w*****u
发帖数: 857 | 1 I just developed a new method using LC/MS/MS, but when injecting the same
standards (tried same vial and different vials), the peak area is very
different from run to run, also the peak shape becomes horrible after a few
injections. Anyone knows any possible reasons? Thanks! |
g*****x
发帖数: 3283 | |
G***O
发帖数: 839 | 3 把方法和样品的情况说明一下。我估计是不是样品把柱子搞坏了。
：I just developed a new method using LC/MS/MS, but when injecting the same
：standards (tried same vial and different vials), the peak area is very |
w*****u
发帖数: 857 | 4 I tested another method, and injected the same solution several times, and
it was fine.
I switched to another column today.
Would the column also contribute to the intensity difference?
same
【在 G***O 的大作中提到】
: 把方法和样品的情况说明一下。我估计是不是样品把柱子搞坏了。
:
: ：I just developed a new method using LC/MS/MS, but when injecting the same
: ：standards (tried same vial and different vials), the peak area is very
|
T********1
发帖数: 105 | 5 Could you specify what are the differences between the two methods? |
G***O
发帖数: 839 | |
a****a
发帖数: 389 | 7 搞了很多testing，现在认为可能是quadruple里面有charging，需要cleaning。
两个方法最大的不同之处就是一个是positive mode，一个是negative mode。
现在仪器就是negative mode很好，positive mode就不stable。
[在 GUXBO (gxb) 的大作中提到：]
:Any updates on why ? |
p*******w
发帖数: 311 | 8 Can you try positive mode with a different method that has been proved
working before?
Matrix effect or your column is dirty.
If you have charging effect on your quadruple, just run the tuning solution
at positive mode for a while, your TIC will start high and then tail down
significantly. It wouldn't stay as a straight line. |
t********e
发帖数: 107 | |
