A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） ...A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） coupled with high performance liquid chromatography-diode array detector （HPLC-DAD）. Some experimental parameters that influence the extraction efficiency were studied and optimized to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 5 to 1000 ng mL^-1 for all the five carbamate pesticides, with the correlation coefficients （r^2） varying from 0.9984 to 0.9994. Good enrichment factors were achieved ranging from 80 to 177- fold, depending on the compound. The limits of detection （LODs） （S/N = 3） were ranged from 0.1 to 0.5 ng mL^-1. The method has been successfully applied to the analysis of the pesticide residues in environmental water samples.展开更多
Leaves of Ziziphus jujuba Mill.（Z. jujuba） were used as a folk medicine to treat children suffering from typhoid fever, furuncle and ecthyma in China. The present study was to establish a high performance liquid chr...Leaves of Ziziphus jujuba Mill.（Z. jujuba） were used as a folk medicine to treat children suffering from typhoid fever, furuncle and ecthyma in China. The present study was to establish a high performance liquid chroma- tography-diode array detector（HPLC-DAD） method for quality control of Z. jujuba leaves. The validated method was applied to the simultaneous characterization and quantification of sixteen main constituents in thirty samples, which comprised the whole life stage of Z. ]ujuba leaves from six cultivars in Yulin, Shannxi Province, China. HPLC fin- gerprint file of Z. jujuba leaves was set up and the results indicate that the major constituents of Z. jujuba leaves are （-）-catechin（1）, quercetin-3-O-robinobioside（3）, rutin（4） and quercetin-3-O-a-L-arabinosyl-（1---~2）-a-L-rhamnoside（6） with the total contents of the nine flavonoids in respective batch ranging from 18.52 mg/g to 39.51 mg/g. In addition, the contents of compounds depend on both the season and the cultivar. During ripening of Z. jujuba leaves, flavo- noids of all the cultivars present a similar trend： initially decrease from 25th, Jun. to 5th, Aug., 2015, and then in- crease for a period of time, finally slightly fluctuate on 5th Oct. The highest contents of total flavonoids were regis- tered on 25th Jun., 2015. Different cultivars have 50%--90% variation on the content for the three classes of com- pounds. Taken together, the results demonstrate that Z. jujuba leaves have great potential to be a new health-promoting resource based on flavonoids and the best sampling time of them is in June.展开更多
According to the General Office of the State Council of China, tree peony seeds（TPSs, Paeonia suffruticosa Andr.） are considered an emerging source for edible oil. In Chinese folk medicine, TPSs are used for allevia...According to the General Office of the State Council of China, tree peony seeds（TPSs, Paeonia suffruticosa Andr.） are considered an emerging source for edible oil. In Chinese folk medicine, TPSs are used for alleviating waist and leg pain. In the present study, a simple, accurate and rapid fingerprint method based on high performance liquid chromatography with diode array detection（HPLe-DAD） was developed and validated to quantify the profiles of ten representative compounds in TPSs. All standard calibration curves exhibited good linearity（R2〉0.9995） in the I-IPLC-DAD analysis. The recovery of the standards ranged from 96.37% to 102.10%. The results show that stilbe- noids are the major constituents in TPSs, and their total content ranges from 25.71 mg/g to 54.03 mg/g. Suffruticosol A, suffruticosol B, trans-e-viniferm, ampelopsin E and paeoniflorin are the major components in methanol- water（80：20, volume ratio） extracts with average contents of 3.962, 12.264, 5.826, 14.060 and 12.755 rag/g, respec- tively. Additionally, 14 batches of seeds collected from different regions were used to establish a reference fingerprint Their similarity values were higher than 0.944 except for the sample（0.863） from Linxia. These results collectively indicate that the quantitative HPLC fingerprint method can serve as a prerequisite quality control for TPSs, and is a promising resource for developing new herbal or food products.展开更多
基金supported both by the Natural Science Foundations of Hebei(No.B2008000210)the Scientific Research Foundation of Agricultural University of Hebei.
文摘A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） coupled with high performance liquid chromatography-diode array detector （HPLC-DAD）. Some experimental parameters that influence the extraction efficiency were studied and optimized to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 5 to 1000 ng mL^-1 for all the five carbamate pesticides, with the correlation coefficients （r^2） varying from 0.9984 to 0.9994. Good enrichment factors were achieved ranging from 80 to 177- fold, depending on the compound. The limits of detection （LODs） （S/N = 3） were ranged from 0.1 to 0.5 ng mL^-1. The method has been successfully applied to the analysis of the pesticide residues in environmental water samples.
文摘Leaves of Ziziphus jujuba Mill.（Z. jujuba） were used as a folk medicine to treat children suffering from typhoid fever, furuncle and ecthyma in China. The present study was to establish a high performance liquid chroma- tography-diode array detector（HPLC-DAD） method for quality control of Z. jujuba leaves. The validated method was applied to the simultaneous characterization and quantification of sixteen main constituents in thirty samples, which comprised the whole life stage of Z. ]ujuba leaves from six cultivars in Yulin, Shannxi Province, China. HPLC fin- gerprint file of Z. jujuba leaves was set up and the results indicate that the major constituents of Z. jujuba leaves are （-）-catechin（1）, quercetin-3-O-robinobioside（3）, rutin（4） and quercetin-3-O-a-L-arabinosyl-（1---~2）-a-L-rhamnoside（6） with the total contents of the nine flavonoids in respective batch ranging from 18.52 mg/g to 39.51 mg/g. In addition, the contents of compounds depend on both the season and the cultivar. During ripening of Z. jujuba leaves, flavo- noids of all the cultivars present a similar trend： initially decrease from 25th, Jun. to 5th, Aug., 2015, and then in- crease for a period of time, finally slightly fluctuate on 5th Oct. The highest contents of total flavonoids were regis- tered on 25th Jun., 2015. Different cultivars have 50%--90% variation on the content for the three classes of com- pounds. Taken together, the results demonstrate that Z. jujuba leaves have great potential to be a new health-promoting resource based on flavonoids and the best sampling time of them is in June.
文摘According to the General Office of the State Council of China, tree peony seeds（TPSs, Paeonia suffruticosa Andr.） are considered an emerging source for edible oil. In Chinese folk medicine, TPSs are used for alleviating waist and leg pain. In the present study, a simple, accurate and rapid fingerprint method based on high performance liquid chromatography with diode array detection（HPLe-DAD） was developed and validated to quantify the profiles of ten representative compounds in TPSs. All standard calibration curves exhibited good linearity（R2〉0.9995） in the I-IPLC-DAD analysis. The recovery of the standards ranged from 96.37% to 102.10%. The results show that stilbe- noids are the major constituents in TPSs, and their total content ranges from 25.71 mg/g to 54.03 mg/g. Suffruticosol A, suffruticosol B, trans-e-viniferm, ampelopsin E and paeoniflorin are the major components in methanol- water（80：20, volume ratio） extracts with average contents of 3.962, 12.264, 5.826, 14.060 and 12.755 rag/g, respec- tively. Additionally, 14 batches of seeds collected from different regions were used to establish a reference fingerprint Their similarity values were higher than 0.944 except for the sample（0.863） from Linxia. These results collectively indicate that the quantitative HPLC fingerprint method can serve as a prerequisite quality control for TPSs, and is a promising resource for developing new herbal or food products.
