CAD OQ - Noise Test Failing

Issue

Trouble getting Noise test to pass for CAD qualification.

Environment

• Qualification (OQ)
• Corona Veo Charged Aerosol Detectors (CAD)
• Vanquish CAD

Resolution

Use better water for the test.

A highly pure water such as:

Fisher Plasma Water (1L): 080157

Agilent Ultra Pure  Water for HPCE (500mL): THRAG-5062-857

Details: https://www.agilent.com/store/undefi...8578/5062-8578

Can be ordered through Cloud 4 Service if the customer doesn't have suitable water on hand.

Analysis

Using a higher quality of water can help achieve significantly better Noise and Drift values. Most laboratories do not have pure enough water for testing.

Also, always make sure the instrument has had a proper PM (if not new), and confirm no environmental factors (HVAC, for example) are not affecting the unit's operation as these can impact the drift test as well.

Cause

CAD instruments are highly sensitive to the quality of water, and require a higher purity than most LC detectors.