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铝的测定——铬天青S分光光度法 一、方法要点: 试样经硝酸溶解后,高氯酸冒烟,用Zn-EDTA作掩蔽剂,以六次甲基四胺作缓冲液在pH 5.5±0.4和铬天青S生成紫红色络合物,以此测定吸光度。 二、测定范围:0.02～0.1％ 三、所需试剂: 1.硝酸:(1:3) 2.高氯酸:70％ 3.Zn-EDTA;(0.1M:0.1M)称取氧化锌8.1克,加入盐酸20毫升溶解,另取EDTA37.25克于1000毫升烧杯中,加入约800毫升水,加热溶解后,冷却,加入氨水约18毫升左右,然后将氯化锌溶液倒入搅匀,调节pH约4～5,以水稀至1000毫升,摇匀。 4.六次甲基四胺;30％ 5.氟化铵;1％
Determination of aluminum - Chromazurol S spectrophotometry First, the method points: sample dissolved in nitric acid, perchloric acid smoke, with Zn-EDTA as a masking agent, hexamethylenetetramine as a buffer solution at pH 5.5 ± 0.4 and chromazurol S generated purple complexes, absorbance was measured. Second, the determination of the range: 0.02 to 0.1% Third, the required reagents: 1. Nitric acid: (1: 3) 2. Perchloric acid: 70% 3.Zn- EDTA; (0.1M: 0.1M) Weigh zinc oxide 8.1 G, dissolved in 20 ml of hydrochloric acid, another EDTA37.25 g in 1000 ml beaker, add about 800 ml of water, dissolved by heating, cooling, adding about 18 ml of ammonia, and then the zinc chloride solution into the mix, Adjust pH about 4 ~ 5, diluted with water to 1000 ml, shake. 4. Hexamethylenetetramine; 30% 5. Ammonium fluoride; 1%