基于金属-有机骨架材料的分散固相萃取法测定果汁饮料中的5种植物生长调节剂含量

Determination of 5 Plant Growth Regulators in Juice with MIL-101 Based Dipersive Solid Extraction Coupled to High Performance Liquid Chromatography

建立了同时测定果汁中5种植物生长调节剂(PGRs)的分散固相萃取-高效液相色谱-荧光检测(HPLC-FLD)分析方法。采用水热法合成金属-有机骨架(MOF)材料MIL-101粒子,并用MIL-101作为吸附剂,分散固相萃取样品中5种PGRs。优化的最佳萃取条件为:每10mL样品溶液(调节pH=6)加入10mg吸附剂,萃取时间6min,0.8mL甲醇解吸。样品经Eclipse XDB-C8色谱柱分离,在激发波长280nm、发射波长340nm下进行荧光检测。结果表明,5种植物生长调节剂在线性范围内相关系数均大于0.9980;方法的检出限以信噪比(S/N)≥3计为0.07~0.25μg/L,加标回收率为88.4%~103.8%,相对标准偏差(RSDs)为2.7%~5.1%。该方法选择性好、灵敏度高、重现性好、准确度高,适用于果汁中PGRs的测定。

A method was developed for simultaneous determination of 5 plant growth regulators（PGRs） in juice samples by dispersive solid-phase extraction coupled to high performance liquid chromatography with fluorescence detection（HPLC-FLD）. The metal-organic framework（MOF） materials of MIL-101 were prepared through hydrothermal method, and the obtained MIL-101 particles were used as solid- phase extraction absorbents. The optimal extraction conditions were as follows,the sample matrices were adjusted at pH 6;10 mg MIL-101 particles were used to 10 mL of samples each;the extraction time was 6 rain;0.8 mL of methanol was used for desorption. The extracted PGRs were separated on an Eclipse XDB-C8 column and detected with Xex=280 nm and 入em =340 nm. The good linearity were obtained for 5 PGRs at a concentration range of 1-100μg/L with r〉0. 9980. The limits of detection for 5 PGRs were in the range of 0. 07-0. 25 μg/L with signal to noise ratio（S/N）≥3. The recoveries of PGRs in juice samples at three spiked levels were in the range of 88.4%-103.80% with the relative standard deviations of 2.7 % - 5.1 %. The results demonstrated that the method was suitable for the determination of PGRs in juice samples with high selectivity, sensitivity, accuracy and reproducibility.