GAINING EFFICIENCY UTILIZING NEW ANALYTICAL TECHNOLOGIES

1
GAINING EFFICIENCY UTILIZING NEW ANALYTICAL
TECHNOLOGIES

• Dave Johnson Laboratory Supervisor Muskegon
  County

2
(No Transcript)
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
• [phone]
• gunter.kenneth_at_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-NO3- 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
• [phone]
• churilla.patrick_at_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 DisposablePlasticware
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 youll 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

• Dont be afraid of seeking an Alternative Test
  Procedure (ATP)!
• Dont be afraid of trying something new (but
  check your references!!)
• Dont 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 10,000C), 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 Ca2) (4.118 x Mg2)
• And no ATP necessary!