Answer / amol

because , when manufacturing of column is done different
parameter is affected which is given below , due to this
each column is unique tho it is same type.

column parameter

column pressure
parical size
carbon density
dead voulume of the column
end fitting
end capping of the column.
silica used.

Hplc System Parameter

length of tubing.
internal dia. of tube.
void volume of system.
pump working.
flow rate.
end fittings.
ETC....

Answer / satheesh kumar

In HPLC same type of columns means say C18,there are lot of
brands C18 columns available in market namely
inertsil,Symmetry,X-Terra,phenomenex gemini,Zorbax etc.,

Each columns are not similar in packing and carbon
load.column chemistries will vary with one another.

Hence RT shift observed in same types of columns.

Answer / reet

following factors might be the reason:
1. Column ageing
2. how the column was preserved, or what mobile phase was
used before the present experiment
3. sample preparation might be the cause. sample may be non-
homogeneous
4. Slight variation in thepH may also affect the variation
in RT.
5. Other parameters like,temperature can also be one of the
reason.
6. last but an imporatant factor might be some air bubble
trapped in the system.

Answer / ranjit

it is depends upon polarity of the colunm

Answer / ali

The difference in RT is usually caused by column age and how
it was conditioned before the analysis.

Answer / ravi.a

it is depend on used mobile phase is one of the reason if u
get peaks area are same if not get same areas that column
is dameged due to in colun stationary phaes coming ot side

acceptance criteria for ph meter, hplc detector,pump,injector,oven when we calibrate.

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