我们于 1999年 6～ 7月对广州市区 38个不同居民用水点取水喉水样 38份 ,并用国标 GB/ T85 38— 1995中重氮偶合比色法 〔1〕测定水样中亚硝酸盐的含量。测得 38份水样的亚硝酸盐 (以 NO- 2 计 )的平均值为 0 .41mg/ L,最小值为 0 .0 0 2 5 mg/L ,最大值为 1.48mg/ L。天然水中 In June-July of 1999, we collected 38 water samples from 38 different households in Guangzhou City and measured the contents of nitrite in water sample by GB / T85 38-1995 diazotization method [1] Content. The average value of nitrite (NO2) of 38 water samples was 0.41 mg / L, the minimum value was 0.0025 mg / L and the maximum value was 1.48 mg / L. Natural water