石墨炉原子吸收法测定大鼠饮用富硒绿茶后硒元素在大鼠组织中的含量

Determination of Selenium in Rat Tissues after Oral Administration of Selenium-enriched Green Tea by Graphite Furnace Atomic Absorption Spectrometry

通过建立测定大鼠血浆、心脏、肝脏、睾丸、胰腺、肺、指甲、脑、肾脏和肌肉组织中硒含量的石墨炉原子吸收法,测定大鼠饮用富硒绿茶后硒元素在各组织中的含量和分布情况。将大鼠随机分为富硒绿茶组(10 g/kg)、非富硒绿茶组(10 g/kg)和空白组,每组6只,连续灌胃30 d,每天一次。采用湿法消化法处理大鼠组织样品,以石墨炉原子吸收法测定其硒的含量。采用标准加入法制备工作曲线,经方法学验证,各组织硒的含量在10~100 ng/mL范围内线性关系良好(r≥0.99136),批间和批内精密度小于12.2%,平均准确度89.5%~106.9%之间,平均回收率86.1%~95.1%之间;组织分布研究表明富硒绿茶组与空白组相比,其心脏、睾丸、肺、肝脏、肾脏和胰腺的硒含量有明显增加;与非富硒绿茶组比,其胰腺的硒含量有明显增加。本研究通过优化组织样品预处理过程和分别为各组织制备工作曲线所建立的石墨炉原子吸收法准确度好,重复性高,可以适用于测定大鼠饮用富硒绿茶后各组织中硒的含量,大鼠饮用富硒绿茶后能够吸收其硒元素,各组织中的硒含量在安全范围之内。

A method for the determination of selenium（Se） concentrations in rat plasma, heart, liver, testicle, pancreas, lung, nail, brain, kidney, and muscle by graphite furnace atomic absorption spectrometry（GFAAS） was developed and validated. The content and distribution of selenium in rat tissues after oral administration of selenium-enriched green tea were then determined. In this assay, male rats were randomly divided into selenium-enriched group, non-selenium-enriched group, and blank group（n=6）, which were given 10 g/kg selenium-enriched green tea, non-selenium-enriched green tea, and 10 mL/kg ultra-pure water once per day for 30 d, respectively. The rat tissues were wet-digested and the selenium contents were determined by GFAAS. The standard curve was constructed using the standard addition method, and the result of method validation showed that the developed GFAAS method exhibited a good linearity over the concentration range of 10~100 ng/mL（r≥0.99136）. The intra-batch and inter-batch precision were all within 12.2% at three concentration levels. The mean accuracies and recoveries were 89.5%~106.9% and 86.1%~95.1%, respectively. The results of selenium distribution in tissues showed that the selenium contents in rat heart, testicle, lung, liver, kidney, and pancreas in the selenium-enriched green tea-treated group increased significantly compared to those of the blank group, and the selenium level in the pancreas increased significantly compared with that of the non-selenium-enriched green tea-treated group. In conclusion, the developed GFAAS method of optimizing sample preparation and constructing the standard curve for each tissue is accurate and reproducible, and is suitable for the determination of selenium content in rat tissues after administration of selenium-enriched green tea. The selenium in the enriched green tea could be absorbed by rats, and the selenium contents in all rat tissues were lower than the toxic level.