johne0212
第4楼2013/02/01
LC/MS/MS做S/N比有几种不同的算法,通常我们使用的是下面两种,但是每种算法都是估测值,推荐你计算出来以后在去验证一下。
1.通过S/N去算
首先需要空白基质,然后在空白基质上添加3个尽量接近LoD浓度水平的被分析物。每个浓度水平平行分析2次,计算每次的S/N,然后以添加浓度为横坐标,S/N为纵坐标,进行线性回归,得到方程,当Y=3时计算的X值就是LoD,当Y=10时,X为LoQ。具体例子如下。
LoD & LoQ | Height | S/N |
Spiked 3ppb-1 | 6 | 5.56 |
Spiked 3ppb-2 | 5 | 4.63 |
Spiked 6ppb-1 | 16 | 14.81 |
Spiked 6ppb-2 | 15 | 13.89 |
Spiked 8ppb-1 | 20 | 18.52 |
Spiked 8ppb-2 | 22 | 20.37 |
Cal Value(ppb) | ||
LoD | 2.22 | |
LoQ | 4.64 |
zwyu
第5楼2013/02/01
mark
LoD & LoQ | Height | S/N |
Spiked 3ppb-1 | 6 | 5.56 |
Spiked 3ppb-2 | 5 | 4.63 |
Spiked 6ppb-1 | 16 | 14.81 |
Spiked 6ppb-2 | 15 | 13.89 |
Spiked 8ppb-1 | 20 | 18.52 |
Spiked 8ppb-2 | 22 | 20.37 |
Cal Value(ppb) | ||
LoD | 2.22 | |
LoQ | 4.64 |
suyirumo
第6楼2013/02/02
大神在这里 学习了 一直想弄明白这个问题
goldendays
第7楼2013/02/04
请问第二种方法里,连续测试空白基质,是计算其噪音吗?然后计算6次进样的噪音的SD值?
LoD & LoQ | Height | S/N |
Spiked 3ppb-1 | 6 | 5.56 |
Spiked 3ppb-2 | 5 | 4.63 |
Spiked 6ppb-1 | 16 | 14.81 |
Spiked 6ppb-2 | 15 | 13.89 |
Spiked 8ppb-1 | 20 | 18.52 |
Spiked 8ppb-2 | 22 | 20.37 |
Cal Value(ppb) | ||
LoD | 2.22 | |
LoQ | 4.64 |
makfe
第10楼2013/02/24
LoD & LoQ | Height | S/N |
Spiked 3ppb-1 | 6 | 5.56 |
Spiked 3ppb-2 | 5 | 4.63 |
Spiked 6ppb-1 | 16 | 14.81 |
Spiked 6ppb-2 | 15 | 13.89 |
Spiked 8ppb-1 | 20 | 18.52 |
Spiked 8ppb-2 | 22 | 20.37 |
Cal Value(ppb) | ||
LoD | 2.22 | |
LoQ | 4.64 |