Inconsistent recovery with ACQUITY SM-FTN - WKB109436

SYMPTOMS

• Recovery of internal standard is inconsistent
• High %RSD for peak height recovery for the internal standard
• Sample syringe leak test passes
• No clogs in inject valve or needle
• Leak test of the pump passes
• Leak test of the needle and seal passes
• Replacing the Vespel seal does not resolve the issue

ENVIRONMENT

• ACQUITY H-Class SM-FTN
• ACQUITY I-Class SM-FTN

CAUSE

The tip of the needle is touching the bottom of the sample vial, causing inconsistent recovery of the sample.

OR

The tip of the needle is damaged.

FIX or WORKAROUND

Replace the sample needle:

• 15 µL SS needle (H-Class): 700005215
• 15 µL textured needle (H-Class PLUS & I-Class PLUS): 700011628
• 15 µL MP35N needle (H-Class Bio): 700005421
• 15 µL MP35N textured (H-Class Bio PLUS): 700011658
• 30 µL SS needle (H-Class & I-Class): 700005279
• 30 µL textured needle (H-Class PLUS & I-Class PLUS): 700011698
• 15 µL SS needle (I-Class): 700008977

Recalibrate the needle Z-axis.

ADDITIONAL INFORMATION