建立固相萃取(solid phase extraction，SPE)前处理-高效液相色谱串联二极管阵列和荧光检测器(high performance liquid chromatography with diode array detector/fluorescence detector，HPLC-DAD/FLD)快速检测甜橙汁[l1] [ql2] 中9种多甲氧基黄酮(polymethoxyflavones，PMFs)的方法。橙汁经粗滤后过C18固相萃取柱，依次以超纯水、30%乙腈清洗除杂，乙酸乙酯洗脱，氮气吹干后用甲醇溶解，制得橙汁PMFs样品。以0.05%磷酸、甲醇、50%四氢呋喃为HPLC流动相进行反相梯度洗脱，利用DAD、FLD同时获得各物质的紫外和荧光光谱及峰面积，从而对样品PMFs做定性和定量检测。该条件下，9种PMFs在10 min内实现快速分离。采用外标法定量，紫外检测波长330 nm，荧光激发和发射波长分别为340 nm和450/500 nm，各物质线性关系良好(R2>0.999)，紫外和荧光定量限分别为4.00~61.2 μg/L和0.024~0.61 mg/L(对原果汁)，橙汁PMFs加标回收率为96.4%~104.2%(紫外)和94.2%~102.1%(荧光)，两种检测器定量结果具有良好的一致性。该方法前处理简便、耗时短、成本低，适合橙汁中多甲氧基黄酮成分的快速检测。按本方法对11个汁用甜橙品系鲜榨汁进行了分析，结果显示“渝早橙”PMFs含量最高，具备进一步开发的优良潜力。

A method using solid phase extraction (SPE) for sample preparation and followed with high performance liquid chromatography coupled with diode array detector and fluorescence detector (HPLC-DAD/FLD) analysis was developed to determine 9 polymethoxyflavones (PMFs) compounds in orange juice. Orange juice was filtered and went through a C18 SPE cartridge; the cartridge was washed in series with ultra-pure water and 30% of acetonitrile; the adsorbed components were then eluted with ethyl acetate, dried under nitrogen current and re-dissolved in methanol [l1] [ql2] to produce the PMFs sample. Using 0.05% of phosphoric acid solution, methanol and 50% of tetrahydrofuran as the mobile phase[l3] [ql4] , the sample was separated under gradient elution condition by reverse phase HPLC. Meanwhile, sample PMFs were qualitatively and quantitatively determined using the ultraviolet (UV) and fluorescence (FL) spectra and the peak area obtained by DAD and FLD. All the nine PMFs separated in 10 min under the solvent gradient composed. Using 330 nm for UV quantification, 340 nm and 450/500 nm for FL excitation and emission, the external standard calibration showed good linearity (R2>0.999). The converted limit of quantitation for juice was [l5] 4.00-61.2 μg/L and 0.024-0.61 mg/L respectively for UV and FL signal; recovery study showed good accuracy for both UV (96.4%-104.2%) and FL (94.2%-102.1%) examination; furthermore, UV and FL determination showed well accordance with each other. This method possessed the advantages including simple preparation, short time-consuming and low cost, which enabled it applicable for the rapid determination of PMFs contained in orange juice. As an instance application, fresh squeezed juices from eleven juice-processing sweet orange cultivars were analyzed; the results showed that Yuzaocheng contained the highest amount of PMFs, exhibiting prospective potency for further exploitation.