Thermo Scientific Surveyor MS Pump, Hardware Manual, Page: 47 / 100

3
Diagnostics
Testing the Pump Proportioning
Thermo Scientific Surveyor MS Pump and Surveyor MS Pump Plus Hardware Manual 31
Testing the Pump Proportioning
You need to test the proportioning accuracy of the pump periodically by running a
step-gradient.
Two eluents, methanol and spiked methanol, are used in this procedure. The absorbance
reading for the 100% spiked methanol solution should be in the 600 to 800 mAU range.
• If your detector contains a standard 10 mm flow cell, prepare the spiked methanol
solution by adding 7 mg of ethyl paraben (P/N A4904-010) to 1 L of HPLC grade
methanol.
• If your detector contains a 50 mm LightPipe flow cell, prepare the spiked methanol
solution by adding 1.4 mg of ethyl paraben to 1 L of HPLC grade methanol.
The step gradient program is shown in Table 2 . Use the following conditions to run the step
gradient:
• Flow: 200

L/min
• Pressure: approximately 100 bar by restriction
• Eluents: A: methanol
B: spiked methanol
• Sub-proportioning: Off
• Steps: 10 min hold, 20% increments
• Detection: UV (254 nm)
Table 2. Gradient Program
Time (min) %A %B
0.00 100.0 0.0
10.0 100.0 0.0
10.01 80.0 20.0
20.0 80.0 20.0
20.01 60.0 40.0
30.0 60.0 40.0
30.01 40.0 60.0
40.0 40.0 60.0
40.01 20.0 80.0
50.0 20.0 80.0
50.01 0.0 100.0
60.0 0.0 100.0