O.I. Analytical Flow Solution IV analyzer


In use from 2004-04-01 to 2014-06-30


The O.I. Analytical Flow Solution IV analyzer is an automated continuous-flow colorimetric analyzer used for the analysis of NO3^- , NO2^- , NH4^+ , and PO4^= in soil extracts and water samples . Our configuration consists of the RA Sampler (X-Y-Z random access autosampler), Model 502 pump, Expanded Range (ER) Detector, and ALPKEM WinFLOW V4 software. 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 www.oico.com)



  1. Remove reagents, wash solution, and stock standards from refrigerator and allow to them come to room temperature.
  2. Turn on main power switch on front of Flow Solution IV Powerbase.
  3. Inspect tubing at pump site for failure.
  4. Inspect plumbing for proper connections.
  5. Open valve on nitrogen gas pillow.
  6. Clamp platens down on pump, pull platen levers up to apply pressure to tubes and start pump. Normal operating speed and direction is –40.00.
  7. Immerse wash pump tube in nanopure water (~1L).
  8. Attach all other reagent pump tubing to wash bucket containing nanopure water (with 1mL Brij 35 (30%)/ 1L).
  9. 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.
  10. Open WinFLOW program and start data collection while pumping water through system. Allow water to flow through system until it stabilizes with a regular bubble pattern. While waiting, prepare reagent bottles, standards, and sample table(s).
  11. 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.
  12. 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 (-5.00) insert coil between ports two and ten, on the cartridge. Then set pump speed back to normal 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).


  1. If nitrate is being run, disconnect cadmium-reducing coil by first setting the pump speed at –5.00. Then disconnect coil between cartridge ports two and ten (be careful not to introduce oxygen or ambient air into coil) after re-connecting ports two and ten, return pump speed to normal.
  2. Take all reagent lines off reagents and put them on nanopure water (with 1 mL Brij 35 (30%)/ 1L) allow the system to rinse thoroughly (about 10-20 minutes depending on chemistries being used). If KCl is used for wash, wash line must be rinsed with water also (no Brij).
  3. After the system has been rinsed disconnect all input lines (including the wash line).
  4. Shut off the pump and release platen levers and platens. Do NOT leave tension on pump tubing with pump off, this will ruin the tubing.
  5. Turn off the main power switch.
  6. Close valve on nitrogen pillow.
  7. Dispose of all waste by-products promptly and correctly:
    1. Dispose of ammonia waste and contaminated ammonia reagents in labeled hazardous waste container in the hood.
    2. Dispose of nitrate waste by neutralizing pH with 10N NaOH then dump down drain with lots of water. Watch for color change from pink to peach/orange.
    3. Dispose of contaminated solids (paper towels etc.) appropriately.
    4. If waste and/or reagents cannot be disposed of LABEL CLEARLY and leave in hood.
  8. Rinse cadmium coil with 10mL barnstead water (no Brij) and store with water in. Use a luer lock connector and syringe. Be careful not to introduce air into the coil.
  9. Store all reagents, standards and samples appropriately.
  10. Leave work area in neat and clean condition-appropriate for others to work in common courtesy and the Golden Rule.

Date modified: Thursday, Nov 16 2023



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