Pesticide residues in fruit and vegetables have become a major concern associated with chemical food safety issues. Translocation of pesticides in tomato, mango and pineapple fruits in locally produced samples was inv...Pesticide residues in fruit and vegetables have become a major concern associated with chemical food safety issues. Translocation of pesticides in tomato, mango and pineapple fruits in locally produced samples was investigated using gas chromatography/mass spectrophotometer （GC/MS） procedures. Samples were fractionated with respect to distance from the skin to the core and prepared for analysis. Results showed that organochlorine, organophosphate and synthetic pyrethroid residues were translocated in all fruit samples analyzed. With respect to tomato fractions, the peels retained more residues compared to the pulp and the central core. In the chemical species, organochlorines were retained more in the peels of tomato than the other fractions of the fruit. More organophosphate and organochlorine residues were detected in pineapple peels compared to the pulp. Synthetic pyrethroid residues were evenly distributed in the pineapple fruit. In mangoes, the pulp retained more chemical residues than other fractions of the fruit. More organochlorine residues were retained in the pulp of mango than in the other fractions of the fruit. Synthetic pyrethroid residues were evenly distributed throughout the mango fruit. All the chemical species identified were translocatable across the fractional parts of all the fruits. There were significant differences in translocation and residue accumulation of pesticides among the fractional parts of all samples.展开更多
本实验以菠萝蜜果皮的黄酮粗提液为供试液,通过静态吸附解析从6种极性不同的大孔树脂中筛选出NKA树脂作为最佳分离纯化树脂,并对NKA柱层析的动态吸附解析条件进行探索,得到最佳上样浓度为0.90 mg/m L、上样体积为200 m L、洗脱剂用量为1...本实验以菠萝蜜果皮的黄酮粗提液为供试液,通过静态吸附解析从6种极性不同的大孔树脂中筛选出NKA树脂作为最佳分离纯化树脂,并对NKA柱层析的动态吸附解析条件进行探索,得到最佳上样浓度为0.90 mg/m L、上样体积为200 m L、洗脱剂用量为120 m L;通过柱层析的单因素和正交实验,得到最佳纯化工艺为:上样流速和洗脱流速4 m L/min,上样p H5,以70%乙醇洗脱,此条件下,黄酮回收率高达96.02%;过柱后样品的黄酮纯度由原来的16.74%提高到84.42%,提高了4.04倍,表明NKA树脂对菠萝蜜果皮黄酮的富集纯化效果显著。对比纯化前后黄酮的体外抗氧化活性,结果表明,经NKA柱层析后,随着黄酮纯度提高,样品的体外抗氧化活性也显著提高。展开更多
文摘Pesticide residues in fruit and vegetables have become a major concern associated with chemical food safety issues. Translocation of pesticides in tomato, mango and pineapple fruits in locally produced samples was investigated using gas chromatography/mass spectrophotometer （GC/MS） procedures. Samples were fractionated with respect to distance from the skin to the core and prepared for analysis. Results showed that organochlorine, organophosphate and synthetic pyrethroid residues were translocated in all fruit samples analyzed. With respect to tomato fractions, the peels retained more residues compared to the pulp and the central core. In the chemical species, organochlorines were retained more in the peels of tomato than the other fractions of the fruit. More organophosphate and organochlorine residues were detected in pineapple peels compared to the pulp. Synthetic pyrethroid residues were evenly distributed in the pineapple fruit. In mangoes, the pulp retained more chemical residues than other fractions of the fruit. More organochlorine residues were retained in the pulp of mango than in the other fractions of the fruit. Synthetic pyrethroid residues were evenly distributed throughout the mango fruit. All the chemical species identified were translocatable across the fractional parts of all the fruits. There were significant differences in translocation and residue accumulation of pesticides among the fractional parts of all samples.
文摘本实验以菠萝蜜果皮的黄酮粗提液为供试液,通过静态吸附解析从6种极性不同的大孔树脂中筛选出NKA树脂作为最佳分离纯化树脂,并对NKA柱层析的动态吸附解析条件进行探索,得到最佳上样浓度为0.90 mg/m L、上样体积为200 m L、洗脱剂用量为120 m L;通过柱层析的单因素和正交实验,得到最佳纯化工艺为:上样流速和洗脱流速4 m L/min,上样p H5,以70%乙醇洗脱,此条件下,黄酮回收率高达96.02%;过柱后样品的黄酮纯度由原来的16.74%提高到84.42%,提高了4.04倍,表明NKA树脂对菠萝蜜果皮黄酮的富集纯化效果显著。对比纯化前后黄酮的体外抗氧化活性,结果表明,经NKA柱层析后,随着黄酮纯度提高,样品的体外抗氧化活性也显著提高。
