Determination of Halogens in Coal after Digestion Using the Microwave-Induced Combustion Technique
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- 作者：É ; rico M. M. Flores ; Má ; rcia F. Mesko ; Diogo P. Moraes ; Juliana S. F. Pereira ; Paola A. Mello ; Juliano S. Barin ; Gü ; nter Knapp
- 刊名：Analytical Chemistry
- 出版年：2008
- 出版时间：March 15, 2008
- 年：2008
- 卷：80
- 期：6
- 页码：1865 - 1870
- 全文大小：176K
- 年卷期：v.80,no.6(March 15, 2008)
- ISSN：1520-6882
文摘
The microwave-induced combustion (MIC) technique wasapplied for coal digestion and further determination ofbromide, chloride, fluoride, and iodide by ion chromatography (IC). Samples (up to 500 mg) were combustedat 2 MPa of oxygen. Combustion was complete in less than50 s, and analytes were absorbed in water or (NH4)2CO3solution. A reflux step was applied to improve analyteabsorption. Accuracy was evaluated for Br, Cl, and F usingcertified reference coal and spiked samples for I. For Br,Cl, and F, the agreement was between 96 and 103% using50 mmol L-1 (NH4)2CO3 as the absorbing solution and 5min of reflux. With the use of the same conditions, therecoveries for I were better than 97%. Br, Cl, and I werealso determined in MIC digests by inductively coupledplasma mass spectrometry, inductively coupled plasmaoptical emission spectrometry, and F was determined byan ion-selective electrode with agreement better than 95%to the values obtained using IC. Temperature duringcombustion was higher than 1350 
C, and the residualcarbon content was lower than 1%. With the use of theMIC technique, up to eight samples could be processedsimultaneously, and a single absorbing solution wassuitable for all analytes and determination techniques(limit of detection by IC was better than 3 
g g-1 for allhalogens).
C, and the residualcarbon content was lower than 1%. With the use of theMIC technique, up to eight samples could be processedsimultaneously, and a single absorbing solution wassuitable for all analytes and determination techniques(limit of detection by IC was better than 3 g g-1 for allhalogens).