饵料加标研究二甲苯麝香在鱼体内的蓄积和清除能力

二甲苯麝香(musk xylene,MX)是一种人造麝香,具有强烈的麝香气,可用作化妆品香精和皂用香精等的定香剂。由于其持续不断地输入环境,它们在水、土壤、大气中的浓度逐渐升高,并且在动物和人体组织中产生了蓄积,其蓄积效应相当于有机氯农药(organochlorine pesticides,OCPs)等持久性有机污染物,因而研究MX在鱼体内的蓄积特征是十分必要的。本文用含浓度为50 mg·kg-1和100 mg·kg-1的MX的饵料投喂斑马鱼(Danio rerio)和稀有鮈鲫(Gobiocypris rarus)14 d,继而进入为期28 d的清除实验。通过快速溶剂萃取(accelerated solvent extraction,ASE)、凝胶渗透色谱(gel permeation chromatography,GPC)、气相色谱-质谱联用法(gas chromatography-mass spectrometry,GC-MS)测定斑马鱼和稀有鮈鲫体内MX的浓度,继而评估鱼对MX的清除能力。结果表明,饵料中MX浓度越高,鱼体内MX的蓄积水平越高,100 mg·kg-1浓度组的蓄积水平为50 mg·kg-1浓度组的蓄积水平的2~3倍。在整个试验阶段的不同时间点分析鱼的体重和脂肪与鱼体内MX浓度的关系,数据显示,MX在鱼体内的蓄积水平与鱼的体重存在正线性关系,而与鱼体内脂肪含量的关系还有待进一步研究。经28 d的清除,鱼体内的MX残留量接近于零,说明斑马鱼和稀有鮈鲫对MX的清除能力较强。

Analysis of the Dietary Exposure Bioaccumulation and Depuration of MX-Spiked Feed in Fish

Musk xylene (MX) is a synthetic musk fragrance ingredient with strong odor characteristics used as fixative principally in cosmetics and soaps. Because of its continuous input to environment, the concentrations of MX was increasing in water, soil and air, and concentrated in animals and human tissues. Its accumulative effect was equivalent to that of persistent organic pollutants such as organo-chlorine pesticides (OCPs).It was necessary to study the bioaccumulation of MX in fishes. Zebrafish (Danio rerio) and Rare Minnow (Gobiocypris rarus) were fed with MX-containing chow (0, 50 and 100 mg MX/kg fish feed) for 14 days followed by 28 days of clean food. The concentrations of MX in Zebrafish and Rare Minnow were measured by accelerated solvent extraction (ASE), gel permeation chromatography (GPC) and gas chromatography-mass spectrometry (GC-MS), and then the depuration ability of fish to MX was evaluated. The more MX content in diets, the higher MX concentration was found in fishes, e.g., the MX in fishes of 100 mg·kg^-1 was two or three times as high as that of 50 mg·kg^-1. A positive linear relationship was observed between the MX concentration in fishes and body weight of fishes, however, the body fat content was not related to the MX concentration in fishes. After depuration for 28 days, the levels of MX in fishes were close to zero, implying that Zebrafish and Rare Minnow have a strong ability to depurate MX.