【摘要】 对多种无机磷和有机磷化合物进行了实验 ,尝试了不少盐试剂 (本文称之为灰化助剂 ) ,研究它们在灰化法提取磷中的作用效果和机制。我们发现 ,许多无机磷和有机磷化合物加入MgSO4灼烧后残渣中的磷并不完全回收。而MgCl2 、Mg(Ac) 2 、CaCl2 等助剂 ,却都能使灼烧后的磷易于完全回收。我们认为 ,在利用目前已被广泛应用的MgSO4高温灰化法分析水体中的颗粒磷和总磷或有机体中的磷时 ,应当用MgCl2 取代MgSO4作为灰化助剂。而对于硫酸盐含量低的样品 ,CaCl2 同样是很有效的灰化助剂。尽管Mg(NO3 ) 2 也是高效的灰化辅助剂 ,但其应用存在危险性及较多的手工操作等缺陷 ,且还存在MgSO4的盐效应问题 ,这限制了其广泛应用。本研究认为 ,如果沉积物中加入MgCl2 后灰化 ,用 0 .2mol LHCl于 80℃浸提残渣 0 .5h足以达到分析目的更多还原

【Abstract】 Phosphorus recoveries from selected inorganic and organic P-containing compounds after ignition with auxiliaries, such as MgSO 4, Mg(NO 3) 2, MgCl 2, Mg(Ac) 2 and CaCl 2 were studied. It was found that the phosphorus could not be completely recovered when most P-containing compounds were ignited with MgSO 4 at temperature not higher than 500℃ if the baked residue was extracted with 0.2 mol/L HCl for 30 min at 80℃ or at room temperature. In contrast, MgCl 2, Mg(Ac) 2 and CaCl 2, as well as Mg(NO 3) 2, could all yield complete P recoveries. We suggest that MgCl 2 rather than MgSO 4, which is usually used, should be utilized as ashing auxiliary agent in the P extraction by ignition method. Although Mg(NO 3) 2 is a highly effective auxiliary agent, yet interference from MgSO 4, danger of explosion, toxicity of nitrogen dioxide and more manipulation steps may limit its widespread utilization. It is suggested that if sediment is ignited with MgCl 2, the extraction of residue with 0.2 mol/L HCl for 30 min at 80℃ could give good result.更多还原