在自然界中鉻主要以鉻鐵礦[Fe(CrO2)2]的型式存在著。工業上則是以元素鉻、三氧化鉻(CrO3) 、三氧化二鉻(Cr2O3)、鉻酸(H2CrO4)以及鉻酸鹽或重鉻酸鹽最被廣泛使用。鉻的用途隨著時代與工業的發展以及人類生活水準的提高而相對增加。而這也使得鉻對環境污染的可能性隨著其用途的增加而增加,而有了越來越嚴重的情況。 本研究主要是經由運用離子層析法結合化學放光法,同時進行三價鉻以及六價鉻在水溶液中的檢測分析。研究中運用 CS5A 離子層析管柱先將三價鉻以及六價鉻進行分離,放光試劑會藉由三價鉻的催化反應而放光,但六價鉻在此反應中並不具有催化能力,所以必須先將六價鉻還原成三價鉻才能使其放光而偵測到。本研究也將沖提液的鹽類種類做改變,改成以 KBr 取代 KCl 作為研究中所使用之沖提液鹽類,並關注其中的改變以及放光效益是否更佳。 三價鉻以及六價鉻的方法偵測極限分別為 0.08 μg/L及 0.22 μg/L。三價鉻的檢量線製備結果在 0.0 – 5.0 ppb 顯示有良好的線性範圍, R2 值為0.9966;而六價鉻的檢量線製備結果則顯示在 0.0 – 25.0 ppb有良好的線性範圍, R2 值為 0.9998。 在進行干擾測試時,添加三價鉻以及六價鉻於 Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)、Co(Ⅱ)、Ca(Ⅱ) 及 Pb(Ⅱ) 之混合金屬溶液中,發現樣品中六價鉻的訊號會被混合金屬之訊號覆蓋,而三價鉻的訊號以及回收率則會因混合金屬濃度上升而降低。
Chromium exists in the nature principally as chromite (Fe(CrO2)2) . Industries consume chromium in various forms including chromium metal , chromium (III) oxide (Cr2O3) , chromium (VI) oxide (CrO3) , chromic acid (H2CrO4) , and various chromates (CrO42-) . Most of the chromium usage is by the steel industry for steel production and , accompanying the increasing need for steel , chromium pollution has dramatically over the years . Chromium exists in aqueous samples either as the trivalent (Cr3+) or hexavalent ( CrO42- or Cr2O72- ) form . Trivalent chromium is a natural essential element in our body , while the hexavalent form is considered toxic to humans . The goals of this research is to develop a fast and convenient method and improvement the method for chromium speciation in aqueous samples by simultaneous analysis of trivalent and hexavalent chromium ions with Ion chromatography-Chemiluminescence Detection (IC-CLD) . The IC-CLD in this research use of an IC mixbed CS5A column for separation of Cr(III) and Cr(VI) ions before reducing the Cr(VI) ions to Cr(III) ions after the column separation . The reason for reducing the hexavalent form to trivalent form is because hexavalent chromium does not possess catalytic activity for luminescing agent used in this research . The CLD system used in this research is luminol/hydrogen peroxide . At the absence of a catalyst , the luminol/hydrogen peroxide system undergoes a luminol oxidation reaction ; the presence of a catalyst accelerates the oxidation reaction , and thus more light is given off . The light given off is measured as a linear function of catalyst (Cr(III)) concentration and this forms the basis of the CLD detection method . The method detection limit (MDL) for trivalent and hexavalent chromium was found to be 0.08 μg/L and 0.22 μg/L .
為了持續優化網站功能與使用者體驗,本網站將Cookies分析技術用於網站營運、分析和個人化服務之目的。
若您繼續瀏覽本網站,即表示您同意本網站使用Cookies。