研究了食品用密封圈正己烷蒸发残渣量与样品的浸泡方法、截取方式、横切面数量、回流温度和冷凝回流完成后的处理等的关系，结果表明，浸泡方法、回流温度和冷凝回流完成后的处理等因素对蒸发残渣量影响明显，且蒸发残渣量随着横切面的增加而增大。研究影响因素的同时，给出了试验中每个环节的控制指标，保证了检验结果的可重复性和真实性。

The relation between evaporation residue of food-contact n-hexane obturating ring and treatment parameters, which included soak method, cut method, number of cross-section, reflux temperature, and treatment after condensation, was analyzed. The results showed that soak method, reflux temperature, and treatment after condensation are main influencing factors; evaporation residue amount increases with increasing cross-section. The control levels in each sector of inspection process were put forward to ensure repeatability and authenticity of inspection result.