标准曲线是标准物质的物理/化学属性跟仪器响应之间的函数关系,它在浓度计算中起重要作用,那么如何用Excel作标准曲线,根据哪种指标判定标准曲线的好坏呢?下面我以氨氮浓度的测定为例介绍下自己的经验。
工具/原料
电脑
Excel 软件
方法/步骤
首先向Excel中输入氨氮标准浓度和相应的吸光值数据,如图所示:
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/b219ebc4b74543a9214884b20e178a82b9011478?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
请点击输入图片描述
对吸光值数据进行校正,使得零浓度对应的吸光值为零,如图所示:
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/eac4b74543a982266b9255599a82b9014a90eb79?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
请点击输入图片描述
以浓度值为横坐标校正吸光值为纵坐标作散点图,如图所示
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/0b55b319ebc4b745e1c7c968dffc1e178a821578?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
请点击输入图片描述
选中散点标志,右键单击,从条形工具框中选择添加趋势线
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/78310a55b319ebc4162b08e79226cffc1e171678?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
请点击输入图片描述
在设置趋势线格式中,选中显示公式,显示R平方值,如图所示:
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/42a98226cffc1e172cecf24f5a90f603738de979?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
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最后氨氮标准曲线就完成了,由R平方为0.9995可知,本次做的标准曲线质量是可信的。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/b64543a98226cffcbb79c1cca9014a90f603ea79?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
请点击输入图片描述