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原子吸收分光光度法测定砷,包括火焰法和无焰法.已有不少文献介绍。火焰法测定砷,有空气-乙炔火焰、氩气-氢气火焰、空气-氢气火焰、氧化亚氮-乙炔火焰等,不足之处是灵敏度低。在测定低含量砷时,就必须采用无焰法——石墨炉法和氢化法.石墨炉法灵敏度可达10~(-11)克,但基体干扰较大。近年来,氢化法被广泛采用,即先将砷转化为砷化氢气体,再用原子吸收分光光度计测定。使用的还原剂有锌、氯化亚锡和硼氢化钠等.捕集砷化氢的方式亦有多种:有捕集在一气袋内,再引入火焰中的;有将捕集器放入液氮中冷却,再转化为气体引入火焰中的;有将砷化氢溶解于溶液中,然后进行喷雾的。亦有一些方法不经捕集,将砷化氢气体直接引入氩气-氢气火焰,或引入石英管原子化器.石英
Determination of arsenic by atomic absorption spectrophotometry, including flame method and flameless method. Determination of arsenic flame, air - acetylene flame, argon - hydrogen flame, air - hydrogen flame, nitrous oxide - acetylene flame, the downside is the low sensitivity. In the determination of low levels of arsenic, it is necessary to use the flameless method - graphite furnace and hydrogenation method. Graphite furnace sensitivity up to 10 ~ (-11) grams, but the substrate interference. In recent years, the hydrogenation method is widely used, that is, arsenic is first converted to arsine gas, followed by atomic absorption spectrophotometer. The reductants used are zinc, stannous chloride and sodium borohydride, etc. There are also many ways to capture arsine: trapped in a gas bag and then introduced into the flame; Liquid nitrogen cooling, and then into the gas into the flame; have arsine dissolved in solution, and then spray. There are also some methods without capture, the arsine gas directly into the argon - hydrogen flame, or the introduction of quartz tube atomizer. Quartz