罗丹明B光谱探针测定祛斑霜中微量汞

Determination of micro constituent mercury in freckle cream using Rhodamine B as spectroscopic probe

罗丹明B为光谱探针,研究了在三羟甲基氨基甲烷-HCl缓冲溶液(pH=6.5)中,十二烷基苯磺酸钠(SDBS)存在下,分光光度法测定祛斑霜中微量汞离子,得出了测定的优化条件。实验表明,室温下罗丹明B-SDBS-Hg2+形成水溶性三元复合物,最大吸收波长为554nm,表观摩尔吸光系数ε=2.43×105L.mol-1.cm-1。Hg2+质量浓度在0～3.00μg/mL范围内服从朗伯-比尔定律。检出限为0.021μg/mL,加标回收率为98.5%～100.3%,RSD为1.06%～1.11%。

Method for spectrophotometric determination developed with Rhodamine B as spectroscopic probe in of micro constituent mercury in freckle cream was a buffer solution of trihydroxymethyl amino methane hydrochlofide salt （pH=6.5） and in the presence of an anionic surfactant sodium dodecylbenzene sulfonate （SDBS）. Conditions for carrying out the determination were identified. Results showed that, under room temperature a ternary complex substance Rhodamine B - SDBS - Hg^2＋ is formed with maximum absorbanee at wavelength of 554 nm. For Hg^2＋ content in the scope of 0-3.00μg/mL, it follows Lambert - Beer Law. Apparent molar absorption coefficient is 2.43×10^5L·mol^-1·cm^-1. Detection limit achieves 0.021μg/mL. Recovery is in the scope of 98.5%—100.3%. RSD is in the scope of 1.06%—1.11%.