R*j
发帖数: 248 | 1 经常看到有些LC/MS/MS的标准曲线不是线性的。然后作者用一些奇怪的方程去拟合。(
我理解加权是必要的)
谁能讲一下如果标准曲线不是线性的,那末用什末方程去拟合啊? |
R*j
发帖数: 248 | 2 哦,上面这个问题是指用LC/MS/MS定量.
【在 R*j 的大作中提到】
: 经常看到有些LC/MS/MS的标准曲线不是线性的。然后作者用一些奇怪的方程去拟合。(
: 我理解加权是必要的)
: 谁能讲一下如果标准曲线不是线性的,那末用什末方程去拟合啊?
|
b**u
发帖数: 2761 | 3 看一下最fit是什么方程.我以前用非线性算过, 不过不是LC/MS/MS, 哈哈. |
h*****t
发帖数: 1226 | 4 are you talking about PK results just simple concentration measurements for
starndard curve?
If latter, it should be linear but has limited dynamic range.
【在 R*j 的大作中提到】
: 经常看到有些LC/MS/MS的标准曲线不是线性的。然后作者用一些奇怪的方程去拟合。(
: 我理解加权是必要的)
: 谁能讲一下如果标准曲线不是线性的,那末用什末方程去拟合啊?
|
p*****n
发帖数: 26 | 5 As far as I know, you can use nonlinear equations like quadratic equations
to fit your data from LCMSMS. It is said that it is quite normal the
standard curve shows nonlinear property if your concentration range is large
. Softwares like Xcalibur LCQuan from ThermoQuest can be used.
【在 R*j 的大作中提到】
: 经常看到有些LC/MS/MS的标准曲线不是线性的。然后作者用一些奇怪的方程去拟合。(
: 我理解加权是必要的)
: 谁能讲一下如果标准曲线不是线性的,那末用什末方程去拟合啊?
|
R*j
发帖数: 248 | 6 谢谢. 因本版人气不旺, 我在化学版问了同样的问题.和你的解释类似. 再问个低级问
题. 可不可以把样品稀释到标准曲线的线性范围内,然后光用标准曲线的线性部分. 有
人这样做吗? 从实际操作的角度讲, 这样是不是更麻烦,或者引进更大的误差?
large
【在 p*****n 的大作中提到】
: As far as I know, you can use nonlinear equations like quadratic equations
: to fit your data from LCMSMS. It is said that it is quite normal the
: standard curve shows nonlinear property if your concentration range is large
: . Softwares like Xcalibur LCQuan from ThermoQuest can be used.
|
A*****s
发帖数: 813 | 7 可以稀释，自己做误差分析，比较一下
【在 R*j 的大作中提到】
: 谢谢. 因本版人气不旺, 我在化学版问了同样的问题.和你的解释类似. 再问个低级问
: 题. 可不可以把样品稀释到标准曲线的线性范围内,然后光用标准曲线的线性部分. 有
: 人这样做吗? 从实际操作的角度讲, 这样是不是更麻烦,或者引进更大的误差?
:
: large
|
h*****t
发帖数: 1226 | 8 You can dilute it and make it fix to the linear range, but you need do
replicants to access your dilution errors.
【在 R*j 的大作中提到】
: 谢谢. 因本版人气不旺, 我在化学版问了同样的问题.和你的解释类似. 再问个低级问
: 题. 可不可以把样品稀释到标准曲线的线性范围内,然后光用标准曲线的线性部分. 有
: 人这样做吗? 从实际操作的角度讲, 这样是不是更麻烦,或者引进更大的误差?
:
: large
|
c*x
发帖数: 235 | 9 If concentration is above calibration curve, you have to dilute it. But you
have to make dilution QC with same procedure and same dilution fold.
That's FDA guildline.
【在 R*j 的大作中提到】
: 谢谢. 因本版人气不旺, 我在化学版问了同样的问题.和你的解释类似. 再问个低级问
: 题. 可不可以把样品稀释到标准曲线的线性范围内,然后光用标准曲线的线性部分. 有
: 人这样做吗? 从实际操作的角度讲, 这样是不是更麻烦,或者引进更大的误差?
:
: large
|
R*j
发帖数: 248 | 10 I guess my question is: For those samples whose concentrations are beyond
the "Linear range" of standard curve in LC/MS/MS, can I dilute them to
linear range before analysis. Since linear curve makes more sense to most
people.
Apparently, another way is to establish a nonlinear standard curve which
covers the samples with high concentration.
Do you happen to know whether FDA agrees with nonlinear standard curve (e.g.
, quadratic equation)?
you
【在 c*x 的大作中提到】
: If concentration is above calibration curve, you have to dilute it. But you
: have to make dilution QC with same procedure and same dilution fold.
: That's FDA guildline.
|
c*x
发帖数: 235 | 11 If you you think nonliner fits, you have to proof that liner doesn't work
for your curve. You have to use the best fit.
g.
【在 R*j 的大作中提到】
: I guess my question is: For those samples whose concentrations are beyond
: the "Linear range" of standard curve in LC/MS/MS, can I dilute them to
: linear range before analysis. Since linear curve makes more sense to most
: people.
: Apparently, another way is to establish a nonlinear standard curve which
: covers the samples with high concentration.
: Do you happen to know whether FDA agrees with nonlinear standard curve (e.g.
: , quadratic equation)?
:
: you
|
