【摘要】 以铬天青Ｓ和邻菲啉作混合显色剂，不需预分离，可用双波长分光光度法同时测定氮化硅消解液中的铁和铝。［Ｆｅ（ｐｈｅｎ）３］２＋和Ａｌ（ＣＡＳ）３的吸收光谱有部分重叠，通过读取在两个等吸收波长处的吸光度可消除吸收干扰，测铁所选的波长对为５０４／５９５ｎｍ，测铝的波长为［Ｆｅ（ｐｈｅｎ）３］２＋不产生吸收的５８１ｎｍ．测量在ｐＨ＝６．０的ＨＡＣ－ＮａＡＣ缓冲溶液中进行。测铁的线性范围为０～４ｍｇ／Ｌ，测定值的相对标准偏差为０．８１％，平均回收率为９９．７％；测铝的线性范围为１．４ｍｇ／Ｌ，测定值的相对标准偏差为２．３１％，平均回收率为１０１．１％。更多还原

【Abstract】 Iron and aluminium in the digestion solution of silicon nitride are determined simultaneously by double wavelength spectrophotometry with the mixture of chrome azurol S (CAS) and phenanthroline (Phen ) as the double chromogenic reagents, separation of the two elements from components is not needed in the determination. The absorptive spectrums of [Fe(phen)3]2+ and Al(CAS)3 overlap to each other partically. The absorption interference can be eliminated by taking the reading of absorbance at isoabsorptive wavelength, the wavelength pair selected for the iron determination is 504/595 nm, the wavelength for the aluminium deter mination is 581 nm at which the complex with Fe2+ has no absorption. The determination is made in HAc-NaAc buffer medium at PH 6. 0. The linear range of the iron determination is 0-4 mg/L, the relative standard deviation is 0. 8% and the average recovery is 99. 7 %. The linear range of the aluminium determination is 1. 4 mg/L, the relative standard deviation is 2. 31 %,and the average recovery is 101. 1 %.更多还原