石墨炉原子吸收光谱法测定镉中毒小鼠尸体中大头金蝇体内的镉和金属硫蛋白

Determination of Cadmium and Metallothionein in Chrysomya megacephala from Mouse Body with Graphite Furnace Atomic Absorption Spectrometer

目的：研究尸食性蝇类大头金蝇体内的镉（Cd）浓度能否反映所寄生尸体生前的Cd投毒量。方法：大头金蝇初产卵接入Cd中毒小鼠尸体,分别于产卵后3 d（幼虫）、7 d（幼虫）、9 d（蛹）收集幼虫（蛹）样本,用微酸量消化处理测Cd,用Cd-血红蛋白饱和法处理测金属硫蛋白（MT）。塞曼效应校正背景,石墨炉原子吸收法进行测定。结果：方法检出限分别为：Cd0.024μg/L和MT 0.027μg/L。回收率实验分别为Cd 94.3%~105.0%,MT 90.2%~108.0%。大头金蝇幼虫随着生长时间增加Cd蓄积也增加,但蛹期Cd浓度减少,MT表达也表现类似规律,各个生长期的Cd浓度与投毒量呈线性相关。结论：检测昆虫体内的Cd,可用于判断尸体生前摄入的Cd是否达到致死量。

Objective： To investigate whether cadmium （Cd）content in Chrysomya megacephala could reflect the amount of CA which was taken in the mouse body. Method： Spawns of Chrysomya megacephala were put in the bodies of mouse which were poisoned by Cd. Larva/chrysalides were collected at day 3, 7, and 9, which were subjected to microdigesting with acid and determined the concentration of CA. Cd-hemoglobin saturation method was applied to determine the level of metaUothionein（MT）. Graphite furnace atomic absorption spectrometer（GFAAS）was used in this study, and the background correction was based on the Zeeman effect. Results： The detection limit of this method was ： CA, 0.024 ug/L, with recovery of 94.3%-105.0%, and MT, 0.027 ug/L, with recovery of 90.2%-108.0%. The accumulation of CA was observed with the growth of larva. Cd concentration decreased in chrysalides. The change of kiT was similar to that of Cd. Linear relationship was found between the amount of Cd poisoned and the level of Cd in larva at different period of growth. Conclusion： Cd content in Chrysomya megacephala can reflect the amount of Cd that can cause death.