Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, 1500 Research Parkway Ste A120, Texas A&M University, College Station, TX 77845, USA.
Talanta. 2011 Jan 15;83(3):948-54. doi: 10.1016/j.talanta.2010.10.063. Epub 2010 Nov 5.
Rapid analytical method for the simultaneous separation and determination of amines and organic acids is a vital interest for quality control of citrus and their products. In the present study, a simultaneous high performance liquid chromatography (HPLC) method for the rapid separation of three amines and two organic acids was developed. Chromatographic separation of compounds was achieved using Xbridge C(18) column at ambient temperature, with an isocratic mobile phase of 3mM phosphoric acid at a flow rate of 1.0 mL min(-1). A photodiode array (PDA) detector was used to monitor the eluent at 223 nm and 254 nm with a total analysis time of 10 min. Extraction of amines and organic acids from citrus juice was optimized. The method was validated by tests of linearity, recovery, precision and ruggedness. The limit of detection (LOD) and limit of quantification (LOQ) for amines and ascorbic acid were determined to be 5 ng and 9.8 ng, respectively. All calibration curves showed good linearity (R(2) ≥ 0.9999) within the test ranges. The recoveries of the amines and organic acids ranged between 84% and 117%. The identity of each peak was confirmed by mass spectral (MS) analysis. The developed method was successfully applied to analyze the content of amines and organic acids in six different species and two varieties of citrus. Results indicate that mandarin and Marrs sweet orange contain high level of amines, while pummelo and Rio Red grapefruit had high content of ascorbic acid (137-251 μg mL(-1)) and citric acid (5-22 mg mL(-1)). Synephrine was the major amine present in Clementine (114 μg mL(-1)) and Marrs sweet orange (85 μg mL(-1)). To the best of our knowledge, this is the first report on simultaneous separation and quantification of amines and organic acids in Marrs sweet orange, Meyer lemon, Nova tangerine, Clementine, Ugli tangelo and Wekiwa tangelo.
用于同时分离和测定胺类和有机酸的快速分析方法是柑橘及其制品质量控制的重要研究内容。本研究建立了一种同时分离三种胺类和两种有机酸的高效液相色谱（HPLC）方法。在室温下，采用 Xbridge C（18）色谱柱，以 3mM 磷酸为等度流动相，流速为 1.0 mL/min，实现了化合物的色谱分离。采用光电二极管阵列（PDA）检测器，在 223nm 和 254nm 处监测洗脱液，总分析时间为 10min。优化了从柑橘汁中提取胺类和有机酸的方法。通过线性、回收率、精密度和稳健性试验对该方法进行了验证。胺类和抗坏血酸的检测限（LOD）和定量限（LOQ）分别为 5ng 和 9.8ng。所有校准曲线在测试范围内均具有良好的线性（R（2）≥0.9999）。胺类和有机酸的回收率在 84%~117%之间。通过质谱（MS）分析确认了每个峰的特征。该方法成功地应用于分析六种不同种类和两个品种的柑橘中胺类和有机酸的含量。结果表明，温州蜜柑和 Marrs 甜橙含有高水平的胺类，而葡萄柚和红肉葡萄柚含有高含量的抗坏血酸（137-251μg/mL）和柠檬酸（5-22mg/mL）。辛弗林是克莱门氏小柑橘（114μg/mL）和 Marrs 甜橙（85μg/mL）中主要的胺类。据我们所知，这是首次同时分离和定量 Marrs 甜橙、酸橙、Nova 甜橙、克莱门氏小柑橘、葡萄柚和 Wekiwa 橘柚中胺类和有机酸的报道。
