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试样用硝酸溶解,加硝酸锶和硫酸生成SrSO_4+PbSO_4混晶共沉淀,过滤,与铜、镍、镉、锌、铁、锰、锑、铋等元素分离。沉淀加硝酸溶解,沉淀中所夹杂的干扰离子,在pH5.5乙酸盐介质中,用硫代硫酸钠,氟化铵、盐酸羟胺、抗坏血酸、邻菲啰啉联合掩蔽,加BPR、OP、CTMAB与铅生成紫色的络合物,在620～630nm处有最大吸收。铅10～140μg/25毫升符合比耳定律,测定范围0.002～0.23%。再现性和准确度满足日常分析要求。一试剂乙酸盐缓冲溶液:pH5.5,称NaAc·3H_2O 125克加水溶解,加冰乙酸6.0毫升于1升量瓶中稀至刻
The samples were dissolved with nitric acid, SrSO_4 + PbSO_4 mixed crystals were formed by adding strontium nitrate and sulfuric acid, and were filtered and separated from copper, nickel, cadmium, zinc, iron, manganese, antimony and bismuth. Precipitation plus nitric acid dissolved precipitation precipitation interference ions, in pH5.5 acetate medium, with sodium thiosulfate, ammonium fluoride, hydroxylamine hydrochloride, ascorbic acid, phenanthroline joint masking, plus BPR, OP, CTMAB forms a purple complex with lead and has a maximum absorption at 620-630 nm. Lead 10 ~ 140μg / 25 ml Beer’s law in line with the determination of 0.002 ~ 0.23%. Reproducibility and accuracy meet daily analytical requirements. A reagent acetate buffer solution: pH5.5, said NaAc · 3H_2O 125 g dissolved in water, add glacial acetic acid 6.0 ml in 1 liter flask dilute to carve