【摘要】 目的建立蔬菜中硝酸盐含量测定的酚二磺酸分光光度法。方法样品在沸水浴中加热15min,加入活性炭过滤提取,试样在无水情况下与酚二磺酸反应,生成硝基二磺酸酚,后者在碱性水溶液中生成黄色化合物,于410nm处用可见分光光度测定。结果方法线性范围0～10.0mg/L,相关系数r为0.999 5,方法检测限为1.12mg/kg,RSD为0.78%,加标回收率在95.0%～100.7%。结论该法测定蔬菜中硝酸盐含量的精密度和准确度较高,能够满足测定要求。更多还原

【Abstract】 Objective To establish a spectrophotometric method in vegetables with phenol disulfonic acid for the determination of nitrate.Methods To heat sample in a boiling water bath for 15 minutes,and activated carbon was added to filter and extract.The reaction was conducted with phenol disulfonic acid and the sample in the anhydrous case,and to generate the nitro-sulfonic acid phenol,the latter in an alkaline aqueous solution to form a yellow compound with visible absorption photometry at 410 nm.Results A good relationship was shown within the concentration of 0~10.0 mg/L(r=0.999 5),the detection limit(LOD) was 1.12 mg/kg,the relative standard deviation was 0.78 % with the recoveries ranged from 95.00~100.7 %.Conclusion It was a optimized method to determine nitrate in vegetables with good precision and accuracy,which was able to meet the requirements.更多还原