1. GAINING EFFICIENCY UTILIZING “NEW” ANALYTICAL TECHNOLOGIES Dave Johnson – Laboratory Supervisor Muskegon County

3. The Hach LDO Meter LDO = Luminescent Dissolved Oxygen

4. Measuring DO - Current Techniques  Electrode Membrane DO Meter (EPA 360.1)  Winkler Titration (EPA 360.2)

5. Winkler Titration  Interferences, positive and negative  Not a field technique  Short holding time (8 hours)

6. Electrode Membrane DO Meter  The membrane cap filled with electrolyte solution must be fitted "just right"  Membrane can become fouled  Hydrogen Sulfide gas reduces electrode sensitivity  Sample agitation (flowing water or stirring) must accompany measurement to overcome erratic responses

7. LDO Meter Theory (1 of 2)  Polymer tip permeable to oxygen.  Embedded in the polymer are molecules of luminescent dye (luminophores)  LED in the probe releases a pulse of blue light  Luminophores absorb the blue light & are energized  Return to normal energy level produces red light (fluorescence).

8. LDO Meter Theory (2 of 2)  When the blue light stops, the red fluorescence fades  If oxygen permeates into the polymer and collides with an energized luminophore, the luminophore transfers its extra energy to the oxygen molecule without fluorescing (known as “quenching”)  Quenching decreases overall fluorescence and light will fade faster than its natural decay rate.  The concentration of oxygen in the sample is inversely proportional to the length of time of the fluorescence.

9. Illustration used by permission of Dr. Cary B. Jackson of Hach Company

10. Advantages of the LDO  No more membrane caps and electrolyte solution to replace!!  No interferences  No stirring or flow necessary  No warm up time  Better precision than other techniques

11. The Good News and the Bad News...

12. The Good News  USEPA Recommends the LDO meter for NPDES compliance monitoring  The next time the list of NPDES-approved methods is updated, the LDO method will be on the list for DO and BOD.  Each USEPA region may grant blanket approval for use of the LDO method for NPDES compliance reporting

13. The Bad News  Region 5 has not given blanket approval!

14. The Bottom Line  To use the LDO meter for NPDES compliance reporting, you have to jump through the hoops of a formal Alternative Test Procedure request (ATP).

15. Region 5 ATP Request Requirements  A letter of request  Documentation of your Initial Demonstration of Laboratory Capability  A copy of your SOP  Your NPDES Permit Number (or the NPDES Permit Numbers for All Your Clients that would be affected)

16. ATP Request Requirements  Send an ATP request to: Kenneth Gunter ATP Program Coordinator USEPA Region 5 77 W. Jackson Blvd., WC-15J Chicago, IL 60604 (312) 353-9076 gunter.kenneth@epa.gov

17. Method Information  Hach Method 10360 (it was almost EPA 360.3)  ASTM D888-05, Method C  Caveat: ASTM D888-92 ≠ ASTM D888-05

18. Additional Disadvantages  Cost is $1100 - $1250, comparable to a high-end electrode membrane meter.  Hach Method 10360 has more stringent QC. Check standards must be analyzed before and after a run which ties this method more closely to the lab.

19. Preweighed Filters For Solids

20. Old vs. New

21. Advantages / Disadvantages  Advantages of pre-weighed Filters  No prep time for filters  Elimination of the large background mass of the gooch crucible  4.7 cm filters have 4 times more surface area than 2.4 cm filters (more surface area = faster filtrations)  Disadvantage  Costs approximately 3-4 times more than a 2.4 cm filter

22. Discrete Analyzers Automating Colorimetric Tests  Manufacturers  Lachat  OI Analytical  Seal Analytical  Systea Scientific  Thermo Scientific  Westco  et al.

23. Continuous Flow Analyzers (Old School)  2007: 50th Anniversary of the Invention of Continuous Flow Analyzers (1957 - The continuous flow analyzer developed by Technicon)  Problems with Continuous Flow Analyzers  Plumbing problems  High concentration samples cause carry-over  Difficult to do a color blank

24. Discrete Analyzers (New School)  Faster than continuous flow analyzers  Color blanks are no problem  The potential for carry-over is greatly reduced  Plumbing problems vanish

25. Discrete Analyzers  “Wave of the Future” for colorimetric analyses  Potential Problems/Issues  Software – you have to use what you get, not always user friendly  Purchased reagents are not always reliable  Random air bubbles can cause false positives or high bias  The high cost of consumables  Achieving acceptable detection limits  Methods can be difficult to develop  Analyzers may not analyze nitrate-nitrite by cadmium reduction. BOTTOM LINE – KNOW WHAT YOU ARE BUYING

26. Discrete Analyzers Questions to Ask your Sales Representative  What are the prices of consumables?  What are your guaranteed detection limits?  What methods can you have developed during installation before you leave?  What happens if your guarantees cannot be met?  What references can you give me? BOTTOM LINE – BE VERY THOUROUGH WHEN WRITING INSTRUMENT SPECIFICATIONS

27. Discrete Analyzers Questions to Ask Your References  Are all methods working? How long did it take to develop them?  Have any methods/analyses given you trouble?  Do you have problems with reproducibility?  Did you purchase your discrete analyzer to replace a continuous flow analyzer? Has it?  Is the software user friendly? What features do you like / dislike?  Does your instrument meet the detection limits required for your applications?  Are reagents purchased from the manufacturer reliable?  Is tech support helpful and responsive?

28. Discrete Analyzer Nitrate-Nitrite Analysis Tips  Hydrazine Reduction (SM 4500-NO 3 - H)  Approved for NPDES  Not approved for drinking water  Nitrate Reductase Method  Uses an enzyme for reducing nitrate to nitrite  Equal in performance to cadmium reduction  Method developed using Discrete Analyzers  Eliminates exposure to hydrazine sulfate and cadmium  Learn more at www.nitrate.com/nar-nam1.htm  Not approved for NPDES or Drinking Water (ATP necessary)

29. ATPs For Drinking Water  ATPs are possible for drinking water. Send these ATP requests to: Patrick Churilla Quality Assurance/Laboratory Certification USEPA Region 5 77 W. Jackson Blvd., WG-15J Chicago, IL 60604 (312) 353-6175 churilla.patrick@epa.gov

30. Digestion Blocks with Disposable Plasticware

31. Just Say No

32. Digestion Blocks Advantages / Disadvantages  Advantages  Cleaner digestions  Uniform heating  Time saved in cleaning glassware  The vessels are calibrated for volume so that aliquots can be measured directly in the vessels.  No transfer of digestates to a new vessel after digestion  Any digestion performed on a hot plate or in a water bath can be adapted for the digestion block.  Disadvantages  Initial Cost of Digestion Block ≤ $4000  Cost of consumables, approximately 35¢ - 40¢ per digestion

33. Distillation Blocks with Disposable Plasticware

34. Micro Dist ® Apparatus  Appartus Description  A heating block that can distill Total Cyanide, Ammonia, Total Sulfide, and Total Phenolics with disposable plastic- ware.  Requires only 6 ml of sample for distillation and a proportionate amount of distillation reagents.  The sample is sealed in the bottom of the tube. A trapping solution is in the upper part of the tube. A hydrophobic membrane separates the trapping solution from the sample. The Cyanide passes through the membrane and into the trapping solution.  The Cyanide passes through the membrane and into the trapping solution but the water matrix does not.  Initial Cost ≤ $4000

35. Micro Dist ® Advantages  Less reagents used. The amount of reagent to distill one sample with a regular distillation unit will do 8 samples on the MICRO DIST ®.  No purge gas flow rate to optimize each time.  Set-up time and distillation time are markedly less. (30 minute distillation for Cyanide, Ammonia, and Sulfide. Phenolics require 90 minutes.)  Able to distill 21 samples at a time.  No fragile glassware to clean up.  Very accurate and repeatable.

36. Micro Dist ® Disadvantages  The consumables are a major expense: Approximately $6 to $7 dollars per distillation tube = ~$140 in plastic consumables every time you distill a full load of 21 samples.  Samples containing organics may cause the membrane to blow out. The only recourse is to distill at a dilution (elevated detection limit).  Total CN is being replaced by available CN, which requires different instrumentation.  Limited amount of distillate means you’ll need a Discrete Analyzer or Continuous Flow Analyzer for the analysis.

37. Good News / Bad News The Micro Dist ® is approved for NPDES and Drinking Water monitoring of Total Cyanide. (QuikChem Method 10-204-00-1-X) It is NOT approved for monitoring of Total Phenolics or Ammonia

38. In Closing…  Don’t be afraid of seeking an Alternative Test Procedure (ATP)!  Don’t be afraid of trying something new (but check your references!!)  Don’t be afraid of asking for help.

39. Inductively Coupled Plasma (ICP)  Don't assume everyone's got one.  Don't assume everyone knows what one is.  Don't assume that those who have them are utilizing them to fullest.

40. ICP Overview (1 of 2)  An ICP is an Atomic Emission Spectrometer (The reverse principal of AA)  For the analysis of metals (and Phosphorus, Sulfur, Halogens)  A digested sample is nebulized (turned into a fine mist) and introduced into an argon plasma (Temperature ~10,000°C), where each metal species emits light at its own characteristic wavelengths. The intensity of the emission is proportional to the concentration of the element in the sample.  ICP has the ability to analyze for multiple elements at the same time.

41. ICP Overview (2 of 2)  Gain efficiency by transferring some analyses from your Wet Chem Section to your Metals Section  Total Phosphorus (by SW-846 6010 or 200.7) ATP Required  Hardness (by SM 2340 B)  Maintaining standards and reagents for 3 techniques vs. 1 technique

42. Analysis of Phosphorous and Hardness Advantages / Disadvantages  Advantages  Go from 2 digestions and 2 analyses to 1 digestion, 1 analysis.  Phosphorus by 200.7 has a greater linear range (fewer dilutions).  Wet Chem staff freed up for other duties.  Disadvantage  ICP does not distinguish between the different forms of phosphorus

43. ICP Hardness Analysis  Analyze the sample for Calcium and Magnesium.  Multiply the Calcium concentration by 2.497 and the Magnesium concentration by 4.118. Add them together to obtain the Hardness result.  Hardness = (2.497 x [Ca] 2+ ) + (4.118 x [Mg] 2+ )  And no ATP necessary!