原子吸收光谱法测定砖茶和花茶中锌和铁的含量分析研究 材料学专业VIP免费

原子吸收光谱法测定砖茶和花茶中锌和铁的含量摘要：为了解青砖茶和茉莉花茶中锌和铁元素的含量及其茶水中元素含量的变化本研究采用微波消解方法处理茶叶，用火焰原子吸收光谱法测定茶叶中锌和铁的含量，同时对两种茶水中锌和铁的含量随时间的变化也进行了一番研究探讨。结果表明，同种元素在不同种茶叶中含量有一定差别，青砖茶中锌含量为120.93mg/kg，铁含量为849.50mg/kg，茉莉花茶中锌含量为66.13mg/kg，铁含量为236.33mg/kg。本实验方法锌的回收率为87.00%~116.83%，铁的回收率为95.13%~118.17%，回收率范围在80%~120%之间，相对标准偏差不超过5.1031%,该方法准确度良好。砖茶中锌、铁离子最大溶出率分别为14.39%、2.49%，花茶中锌、铁离子最大溶出率分别为40.83%、8.96%，说明不同种元素在同种茶叶中的溶出率并不相同，锌离子溶出率大于铁离子的溶出率。关键词：火焰原子吸收光谱法，微波消解法，茶叶，锌，铁，溶出率DeterminationofZnandFeinbrickteaandscentedteabyatomicabsorptionspectrometryAbstract：Thestudyaimedtounderstandthecontentofzincandironinbrickteaandjasmineteaandtheelementschangeintea.Brickteaandjasmineteaweredigestedbymicrowavedigestionmethod,zincandironcontentinteaweredeterminedbyflameatomicabsorptionspectrometry.Atthesametime,zincandironcontentchangesalongwiththetimechangeintwoteawerediscussed.Theresultsshowedthatthesameelementindifferentkindsofteahadacertaindifferenceinthecontent,andthecontentofzincinbrickteawas120.93mg/kg,thecontentofironinbrickteawas849.50mg/kg,thecontentofzincinjasmineteawas66.13mg/kg,thecontentofironinjasmineteawas236.33mg/kg.Theexperimentmethodofzincrecoveryratewas87.00%~116.83%,therecoveryrateofironwas95.13%~118.17%,recoveryraterangedbetween80%~120%,relativestandarddeviationwaslessthan5.1031%,thatshowedthemethodhadgoodaccuracy.Zincandironioninbrickteabiggestdissolutionratewere14.39%and2.49%,zincandironioninteabiggestdissolutionratewere40.83%and8.96%,whichexplainedthatdifferentkindsofelementsinthesameteadissolutionratewasnotthesame,andzinciondissolutionratewasgreaterthanthedissolutionrateofironion.KeyWords:Flameatomicabsorptionspectrometry,Microwavedigestion,Tea,Zinc,Iron,Dissolutionrate目录文献综述………………………………………………………………………………11前言………………………………………………………………………………….32材料与方法………………………………………………………………………….42.1实验仪器..…………………………………………………………………....42.2实验试剂..……………………………………………………………………42.3仪器工作条件...……………………………………………………………...42.4实验方法……………………………………………………………………42.4.1样品前处理……………………………………………………………….42.4.2标准储备溶液的配制…………………………………………………….42.4.3方法检出限实验……………………………………………………….....52.4.4标准曲线的绘制…………………………………………………………...52.4.5精密度实验………………………………………………………………...52.4.6样品中元素总含量的测定………………………………………………...62.4.7样品加标回收率的测定…………………………………………………...62.4.8不同时间茶水中元素溶出率的测定……………………………………..63实验结果…………………………………………………………………………….73.1检出限……………………………………………………………………....73.2标准曲线的绘制…………………………………………………………....83.3精密度………………………………………………………………………93.4样品元素总含量..………………………………………………………...