摘要
在稀硫酸介质中,罗丹明B于特定激发波长下可发射较强的荧光,少量过硫酸钾可氧化罗丹明B使体系的荧光强度下降,钐对过硫酸钾氧化罗丹明B的反应有阻抑作用。在拟定实验条件下,荧光阻抑值与钐浓度呈线性关系,据此建立了一种测定钐的荧光光度法。讨论了酸度、氧化剂用量、罗丹明B用量、反应时间和反应温度及共存离子等对体系的影响,确定了最佳实验条件。测定了表观反应速率常数和表观活化能。在拟定实验条件下,方法的线性范围为0.040～0.18μg/mL,检出限为2.67×10-4μg/mL。方法用于银合金中钐的测定,测定值与DBC-偶氮氯膦光度法一致,相对标准偏差(n=5)小于2.5%。
In dilute sulfuric acid medium,rhodamine B could emit strong fluorescence at specific excitation wavelengths,and the fluorescence intensity was decreased after rhodamine B was oxidized by a small amount of potassium persulfate.Samarium？ has inhibitory effect on the oxidation reaction of potassium persulfate with rhodamine B.In the selected experimental conditions,it has a linear relationship between the inhibitory fluorescent intensity and samarium concentration,thus a fluorometry for determination of samarium was established.The influence factors were discussed,such as acidity,oxidant dosage,rhodamine B dosage,reaction time,reaction temperature and coexisting ions.The optimum reaction conditions,as well as the apparent reaction rate constant and the apparent activation energy were obtained.The linear range was 0.040-0.18μg/mL,and the detection limit was 2.67 × 10^-4μg/mL.The method has been applied to the determination of samarium in silver alloy.The results were in accordance with those obtained by chlorophosphonazo spectrophotometry,and the relative standard deviation（n=7）was less than 2.5%.
出处
《冶金分析》
CAS
CSCD
北大核心
2013年第6期72-75,共4页
Metallurgical Analysis
关键词
荧光光度法
钐
过硫酸钾
罗丹明B
fluorometry
samarium
potassium persulfate
rhodamine B
