internal label的用法和样例：
例句
- Weakness of trace impouring imprecisely was avoided by mixing UDMH and internal standard solution.
用内标与偏二甲肼混合样品，避免了微量进样不准确的缺陷。 - Besides, quantitation analysis of involatile compositions in beer could be done by internal standard method or by external standard method.
还可用内标法和外标法对啤酒中的不挥发组分进行定量检测分析。
