impurity
词根词缀：
expurgate v. 删除
ex 使… + purg 纯洁；变干净 + ate 做，造成，使… → 变干净 → 删除
impure adj. 不纯的
im 不 + pure 纯的；纯洁的 → 不纯的
impurity n. 不纯；有罪
im 不 + purity 纯净 → 不纯；有罪
pure adj. 纯的；纯洁的
purgation n. 清洗
purg 纯洁；变干净 + ation 行为，过程，状态，结果 → 使干净 → 清洗
purgative adj. 清洗的
purg 纯洁；变干净 + ative 有…倾向（性质）的，属于…的 → 清洗的
purgative n. 泻药
purge v. 使清净
purify v. 使清洁；使纯正
pur 纯洁；变干净 + ify 使… → 使纯洁
purist n. 纯粹主义者
pur 纯洁；变干净 + ist 信仰某种信仰、主义的人 → 纯粹主义者
purity n. 纯净
pur 纯洁；变干净 + ity 具备某种性质，状况 → 纯净
unpurged adj. 未净化的
un 没有 + purg 纯洁；变干净 + ed 表形容词 → 未净化的
数据来源：新东方英语词汇速记大全
相关例句：
Rinse under cold water to wash away the blood and impurity.
再用冷水冲去血沫和杂质。
The effect of HCl, an impurity in flue gas, on the activity of the catalysts was evaluated.
并考察了烟气中可能杂质氯化氢对催化活性的影响。
Some impurity as well as bromine was brought by solid matter that smuggled with foam fog in flash steam.
闪蒸气中雾沫夹带的固体物引入了溴等杂质。
The impurity elements on the surface of the silicon sample corroded were analyzed by an energy dispersive spectroscope.
用能谱仪对腐蚀后的硅表层杂质元素进行分析；
In this study, through the impurity distribution, organization and resistivity analysis, it evaluates the directional solidification purification effect on the polysilicon in the round.
本实验通过对提纯后硅铸锭的杂质分布、组织及电阻率分析，系统评价了定向凝固方法对多晶硅提纯效果。
The oxidizing roast of high impurity ferromolybdenum was studied by using rotary kiln.
采用回转窑加热的方法对高杂质钼铁（合金）氧化焙烧进行了研究。