燃煤電廠煤中砷(As)的形態(tài)在燃燒過(guò)程中不可避免地會(huì)發(fā)生轉(zhuǎn)化。煤及其副產(chǎn)物中砷的形態(tài)與人體健康和環(huán)境安全密切相關(guān),亟待鑒別。然而目前針對(duì)煤燃燒相關(guān)產(chǎn)物中砷形態(tài)的前處理手段和分析方法尚缺乏。本研究采用高效液相色譜-氫化物發(fā)生-原子熒光光譜法(HPLC-HG-AFS)成功測(cè)定了電廠煤、粉煤灰和石膏中砷的形態(tài),優(yōu)化了儀器參數(shù)、提取試劑和前處理方法(超聲和微波輔助)。優(yōu)化后,無(wú)機(jī)砷的分離時(shí)間縮短至7 min,As(III)和As(V)的檢出限分別為1.8 ng/g和4.6 ng/g。砷形態(tài)的高效提取劑為1.0 mol/L磷酸和0.1 mol/L抗壞血酸的混合溶液。微波輔助(2000 W、80℃、40 min)和超聲輔助(40 kHz、20℃、40 min)分別是煤/粉煤灰和石膏樣品中砷形態(tài)的最佳提取方法。在微波和超聲波輔助提取條件下,As(III)/As(V)的回收率分別為95.8%/104.5%和90.6%/89.7%。樣品分析結(jié)果表明,煤中砷主要以As(V)形式存在,As(III)所占比例很小,而在粉煤灰和石膏中只觀察到As(V)。該研究揭示了As(III)向As(V)的轉(zhuǎn)化是氣態(tài)砷捕獲的...

【文章頁(yè)數(shù)】：8 頁(yè)

【文章目錄】：
1 Materials and methods
    1.1 Samples preparation
    1.2 Reagents
    1.3 As extraction and determination
        1.3.1 Total As analysis
        1.3.2 As speciation analysis
2 Results and discussion
    2.1 As chromatographic separation
    2.2 As speciation extraction
        2.2.1 Optimization of extraction reagent
        2.2.2 Effect of different extraction methods
        2.2.3 As stability during extraction
    2.3 Method validation
    2.4 Arsenic speciation in coal and its by-products
        2.4.1 As speciation in coal
        2.4.2 As speciation in fly ash
        2.4.3 As speciation in gypsum
    2.5 As species transformation
3 Conclusions



本文編號(hào)：4046384