auto Injector_linearity

[mohammad]

Dear all,

I am having problem with auto injector (Shimadzu), the calibration results are given below:

injection volume Average Area (5 injections)
10µL 6049443
20µL 11902452
30µL 18135529
40µL 21045159
50µL 24891309

from the above results its very clear that the from 40µ onward the response is very low hence the coefficient corelation is failing.

Can any 1 suggest me the remedy....

Regards
Mohammad

[novus]

Did you known the linearity range of the coffeine solution concentraion?
You can reduce the concetration of the test solution and try again.

[tom jupille]

Also, what size loop is installed on the injector. Because of "laminar flow" effects, it is not unusual to loose some sample when your injection volume gets above about half of the loop volume.