Alpkem Model 3550 Flow Analyzer


to 2004-04-01


The Alpkem 3550 Flow analyzer is an automated continuous-flow colorimetric analyzer used for the analysis of NO 3 - , NO 2 - , NH 4 + , and PO 4 = in soil extracts and water samples . Our configuration consists of the Model 501 XYZ sampler, Model 502 pump, Model 503 Cartridge heater, Model 504 Power Supply, Model 505 Filter Photometer, Model 509 Power Distribution Module, Model 510 Monochromator Detector, Model 511 Dilutor, Model 512 Valve Module, New Analyzer Program (NAP) Software, and Super Cartridges (2 for NO 3 - , 2 for NH 4 + , 1 for Phos/orthoPhos, 1 for Silicates) . Further information about the analyzer can be obtained from OI Analytical (OI Analytical, 151 Graham Road, P.O . Box 9010, College Station, TX 77842 or .


  1. Turn on power switches: PC and monitor (if necessary), main sampler/diluter, detectors (2), and appropriate hot plate (if needed)
  2. Inspect tubing at pump site for failure.
  3. Inspect plumbing for proper connections: sampler, wash line, nitrogen lines, pump tubing, cartridges, detectors, waste lines and de-bubbler pull-off tubes (especially).
  4. Turn on nitrogen gas at tank stem and at ¨?T¨? valve. You will have to coordinate with anyone using the gas mixing bench as these all use the same nitrogen tank. Make sure you don’t turn the nitrogen off on anyone (or more importantly they on you).
  5. Connect nitrogen pump tubing at regulator above peristaltic pump (if necessary).
  6. Immerse wash pump tube and diluter lines (2) in nanopure water (~1L)
  7. Attach all other reagent pump tubing to wash bucket containing nanopure water and ~20 drops of Brij 35 (30%)
  8. Clamp platens down on pump, pull platen levers up to apply pressure to tubes and start pump (normal speed 50 liquid should be observed moving through all appropriate tubes. If movement is not observed check for improper connection, possible faulty tube or blockage in tube, sample probe or cartridge.
  9. Allow water to flow through system until it stabilizes with a regular bubble pattern. While waiting, prepare reagent bottles, standards, sample table(s), and set up software.
  10. Turn on the computer, screen and printer (if necessary).
  11. Click on the icon labeled ¨?NAP¨?
  12. Click OK, (registration is only necessary once a year).
  13. Create the sample table: select Sample Table from the menu bar.
  14. Print a copy of the sample table and check for accuracy, select File, Print.
  15. When everything is correct, save the table, select File, Save As. there is an eight character limit for the filenames. for non-LTER files, we ask that the first letter of the filename be representative of you project/name. For LTER inorganic-N analysis files use the following formula with the sample date: YYYYMMDD. For LTER lysimeter analysis files use this formula: QYYMMDD.
  16. Connect reagents and wash with appropriate pump tubes and wait for baseline to stabilize. Continue by aligning samples with the sample run sequence table and with any other preparations for the run. Make sure there are no bubbles trapped in the detector flow cells.
  17. Cadmium Coil test: If nitrate is being run, now is the time to attach the cadmium coil. Make sure there is minimal oxygen (ambient air) being introduced through lines. With pump on minimum speed insert coil between ports one and ten, on the cartridge. Then set pump speed back to 50 and allow bubbles to stabilize. After the cadmium coil is connected and the bubbles are acceptable, check the coil efficiency and peak repeatability by sampling working nitrate and nitrite standards of equal concentrations (usually 8ppm). This can be accomplished by using the sample table labeled “coiltest” with corresponding data files. Bring up the “coiltest” sample table and follow for cup placement. Start test by returning to the main window and selecting the “coiltest” sample table by either entering the name in the Filename box or clicking the arrow to the right and selecting it from the list. If the data fields are empty, the appropriate data files should appear in the data file boxes automatically. After the files are entered, press the Stand By button and check the baselines by clicking on the View option in the menu bar. When the baselines are acceptable, you exit back to the main window and press the On button. Select View to monitor the run. Peak height measurements appear on the Channel Display screen. Reach this window by double clicking on the graph window or highlighting the graph window and clicking Edit from the menu bar.

Date modified: Tuesday, Aug 29 2023



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