Whitney Blackmon
Carlos VargasThis Information Applies To: Agilent Flame Atomic Absorption (AA) Spectrometers (50/55/240/280 AA)
Issue:
How to clean a blocked nebulizer of a Flame AA, which may be causing low sensitivity or a sample uptake rate below 5 ml/min.
Steps to follow:
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Warning: Never remove a nebulizer from the spray chamber while the flame is on. Always extinguish the flame before removing the nebulizer from the spray chamber. Parts in and near the burner compartment become hot during operation. To prevent severe burns, always allow parts to cool completely, or wear heat resistant gloves before handling.
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To clean a blocked nebulizer:
1. Remove the burner from the spray chamber and remove the spray chamber from the AA.
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2. Disassemble the nebulizer block components. See Figure 1 for description and part numbers of components.
3. Place the nebulizer capillary (item 26), capillary guide (item 8), and venturi (item 10) in an ultrasonic cleaner containing a 0.5% laboratory detergent solution, such as Decon-90, for 5 to 10 minutes.
4. If the ultrasonic bath fails to clear the blockage, pass a burr-free nebulizer cleaning wire (supplied with the nebulizer) carefully through the capillary guide, then repeat Step 3.
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Tip: The correct nebulizer cleaning wire can be ordered using part number 9910024700
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5. Rinse the nebulizer capillary, capillary guide, and venturi with a stream of distilled water from a wash bottle, then allow the components to dry completely (overnight if possible).
6. Check for a blockage in the plastic sample capillary tubing that connects to the nebulizer capillary. If there is a blockage, cut off the blocked section of the capillary, or fit new sample capillary tubing.
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Tip: Excessive shortening of the capillary tubing will increase uptake rate
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7. Re-assemble the cleaned and dried nebulizer block components. See Figure 1.
8. Re-assemble and reinstall the spray chamber to the AA and refit the burner to the atomizer. See Figure 2 for description and part numbers of components
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Tip: If any components appear damaged or worn, replace before refitting.
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Warning: Incorrect assembly and fitting of nebulizers to an atomic absorption spectrometer can create explosion hazards and fire hazards that can cause serious injury to personnel and damage to equipment and property.
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Figure 1: Nebulizer Components and Description
| Item | Description | Part Number |
| 3 | Spray chamber screw mounting | 1510226600 |
| 4 | Nebulizer block, fluorinated (excludes integrated nebulizer) | 9910093100 |
| 5 | Clamp bead adjuster | 810133400 |
| 6 | Screw bead adjuster | 1510225000 |
| 8 | Nebulizer capillary guide | 810134400 |
| 9 | Kit, fluorinated liquid trap, drain tube with integrated float and magnet | 9910105800 |
| 10 | Venturi nebulizer, PEEK | 1610117390 |
| 12 | Clamp bush guide | 810134300 |
| 13 | Screw capillary adjuster | 1510226800 |
| 14 | Nut lock M12 x 0.5 | 1510226700 |
| 15 | Bearing bush nebulizer | 310046600 |
| 16 | Screw lock dog point M8 | 1510226000 |
| 17 | Screw M6 x 6 Ertalyte | 1510226500 |
| 18 | Kit, fluorinated liquid trap, drain tube with integrated float and magnet | 9910105800 |
| 20 | Spring nebulizer | 4610017400 |
| 21 |
O-ring screw bead adjuster, nitrile O-ring screw bead adjuster organic solvent compatible |
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| 24 | O-ring 1/32 in id x 3/32 in od x 1/32 in nitrile | 6910009700 |
| 25 |
O-ring 3/16 in id x 5/16 in od x 1/16 in nitrile O-ring 3/16 in id x 5/16 in od x 1/16 in organic solvent compatible |
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| 26 | Nebulizer Capillary Kit Includes capillary assembly, capillary guide, nebulizer spring, nebulizer cleaning wire, Hi-Vac capillary tubing and standard capillary tubing | 9910093000 |
Figure 2: Mark 7 Spray Chamber Components and Description
| Item | Description | Part Number |
| 1 |
Mixing paddle, fluorinated, 1/pk Mixing paddles, fluorinated, 5/pk |
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| 2 |
Mark 7 air/acetylene burner Mark 7 nitrous oxide/acetylene burner |
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| Not Shown | Burner cleaning and alignment card, 100/pk | 9910053900 |
| 7 |
Spray chamber body, fluorinated |
6210092090 |
| 11 |
Pressure relief bung, fluorinated O-ring for spray chamber bung, nitrile for aqueous solutions O-ring for spray chamber bung, organic solvent compatible |
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| 18 | Kit, fluorinated liquid trap, drain tube with integrated float and magnet | 9910105800 |
| 22 |
O-ring spray chamber, nitrile O-ring spray chamber, organic solvent compatible |
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| 23 |
O-ring burner base, nitrile for aqueous solutions O-ring burner base, organic solvent compatible |
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Caution: Ensure that the nebulizer is correctly assembled and correctly fitted to the spray chamber before lighting the flame. Nebulizers should be correctly adjusted before lighting the flame.
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- After assembling the spray chamber and burner, optimize the Flame AA (see Flame AA Optimization)
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Warning: Regularly test all connections for leaks. Rectify all leaks before lighting the flame
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Learn how to effectively operate your Agilent Atomic Absorption System:
Agilent 240/280 Series AA (including Zeeman) User's Guide user manual on Agilent.com
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