滴定管Burette

酸式滴定管下端为玻璃活塞，用于盛装酸性、中性和氧化性溶液（如 KMnO₄、I₂、AgNO₃），不能盛碱液（碱会腐蚀磨口使活塞粘住）；碱式滴定管下端为橡胶管内装玻璃珠，用于碱性溶液，不能盛氧化性溶液（会腐蚀橡胶）。现在常用聚四氟乙烯活塞的通用滴定管，酸碱都可盛装。见光易分解的溶液用棕色滴定管。

Acid burettes have a glass stopcock and hold acidic, neutral and oxidising solutions such as KMnO₄, I₂ and AgNO₃, but not alkalis, which etch the ground joint and seize it; base burettes have a rubber tube with a glass bead and hold alkaline solutions but not oxidants, which attack the rubber. Universal burettes with PTFE stopcocks now hold both. Light-sensitive solutions go in brown burettes.

使用前检漏、洗净，用待装溶液润洗 2–3 次；装液后排出尖嘴气泡，调至零刻度或附近；读数时视线与弯月面最低点（深色溶液读上沿）相平，读到小数点后两位；滴定时左手控制活塞，右手摇动锥形瓶，近终点时逐滴甚至半滴加入；平行测定的体积差一般不超过 0.02–0.04 mL。

Check for leaks, clean, and rinse two or three times with the titrant. After filling, expel air from the tip and set the level at or near zero; read with the eye level with the bottom of the meniscus (the top for dark solutions) to two decimal places. Control the stopcock with the left hand while swirling the flask with the right, adding dropwise or half-drops near the end point; replicate titres should usually agree within 0.02–0.04 mL.

1791 年法国化学家德克鲁瓦西尔首先使用类似滴定管的装置进行容量分析。1824 年盖-吕萨克改进滴定管并创造了 pipette 和 burette 两词。1855 年莫尔设计了带夹子的碱式滴定管，奠定了现代滴定管的形式。

In 1791 the French chemist Descroizilles first used a burette-like device for volumetric analysis. Gay-Lussac improved it in 1824 and coined the words pipette and burette, and Mohr designed the clip-controlled burette in 1855, setting the modern form.