火焰原子吸收分光光度法測定茶葉中八種金屬元素含量

發布時間:2019-09-02 來源: 歷史回眸 點擊:

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  摘要:建立了利用火焰原子吸收分光光度法測定3種立頓茶包茶(Camellia sinensis L.)葉中的鈣、鉀、鈉、鎂、鐵、銅、鋅、錳等8種金屬元素的含量的方法。利用濕法消化(濃硝酸∶高氯酸=4∶1,V/V)處理樣品,通過標準曲線法得到各元素含量,并對樣品的回收率進行了測定。在選定的試驗條件下,各元素在相應的濃度區間內呈良好的線性關系,相關系數為0.995 9~0.999 6,檢測限為0.002~0.008 μg/mL,回收率為92.0%~114.8%,相對標準偏差為0.52%~3.33%。結果表明,8種元素在3種茶葉中的含量各不相同,3種茶葉中鈉元素和鎂元素的含量較接近,綠茶中鉀元素及錳元素含量較高,紅茶中鈣元素、銅元素、鐵元素及鋅元素的含量較高。該方法測定茶葉中的各種元素操作簡便,干擾較少,靈敏度高。
  關鍵詞:原子吸收分光光度法;茶(Camellia sinensis L.)葉;金屬元素;濕法消化
  中圖分類號:O657.31 文獻標識碼:A 文章編號:0439-8114(2016)22-5931-03
  DOI:10.14088/j.cnki.issn0439-8114.2016.22.050
  Determination of Eight Kinds of Metal Elements in Teas
  by Flame Atom Absorption Spectrometry
  DU Juan,XIONG Jian-hua,WANG Xiong,LU Tao,WU Guo-qiang,LUO Qiu-shui
  (College of Food Science and Engineering,Jiangxi Agricultural University,Nanchang/Key Lab for Agro-products Processing & Quality Control of Nanchang,Nanchang 330045,China)
  Abstract:Determination of Ca,K,Na,Mg,Fe,Cu,Zn,Mn in three kinds of Lipton teas by flame atomic absorption spectrophotometry were established. Samples were with treated wet digestion[V(HNO3)∶V(HClO4)=4∶1],and determined by standard curve method. The recoveries were determined as well. Under the selected conditions,all eight kinds of metal elements showed good linearity in their own corresponding concentration ranges, with the correlation coefficients between 0.995 9~0.999 6,the detection limit 0.002~0.008 μg/mL,the recovery rates 92.0%~114.8%,the relative standard deviations 0.52%~3.33%. The results showed that concentrations of eight kinds of metal elements in three kinds of teas were different. Concentrations of Na and Mg were close to each other in these three kinds of teas; concentrations of K and Mn were highest in the green tea,however concentrations of Ca,Cu,Fe,and Zn were highest in the black tea. This method has the advantage of simple operation, less interference and high accuracy.
  Key words:Atomic absorption spectrophotometry(AAS); tea(Camellia sinensis L.); metal elements; wet digestion
  茶(Camellia sinensis L.)葉中含有各種人體所需的常量元素和微量元素,各種元素常以有機態存在,便于人體吸收[1],具有一定的保健功能。根據不同的制作工藝可將茶葉分為綠茶、紅茶、黑茶、烏龍茶、花茶等,其中綠茶及紅茶是人們最常飲用的茶。近年來,具有花的清香的各類花茶也越來越受到大眾,尤其是白領女性的青睞。測定茶葉中各金屬元素的含量對于研究茶葉的保健作用具有一定的意義。本研究以立頓綠茶、紅茶及茉莉花茶3種茶包茶葉為研究對象,采用濕法消解,以混合酸處理樣品,利用火焰原子吸收分光光度法分別測定了3種茶葉樣品中鈣、鉀、鈉、鎂4種常量元素和鐵、銅、鋅、錳4種微量元素的含量,建立了茶葉中這8種元素含量的測定方法,并對該方法的準確度和精密度進行了考察。
  1 材料與方法
  1.1 材料與儀器
  立頓綠茶、紅茶、茉莉花茶樣品,均購自聯合麗華有限公司。
  各元素標準儲備液,含量均為1 000 g/mL,購自國家鋼鐵材料測試中心。
  試驗中所用試劑均為國產分析純,所用水均為超純水,所用玻璃儀器均用10%硝酸浸泡24 h以上,用超純水洗凈,晾干后備用。

相關熱詞搜索:金屬元素 光度 分光 原子 八種

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