability of the method, expressed as relative standard deviation (n=6), was lower than 5%. The recovery of acrylamide at three spiked levels ranged from 92% to 95%. The limits of detection (LOD) and quantitation (LOQ) were 5 and 16 μg kg(-1), respectively.
本工作开发了一种基于单根混合固相萃取（SPE）柱的快速可靠的纯化方法，用于通过液相色谱-串联质谱法测定烤咖啡中的丙烯酰胺。使用氘代 d(3)-丙烯酰胺作为内标。丙烯酰胺通过 10 mL 水提取，然后通过一根由 0.5 g 自制的 C18、强阳离子（SCX）和阴离子交换（SAX）吸附剂以 2/1.5/1.5（w/w/w）的比例组成的 SPE 柱进行纯化。优化了三种吸附剂的用量，以消除咖啡提取物中存在的主要干扰化合物，如类黑素、葫芦巴碱、绿原酸和咖啡因。SPE 程序非常简单，包括将 1 mL 水性咖啡提取物通过 SPE 柱，然后再收集 1 mL 水进行分析。该方法在六种不同成分和烘焙水平的烤咖啡样品上进行了测试。方法的重复性（n=6）表示为相对标准偏差，低于 5%。在三个加标水平下，丙烯酰胺的回收率在 92%至 95%之间。检测限（LOD）和定量限（LOQ）分别为 5 和 16 μg kg(-1)。
