摘要
用酚二磺酸法和紫外光法测定蔬菜中的硝酶盐含量,并对酚二磺酸法的测定条件进行了比较试验,结果表明,2种方法均可用于蔬菜硝酸盐含量的测定,但以酚二磺酸法测定的结果最稳定;当缺组织捣碎机时,人工研磨制备样液及电炉煮沸浸取样液,能较好地提取出硝酸盐;活性炭确能吸附一定数量的硝酸盐。按本法操作,每个样品活性炭的允许用量为0.5g;样液蒸干时不加碳酸钙,将水浴温度控制在80℃以内,并不影响硝酸盐的测定结果。
The study showed that both phenoldiulphonic acid colorimetric method and ultroviolet spectrophotomter method were Suitable for determining nitrate in vegetables and the former could obtain more stable results than the latter,Nitiate could be extracted perfectly from vegetable by grinding plant manually,if plant tissue smashing machine was not avaiable,and then heated in electric stove.Nitrate absorption by activated carbon,to some extent,was also observed,suggesting that the limited rate of activated carbon added should be 0.5g in an extract and the temperature from evaporating to drying should be less than 80℃.The tested rettults were not affected even if calcium carbonate was not added to the extract aquiot.
关键词
叶类蔬菜
硝酸盐
残留物
分析法
vegetable crops
nitrate
residue analysis
analytical methods
