Troubleshooting Tips

This section is designed to help you quickly find the solution you are looking for.

Click on the appropriate link for answers regarding that particular topic.

TOPICS

A. Atomic Absorption Spectrometer (AAS)

B. Inductively Coupled Plasma (ICP)

C. Polarimeter

D. Spectropolarimeter

E. Spectrophotometer

F. Fourier Transform Infrared Spectrometer

G. HPLC

H. Mass Spectrometer

I. Purge and Trap

J. Computer

SOLUTIONS

A. Atomic Absorption Spectrometer (AAS)

1. Absorbance value is low.

• Align the Hollow Cathode Lamp position
• Align the Burner lateral and rotational position and the height
• Align the Deuterium lamp position
• Optimize the Nebuliser impact bead position
• Clean the Nebuliser
• Check the gas flow and pressure settings
• Align the Furnace if installed

2. Optical setup failed when using a particular lamp.

• Align the lamp position
• Replace with a new lamp

3. The flame cannot be ignited.

• Check for presence of igniter sparks at the burner head
• Adjust igniter position
• Check gas flow and pressure settings

4. The baseline is high when using the furnace.

• Clean the furnace head windows

5. The cuvette lifetime is shorter than normal when using the furnace.

• Clean the Temperature Control window

6. The analytical precision has worsened after some use of the furnace.

• Check the worn out cuvette contact cones

7. How to minimize contamination when using the furnace.

• Avoid handling cuvette by hand
• Choose the right composition for the wash liquid
• Change the wash liquid regularly
• Clean the sample and reagent cups regularly
• Purge the Autosampler

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B. Inductively Coupled Plasma (ICP)

8. A communication error occurs when starting the application.

• Reseat the interface cable connection at the rear of the computer

9. The intensities for some elements are lower than before.

• Check the mist from the nebuliser
• Perform an Auto Peak Adjust
• Perform a full frame image capture and check the mapping position
• Check the sub-array plot

10. The sample uptake is not constant.

• Adjust the tension for the pump windings
• Check that the peristaltic pump is rotating smoothly

11. There is little mist from the nebuliser.

• Replace the sample filter
• Replace the pump windings
• Check for clog in the nebuliser
• Replace the nebuliser

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C. Polarimeter

12. The optical rotation reading is fluctuating.

• Select the aperture size smaller than the cell internal diameter, e.g. if the cell internal diameter is 10mm, select 8mm aperture
• Check whether the filter is cloudy
• Replace with a new lamp

13. When running the measurement program, the Mercury lamp automatically turns off and the Sodium lamp turns on.

• You must be logged on to the computer with Administrator rights

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F. Fourier Transform Infrared Spectrometer

18. What solvent should I use to clean the sample chamber?

• Clean it with a cloth dipped in water or soap water.
• Do not use organic solvent.

19. The background spectrum disappears intermittently.

• Check whether there is vibration to the instrument

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G. HPLC

20. There are air bubbles in the solvent delivery tubing.

• Clean or replace the solvent intake filter
• Use a degasser for the solvent

21. No peaks are detected.

• Clean or replace the pump outlet filter
• Purge the Autosampler metering pump of air bubbles

22. Backpressure is higher than normal.

• Clean or replace the in-line filter
• If a nebuliser is used in the detector, flush it for a longer time to clear any clog

23. Baseline is noisy.

• Condition the column

24. Unable to attain normal operating pressure.

• Check for leaks
• Remove detector flow cell and check for damage

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H. Mass Spectrometer

25. The system fails while you were running samples.

• There may be a hardware failure. Run diagnostics.

26. The problems occur immediately after you performed maintenance on the system.

• The problem is probably mechanical, not electrical. Verify that alignment is correct before you run Diagnostics

27. The fore pressure is too high due to solvent peak.

• Reduce injection volume or extend filament/multiplier delay time until after solvent peak.

28. The GC did not start.

• Verify GC methods and configuration. Verify connection between Autosampler and GC.

29. Acquisition terminates unexpectedly.

• The End Run time in the Instrument Setup file is incorrect.
• The data system is out of disk space.

30. There is excessive chemical background due to column bleed (m/z 429, 355, 281).

• Capillary column has not been properly conditioned.
• Capillary column is damaged as a result of exposure to oxygen.
• Capillary column is broken off in ion volume.

31. There is excessive injection port septum bleed (Typical m/z 207, 429, 355, 281).

• The septum is worn out or damaged.
• Small pieces of septum are in the injection port liner.

32. Automatic Tune reports “Air leak has been detected”.

• Loose transfer line nut or union
• Dust or debris on the top cover o-ring
• No helium flow from the GC. This causes the detector to suck air through the column.

33. Rotary-vane pump turns on but will not pump down.

• The oil level in the rotary-vane pump is insufficient.
• The foreline is leaking. Check the clamps and connectors.
• The vacuum manifold top cover is leaking.

34. Turbomolecular pump will not turn on.

• The fore pressure is not low enough. Check the rotary-vane pump and foreline plumbing for leaks and proper operation.

35. Poor sensitivity or sudden loss in sensitivity.

• The wrong type of ion volume is installed. EI and CI require different ion volumes.
• The ion volume is incorrectly positioned.
• There is a large air leak. Run Leak Check in Automatic Tune or look for m/z 28 as base peak in full scan.
• The injector or septum is leaking.
• GC column is not inserted beyond end of transfer line or GC column is broken off in ion source.
• The ion volume, lenses, or prefilter are dirty.
• The instrument is out of tune, or tune file is incorrect.
• The magnets above and below the ion source are installed incorrectly.
• Reagent gas is leaking into the analyzer, suppressing EI signal.
• Incorrectly matched syringe, injection port liner, and column depth in injector.
• Insufficient sample delivery due to plugged syringe needle.
• The injection port liner is contaminated.
• Graphite or septa particles contaminate the injection port.
• The capillary column is at the end of its life span.
• Method development problems are present.

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I. Purge and Trap

36. Tips for Reducing the Effect of Moisture in Compound Responses.

• Replace trap
• Increase Dry Purge time
• Never heat water samples unless absolutely necessary
• Use columns with a small I.D. and adjust flow accordingly to optimize Desorb flow
• Frequent changing of mechanical pump oil of the Mass Spectrometer

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J. Computer

37. Parts of the window could not be seen on the screen.

• Check that the correct screen resolution is selected in the Display Control Panel
• Install the correct video driver for the display card

38. There is an intermittent blue screen with some error messages.

• Run the Diagnostic CD that came with the computer to check for hardware failure

39. There is no response from the keyboard or mouse.

• Swap with known good keyboard or mouse
• There may be a motherboard failure

40. There is a screeching sound coming from inside the computer.

• The internal fan may need replacement
• The hard disk may be failing soon

41. The computer is slow.

• Try increasing the memory

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