Baseline noise and drift issue. G4212B Max light.

Question

Dear team, 
 We have an G4212B DAD detector. We have an issue with baseline. Please see below. It's water 1 ml/min. 254 nm (4mm), reference 500 (100mm) 
 
 below results flow off, Max light Cell 10 mm. 
 
 below results flow off, Max light Cell 60 mm. 
 
 We flushed the flowpath for two days: IPA, MeOH and water. We have tried with column and with zero dead volume fitting. 
 What could be the possible source of such drift and noise in baseline? 
 Thank you all in advance. 
 Kind regards, Rustam

sschombu · Accepted Answer

Not sure which quat pump you're using, but your pressure is too low. When it comes to testing, I would always have the 2m stainless steel restriction capillary installed. To find out more (whether the cell, the lamp, the optics etc. are to blame), you'll have to exclude the cell first. However, G4212X/G7117X detectors cannot be operated without cell. Either you go for the test cell, which is operated without liquid flow, or you have another, known good, Max-Light flow cell. 
 
 You could also try following the "Cleaning of Max-Light Cartridge Cell" section in the user manual.

Baseline noise and drift issue. G4212B Max light.

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