Home / Standards / GB/T 223.37-1989 GB/T 223.37-1989 Abolished Methods for chemical analysis of iron，steel and alloy--The indophenol blue photometric method for the determination of nitrogen content after distillation separation 钢铁及合金化学分析方法 蒸馏分离-靛酚蓝光度法测定氮量 Standard Type GBT ICS 77.080 CCS H11 Status 废止 Issue Date 1989-03-31 Implementation 1990-07-01 Responsible Dept 中国钢铁工业协会 Drafting Unit N/A