title: [Study on microwave digestion of gypsum for the determination of multielement by ICP-OES and ICP-MS].
abstract: Three acids (HNO3, HNO3/HF and HNO3 /HF+ H3BO3) were used to decompose gypsum with microwave digestion system. The contents of 10 mineral elements (Al, Ca, Mg, Fe, K, Na, S, Ti, Si and Sr) in gypsum were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) while 6 heavy metals (V, Cr, Mn, Zn, Se and Ce) were determined by inductively coupled plasma-mass spectrometry (ICP-MS). GBW03109a, GBW03110 and FGD-2 were used as gypsum standard reference materials. The results showed that two-step microwave digestion with HNO3/HF at 210 degrees C and then adding H3BO3 for the removal of HF and fluorides completely decomposed the gypsums, while this method achieved good recoveries for all elements in the three gypsum standard reference materials. The recovery was from 88% to 112% and the RSD of tests was below 3%. The method was applied to the elemental analysis for flue gas desulfurization gypsums from three coal-fired power plants.
authors.affiliation: Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing, China. kingbill@163.com
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Song
authors.forename: Rui-ming
authors.initials: RM
authors.lastname: Yang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yao
authors.forename: Chang-he
authors.initials: CH
authors.lastname: Chen