微波消解-分光光度法测定化妆品中铅含量的研究

Study on Microwave Digestion-spectrophotometric Determination of Pb Content in Cosmetic Samples

用微波消解法批量处理样品,并用2-(2-喹啉偶氮)-4,5-二羟基苯酚溶液(0.05%)作为显色剂,pH为7的HAcNaAc溶液作为缓冲液,2 mol浓度为1%的吐温80作为表面活性剂,3 m L的2-(2-喹啉偶氮)-4,5-二羟基苯酚溶液(0.05%)在室温下可与Pb2+发生显色反应。λ_(max)为550 nm,ε为2.5×10~4L/mol·cm,Pb(Ⅱ)的质量浓度范围在050μg/25 m L,是符合比尔定律的,该方法可用于测定化妆品样品中的铅含量,能取得较为满意的结果。

Using 2- （2-quinolyl azo ） - 4,5 - dihydroxy phenol （ 0.05 % ） as ehromogenie agent, large quantities of samples were treated by microwave digestion, taking HAe-NaAc in pH 7 as buffer solution, 2 mol of 1% Twain＇s 80 as surface active agent, color reaction of 3 mL 2- （2-quinolylazo） -4,5-dihydroxy phenol solution （0. 05% ） with Pb^2＋at room temperature was investigated. Lead（ Ⅱ ） was in the concentration range of 0 -50 μg/25 mL, reached the maximum absorption at 550 nm with molar absorptivity of 2.5 × 10^4 L/mol.em, met the Beer＇s law. This method can achieve satisfactory results for the determination of trace Pb（ Ⅱ ） content in cosmetics.