矿物饲料添加剂生产过程中二恶英类生成机制研究

Dioxins in feed and feed additives would accumulate in cultured animals and tend to cause potential adverse effects in humans through the food chain. Mineral feed additives can provide essential metal trace elements for cultured animals. Several literatures have reported dioxin contaminations in mineral feed additives. However, studies on the formation mechanisms of dioxins during the production processes of mineral feed additives are scarce. In this project, the formation mechanisms and the impact factors of dioxins formed during the production processes of mineral feed additives will be studied. The target compounds include polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). Investigations on the raw materials and production processes of mineral feed additives will be conducted. The characteristics of dioxin congeners and the key factors that might effect dioxins generated during the production processes of mineral feed additives will be identified. The potential precursors of dioxins will be analyzed. Experiments will be conducted in the laboratory to investigate the factors that could potentially influence the generation of dioxins during the production processes of mineral feed additives. Dioxin formation characteristics and the formation mechanisms of dioxins under the experimental conditions will also be studied. This project would help reduce the risks of dioxin contaminations in mineral feed additives and provide scientific supports for feed quality safety.

饲料和饲料添加剂中的二恶英类能够在养殖动物体内蓄积，进而通过食物链对人体健康构成潜在的危害。矿物饲料添加剂能够为养殖动物提供必需的金属微量元素。虽然矿物饲料添加剂中二恶英类污染已见诸报道，但有关矿物饲料添加剂生产过程中二恶英类生成的研究尚待开展。本项目将对矿物饲料添加剂生产过程中二恶英类的生成机制及其关键影响因素进行探讨，目标化合物包括二恶英、多氯联苯和多氯萘。通过对矿物饲料添加剂原料以及矿物饲料添加剂生产工艺的调研，识别矿物饲料添加剂生产过程中二恶英类的生成特征和关键影响因素，明确二恶英类的重要前生体。结合矿物饲料添加剂的实际生产工艺，以实验室模拟的方式深入认识关键因素对二恶英类生成的影响，揭示矿物饲料添加剂生产过程中二恶英类的生成特征，提出矿物饲料添加剂生产过程中二恶英类生成的主导机制和关键影响因素，为降低矿物饲料添加剂中二恶英类污染风险，保障饲料质量安全提供科学支持。

动物性食品是一般人群二恶英类化合物暴露的最主要来源。饲料作为养殖动物的主要食物，饲料中的二恶英类化合物能够在动物体内蓄积，进而导致动物性产品中二恶英类化合物污染风险。含金属微量元素的饲料添加剂因使用工业原料，二恶英类化合物污染风险较高，但其污染形成机制尚不明确。本项目主要开展了矿物饲料添加剂生产过程中二恶英类化合物的生成机制研究，明确了不同种类矿物饲料添加剂原料中二恶英（PCDD/Fs）、多氯联苯（PCBs）和多氯萘（PCNs）的污染水平及其同类物分布特征，发现含铜元素的饲料添加剂具有较高的二恶英类化合物污染风险，且二恶英类化合物分布特征明显不同于其他样品；揭示了氯源、催化剂（铜）和温度是影响矿物饲料添加剂中二恶英类化合物生成的关键因素，发现从头合成可能是二恶英的主要生成途径，萘的逐级氯化可能是PCNs的主要生成途径，而PCDD/Fs、PCBs和PCNs的生成具有一定的相关性。本研究为饲料中二恶英类化合物污染的预防和控制提供了科学基础，也为降低动物性食品中二恶英类化合物的污染提供了有力支撑。