The comprehensive scan technique using single quadruple GC-MS was introduced and demonstrated in different applications for improving the sensitivity,selectivity,and speed of analysis of multi-compound in complex matr...The comprehensive scan technique using single quadruple GC-MS was introduced and demonstrated in different applications for improving the sensitivity,selectivity,and speed of analysis of multi-compound in complex matrices. This flexible technique includes eight types of scan functions combined with selectable instrument parameters,which gives additional benefits when compared to traditional single full scan or SIM function. The sensitivity of PBDEs especially dece-BDE was improved by using multiple full scan and multiple simultaneous FS/SIM mode;the method development of multi-residue analysis of pesticides in food was simplified using a combination of FS and SIM展开更多
Rare earth(RE)can produce excellent precipitation hardening in Mg alloys.However,when forming a solid solution,it also deteriorates formability,a problem that can usually be overcome by raising deformation temperature...Rare earth(RE)can produce excellent precipitation hardening in Mg alloys.However,when forming a solid solution,it also deteriorates formability,a problem that can usually be overcome by raising deformation temperature.Here we report an unexpected observation of high temperature brittleness in a Mg-Gd-Y-Ag alloy.As the temperature reached 500℃,the formability decreased drastically,leading to severe intergranular fracture under only 0.5% strain.This was caused by failure of grain boundaries,which are weakened by segregated interfacial compounds.展开更多
In this paper,a simple method based on ion chromatography（IC） with conductivity detection was developed for the determination of iminodiacetic acid（IDA） in the herbicide of glyphosate.Under optimized chromatograph...In this paper,a simple method based on ion chromatography（IC） with conductivity detection was developed for the determination of iminodiacetic acid（IDA） in the herbicide of glyphosate.Under optimized chromatographic conditions,good linear relationship,sensitivity and reproducibility were obtained.The detection limit（LOD） for IDA obtained by injecting 25 μL of sample was 31.8 μg/L（S/N = 3）.Relative standard deviation（RSD） of repeated analysis for the peak areas was less than 1.53%（n = 6）.A spiking study was performed with satisfactory recoveries between 92.8%and 103.6%.It was confirmed that this method could be applied in glyphosate products.展开更多
This study describes a novel application of ion chromatography coupled with post-column photochemically induced fluorimetry derivatisation in alkaline medium and fluorescence detection （IC-hv-FD） for the determinati...This study describes a novel application of ion chromatography coupled with post-column photochemically induced fluorimetry derivatisation in alkaline medium and fluorescence detection （IC-hv-FD） for the determination of neonicotinoid pesticide, thiacloprid. In an aqueous medium, this compound showed fluorescence with an excitation maximum at 236 nm and an emission maximum at 353 nm. The 10 mmol/L NaOH with 10% （v/v） acetonitrile solution pumped at flow rate of 1.0 mL/min was used for the chromatographic elution to isocratically separate thiacloprid on an Ion Pac~＇ AS 11 （250 mm x 4 mm i.d; 13 p^m particle size, Dionex） anion-exchange column. The linear concentration range of application was 0.04-10.0 mg]L, with a relative standard deviation （RSD, n = 7） of 1.7% （for a level of 2.0 mg/L） and detection limit （LOD, SiN = 3） of 9.9 p^g]L. The procedure was applied with satisfactory results to the analysis of thiacloprid in ground and lake water samples. Pesticide average spiked recoveries ran^ed between 95.5% and 114.0%.展开更多
文摘The comprehensive scan technique using single quadruple GC-MS was introduced and demonstrated in different applications for improving the sensitivity,selectivity,and speed of analysis of multi-compound in complex matrices. This flexible technique includes eight types of scan functions combined with selectable instrument parameters,which gives additional benefits when compared to traditional single full scan or SIM function. The sensitivity of PBDEs especially dece-BDE was improved by using multiple full scan and multiple simultaneous FS/SIM mode;the method development of multi-residue analysis of pesticides in food was simplified using a combination of FS and SIM
基金supported by National Natural Science Foundation of China(Grant numbers 52071178,51901103,51931003,51601003,51401172)the National Key Research and Development Program of China(Grant number 2017YFA0204403)Project of Natural Science Foundation of Heilongjiang Province(grant number LH2019E080)。
文摘Rare earth(RE)can produce excellent precipitation hardening in Mg alloys.However,when forming a solid solution,it also deteriorates formability,a problem that can usually be overcome by raising deformation temperature.Here we report an unexpected observation of high temperature brittleness in a Mg-Gd-Y-Ag alloy.As the temperature reached 500℃,the formability decreased drastically,leading to severe intergranular fracture under only 0.5% strain.This was caused by failure of grain boundaries,which are weakened by segregated interfacial compounds.
基金supported by the National Important Project on Science Instrument(No.2012YQ09022903)Zhejiang Provincial Natural Science Foundation of China(No. Y4110532)Zhejiang Provincial Assay Foundation of China (No.2012C37038)
文摘In this paper,a simple method based on ion chromatography（IC） with conductivity detection was developed for the determination of iminodiacetic acid（IDA） in the herbicide of glyphosate.Under optimized chromatographic conditions,good linear relationship,sensitivity and reproducibility were obtained.The detection limit（LOD） for IDA obtained by injecting 25 μL of sample was 31.8 μg/L（S/N = 3）.Relative standard deviation（RSD） of repeated analysis for the peak areas was less than 1.53%（n = 6）.A spiking study was performed with satisfactory recoveries between 92.8%and 103.6%.It was confirmed that this method could be applied in glyphosate products.
基金financially supported by the Major National Scientific Instrument and Equipment Development Special of China (No. 2012YQ09022903)
文摘This study describes a novel application of ion chromatography coupled with post-column photochemically induced fluorimetry derivatisation in alkaline medium and fluorescence detection （IC-hv-FD） for the determination of neonicotinoid pesticide, thiacloprid. In an aqueous medium, this compound showed fluorescence with an excitation maximum at 236 nm and an emission maximum at 353 nm. The 10 mmol/L NaOH with 10% （v/v） acetonitrile solution pumped at flow rate of 1.0 mL/min was used for the chromatographic elution to isocratically separate thiacloprid on an Ion Pac~＇ AS 11 （250 mm x 4 mm i.d; 13 p^m particle size, Dionex） anion-exchange column. The linear concentration range of application was 0.04-10.0 mg]L, with a relative standard deviation （RSD, n = 7） of 1.7% （for a level of 2.0 mg/L） and detection limit （LOD, SiN = 3） of 9.9 p^g]L. The procedure was applied with satisfactory results to the analysis of thiacloprid in ground and lake water samples. Pesticide average spiked recoveries ran^ed between 95.5% and 114.0%.
