Chromatography Forum

Dear All

I use waters 2487 UV detector for analysis nucleic acid.
I never turn the detector off for 3-4 mounths because analysis time is too long and many sample.So I get a ploblem! Normally IDP peak is higher than GDP peak but recently IDP is smaller. Is that because of turn off time? If yes, how to know? because this analysis procedure is very important for QC my product.

Thank you for your help!

Power your detector off, wait 30 seconds turn it back on. Two things happen, 1st, the on-board diagnostic run, this will tell you if it is working or broken. Second, it will invoke lamp optimization, which is a process where the detector sets its lamp energy so that you get the same peak height from an old lamp and new lamp. So in the future, it would help you to turn the unit off ond back on once in a while (maybe weekly). Your results will be more consistant.

Kasiban,

I agree with AA, you need to let the detector run its self-diagnostics. Ours Waters rep. once told us to do either a complete shut down or to manually run the diagnostics (the manual gives the instructions) at least once a month.

Also, note that leaving the lamp on continuously will lead to a very short life-time for the lamp and its early replacement. As the lamp ages you can have detection problems. The lamp can be shut off in the programming of the detector or you do it manually from the front panel controls.

Regards,
Dan