简介:沙棘籽油样品经微波消解处理,采用电感耦合等离子体质谱法测定所得样品溶液中铁、硒、锌、钾、钠、钙、镁、铜、锰、铅、砷、汞、镉等13种微量元素的含量。使用动态反应池技术消除了多原子离子对部分被测元素的干扰。方法快速准确、灵敏度高,加标回收率在95.5%~102.8%之间,相对标准偏差小于3%。
简介:沙棘果油样品经微波消解处理,采用电感耦合等离子体质谱法测定所得样品溶液中铁、硒、锌、钾、钠、钙、镁、铜、锰、铅、砷、汞、镉等13种微量元素的含量。使用动态反应池技术消除了多原子离子对部分被测元素的干扰。方法快速准确、灵敏度高,加标回收率在96.1%~101%之间,相对标准偏差小于3%。
简介:Fivehumicfractionswereobtainedfromauniformly^15N-labelledsoilbyextractionwith0.1molL^-1Na4P2O7,0.1molL^-1NaOH,andHF/HCl-0.1molL^-1NaOH,consecutively,andanalyzedby^13Cand^15NCPMASNMR(crosspolarizationandmagicanglespinningnuclearmagneticresonace).Comparedwiththoseofnativesoilshumicfractionsstudiedasawholecontainedmorealkyls,methoxylsandO-alkyls,being27%-36%,17%-21%and36%-40%,respectively,butfeweraromaticsandcarboxyls(bein14%-20%and13%-90%,respectively),Amongthosehumicfractions,thehumicacid(HA)andfulvicacid(FA)extractedby0.1molL^-1Na4P2O7containedslightlymorecarboxylsthancorrespondinghumicfractionsextractedby0.1molL^-1NaOH,andtheHAextactedby0.1molL^-1NaOHaftertreatmentwithHF/HClcontainedtheleastaromaticsandcarboxyls.Thedistributionofnitrogenfunctionalgroupsofsoilhumicfractionsstudiedwasquitesimilartoeachotherandalsoquitesimilartothatofhumicfractionfromnativesoils.Morethan75%oftotalNineachfractionwasinamidefrom,with9%-13%presentasaromaticand/oraliphaticaminesandtheremainderasheerocyclicN.
简介:Theannualseriesofδ13CweremeasuredintreeringsofthreeCryptomeriafortuneidisks(CF-1,CF-2,andCF-3)collectedfromWestTianmuMountain,ZhejiangProvince,China,accordingtocross-datingtreeringages.Therewasnoobviousdecreasingtrendoftheδ13CannualtimeseriesofCF-2before1835.However,from1835to1982thethreetreeringδ13Cannualseriesexhibitedsimilardecreasingtrendsthatweresignificantly(P≤0.001)correlated.Thedistributioncharacteristicsofascatterdiagrambetweenestimatedδ13CseriesofCF-2frommodelingandtheatmosphericCO2concentrationextractedfromtheLawDomeicecorefrom1840to1978wereanalyzedandacurvilinearregressionequationforreconstructingatmosphericCO2concentrationwasestablishedwithR2=0.98.Also,atestofindependentsamplesindicatedthatbetween1685and1839thereconstructedatmosphericCO2concentrationusingtheδ13CseriesofCF-2hadacloserelationshipwiththeLawDomeandSipleicecores,withastandarddeviationof1.98.ThegeneralincreasingtrendofthereconstructedatmosphericCO2concentrationcloselyreflectedthelong-termvariationofatmosphericCO2concentrationrecordedbothbeforeandaftertheIndustrialRevolution.Between1685and1840theevaluatedatmosphericCO2concentrationwasstable,butafter1840itexhibitedarapidincrease.Givenalongerδ13Cannualtimeseriesoftreerings,itwasfeasibletorebuildarepresentativetimeseriestodescribetheatmosphericCO2concentrationforanearlierperiodandforyearsthatwerenotintheicecorerecord.
简介:沙棘维生素P粉样品经微波消解处理,采用电感耦合等离子体质谱法测定样品中铁、硒、锌、钾、钠、钙、镁、铜、锰、铅、砷、汞、镉等13种微量元素的含量。使用动态反应池技术消除了多原子离子对部分被测元素的干扰。方法快速准确、灵敏度高,加标回收率在95.2%~101.8%之间,相对标准偏差小于3.0%。