Institute for Prevention and Occupational Medicine of the German Social Accident Insurance - Institute of the Ruhr-University Bochum (IPA), Bürkle-de-la-Camp-Platz 1, 44789 Bochum, Germany.
Toxicology. 2010 Feb 9;268(3):198-203. doi: 10.1016/j.tox.2009.12.016. Epub 2009 Dec 23.
Fuel additives can improve combustion and knock resistance of gasoline engines. Common additives in commercial fuels are "short-chain, oxygen containing hydrocarbons" such as methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE). Since these additives change the combustion characteristics, this may as well influence toxic effects of the resulting emissions. Therefore we compared toxicity and BTEX emissions of gasoline engine exhaust regarding addition of MTBE or ETBE. Non-reformulated gasoline served as basic fuel. This fuel was supplemented with 10%, 20%, 25% and 30% ETBE or 15% MTBE. The fuels were combusted in a gasoline engine at idling, part load and rated power. Condensates and particulate matter (PM) were collected and PM samples extracted with dichloromethane. Cytotoxic effects were investigated in murine fibroblasts (L929) using the neutral red uptake assay and mutagenicity using the bacterial reverse mutation assay. BTEX emissions were analyzed by gas chromatography.
PM-extracts showed mutagenicity with and without metabolic activation. Mutagenicity was reduced by the addition of MTBE and ETBE, 10% ETBE being most effective. The condensates produced no significant mutagenic response. The cytotoxicity of the condensates from ETBE- and MTBE-reformulated fuels was reduced as well. The BTEX content in the exhaust was lowered by the addition of MTBE and ETBE. This effect was significantly related to the ETBE content at rated power and part load.
Addition of MTBE and ETBE to fuels can improve combustion and leads to decreased toxicity and BTEX content of the exhaust. Reduction of mutagenicity in the PM-extracts is most probably caused by a lower content of polycyclic aromatic hydrocarbons.
燃料添加剂可以改善汽油发动机的燃烧和抗爆性能。商业燃料中的常见添加剂是“短链、含氧烃”，如甲基叔丁基醚（MTBE）和乙基叔丁基醚（ETBE）。由于这些添加剂改变了燃烧特性，这也可能影响到排放物的毒性。因此，我们比较了添加 MTBE 或 ETBE 对汽油发动机废气毒性和 BTEX 排放的影响。未改制的汽油作为基础燃料。该燃料中添加了 10%、20%、25%和 30%的 ETBE 或 15%的 MTBE。这些燃料在怠速、部分负荷和额定功率下在汽油发动机中燃烧。收集冷凝物和颗粒物（PM），并用二氯甲烷提取 PM 样品。用中性红摄取试验研究了细胞毒性，用细菌回复突变试验研究了致突变性。通过气相色谱分析 BTEX 排放。
PM 提取物在有或没有代谢激活的情况下均显示出致突变性。添加 MTBE 和 ETBE 可降低致突变性，其中 10%ETBE 效果最明显。冷凝物没有产生显著的致突变反应。用 ETBE 和 MTBE 改制的燃料的冷凝物的细胞毒性也降低了。添加 MTBE 和 ETBE 可降低废气中的 BTEX 含量。这种效果与额定功率和部分负荷时的 ETBE 含量显著相关。
向燃料中添加 MTBE 和 ETBE 可以改善燃烧，并降低废气的毒性和 BTEX 含量。PM 提取物致突变性的降低很可能是由于多环芳烃含量降低所致。
