题干

下列关于测定亚硝酸盐含量原理的叙述,不正确的是(    )

A:亚硝酸盐经一定方式显色反应后呈玫瑰红色

B:显色反应后亚硝酸盐的理化性质没有发生改变

C:不同浓度的亚硝酸盐显色深浅不同

D:样品液显色后,通过与已知浓度的标准液比色,可大致估算出样品液中亚硝酸盐的含量

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B

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