【摘要】 本文提出硅石消解新技术——微波消解法。于聚氯乙烯消解罐中加硝酸、氢氟酸、高氯酸,程序加压升温分解硅石。微波消解法与冰浴法、加热消解法相比,可避免待测元素在分解过程带来的损失,且分解完全,酸用量少,操作简单、可靠。硅石经微波消解后采用火焰原子吸收光谱法检测铁、锰、镁、钙,铁、锰、镁、钙的回收率分别为97.3%~99.0%、104.4%~106.5%、95.7%~98.0%、103.1%~106.6%,与国家标准方法分析结果比较,相对误差均小于5%。更多还原

【Abstract】 Compared with mixed acid digestion using ice bath or heating,microwave digestion as a new digestion technique was proposed.The digested reagents,including 4.00 mL nitric acid,1.00 mL hydrofluoric acid and 0.50 mL perchloric acid,were added to digest 0.2 g silica;then the microwave digestion system was adjusted as follows: 10 atm for 5 min,15 atm for 5 min,and 20 atm for 5 min.This microwave digestion has advantages of avoiding the lost of trace element,decomposing completely,less dosage of acid and easy operation.The contents of iron,manganese,magnesium and calcium in silica were determined by flame atomic absorption spectrometry.Recoveries were in the range of 97.3%~99.0% for iron,104.4%~106.5% for manganese,95.7%~98.0% for magnesium and 103.1%~106.6% for calcium,respectively.The analytical results obtained by the proposed method were compared with those obtained by the national stoundard method,and the relative deviation was found to be under 5%.更多还原