1. Sampling of Nutrients in the Environment a QA/QC perspective
Dan Wruck
Supervisor, Nutrients & Environmental Waters
Queensland Health Scientific Services
Manilla, Philippines, October 2006

2. Australia
Brisbane
Sydney
Melbourne

3. Queensland Health Scientific Services
National Research Centre for Environmental Toxicology (EnTox)

4. South of the
Great Divide
Where?

5. Nutrients Lab
Leading Australian Lab - analysing approx 20,000 samples annually
Accredited to ISO/IEC 17025
Samples sourced from:
pristine freshwater
water storages
estuaries
seawater
effluent monitoring
compliance monitoring

6. Nutrients Lab Accredited Proficiency Testing Provider
Accredited to ILAC Guide 13:2000
based on ISO guide 43-1 and relevant elements of ISO/IEC 17025
Manages and Coordinates National Low Level Nutrient Collaborative Trials (NLLNCT)
More than 60 Australian & overseas labs participate
trials evaluate & provides feedback through Summary Reports, Workshops

7. Nutrients Lab Certified Reference Material Producer
Accredited to ILAC Guide 12:2000
based on ISO guide 34:1996 (quality system guidelines for the production of reference materials)
Certified Reference Materials in natural freshwaters and seawaters
Suitable for:
method development
quality control samples

8. Conductivity (µS/cm at 25oC)pH
Conductivity (µS/cm at 25oC)
Turbidity (NTU)
TSS (mg/L)
7.4
140
875
600
Hello… any crocs around???

9. Certified Values and Ranges for Dawson River

10. NLLNCT Round 9 Pristine Freshwater Site
Somerset Dam
Potable water source for Brisbane population.
Bloody good fishing spot
Conductivity
Turbidity
Total Suspended
Solids ( m
S/cm )
NTU
mg/L
300 5 6

11. NLLNCT Round 9 Pristine Seawater
Pumicestone Passage
Pristine estuary
Can be good fishing

12. Impacted seawater Prawn Farm 40,000 28 150 Conductivity Turbidity
Total Suspended
Solids ( m
S/cm )
NTU
mg/L
40,000 28
150
Prawn Farm

13. QHSS Nutrient’s Laboratory
Gary with 5 channel FIA automated analyser
Tuyet preparing samples for Kjeldahl analysis

14. Conceptual Model

15. Sampling and Analysis Design Framework (1)
Problem/Question
William Maher (1993)
Cost
Effectiveness
Objectives
Model
???????
Sampling
Indicators
Hypotheses
QUALITY QA/QC
Laboratory
Measurement
Interpretation

16. Sampling and Analysis Design Framework (2)
William Maher (1993)
Site selection
Sampling Scheme
frequency
QUALITY QA/QC
replication
Field Collection
Storage / transport
Collection Device

17. QA Requirements (1) contamination sources effecting nutrient samples
“May”
QA Requirements (1) contamination sources effecting nutrient samples
Filters
Filtration
Preservation
Digestion
Storage
Sampling
Chemistry
Contamination
Water Body
Analytical Result
Sample Containers
Hygiene

18. COMPARATIVE FINGER TEST AMMONIA
0.100
0.090
0.080
0.070
0.060
Concentration (mgN/L)
0.050
0.040
0.030
0.020
0.010
0.000 A B C D
Control
Participant

19. COMPARATIVE FINGER TEST FRP
0.000
0.005
0.010
0.015
0.020
0.025
0.030
Concentration (mgP/L)
Participant
Control A B C D

20. COMPARATIVE FINGER TEST OXN
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
Participant
Concentration (mgN/L)
Control A B C D

21. QA Requirements How to effectively monitor QA for sampling
Some Examples
Audit sample bottles before use
field blanks - take through whole sampling process
transport blank - background check
control sites
replicate samples

22. WHY DO WE COLLECT SAMPLES?
In-situ Techniques or Field Instruments
Not Robust
site access & location
equipment fouling
Quality assurance
difficult to incorporate
Inadequate detection Limits
Matrix correction

23. Monitoring Techniquesü
Key Processes –
Water quality –
Phytoplankton bioassays –
Sediment nutrient fluxes ü
Human Impacts
Sewage plume mapping
N signatures of
N signatures of mangroves ü
Critical Habitat –
Seagrass distribution and depth
range

24. PRESERVATION & STORAGE
NO universal procedure will satisfy all requirements
WHY
All water bodies contain particulate matter
the nature of the particulate matter determines how a sample behaves
Any procedure WILL require validation

25. Some factors which may effect the recovery of nutrients from a sample
Bioassimilation
Desorption from particulate
Volatilisation
Nutrient Sample
Adsorption onto container walls
Absorption by particulates
Cell destruction with freezing
Desorption from container walls
Contamination

26. Framework for Collecting Nutrient Samples
TN TKN TP
Unfiltered Sample
-18°C
HDPE containers
Water Body
NH3
NO2
NO3
TDN
TDP
0.45µm cellulose acetate
Filtered Sample

27. Sample Storage

28. Some Common Sampling Devices & Situations

29. “GRAB” - Stream
Sample into the flow
Face neck of bottle down
Invert bottle at depth of 150 mm

30. Do not disturb bottom sediments
“GRAB” - Pond
Do not disturb bottom sediments
Beaker with telescopic pole for “inspector gadget” situations

31. “GRAB” - Sample away from boat slick

32. Automatic Samplers Install in secure environment
Sampling MUST take account of preservation requirements

33. Multi-parameter ProbepH
conductivity DO
salinity
temperature

34. Van Veen
Depth Sampling
Van Dorn

35. Vacum Filtration
Metals
Chlorophyll

36. Sampling Techniques
The bucket MUST be inserted upside down and NOT inverted until below the surface of the water

37. Sampling Techniques Total Nutrients
The water sample MUST be dispensed into the container ASAP after collection to minimise the effects of sedimentation occurring

38. Sampling Techniques
The bucket MUST be inserted upside down and NOT inverted until below the surface of the water

39. Sampling Techniques Total Nutrients
The water sample MUST be dispensed into the container ASAP after collection to minimise the effects of sedimentation occurring

40. Sampling Techniques
Filtration occurs within a “closed system” minimising the risk of contamination

41. FILTRATION
???
WHY

42. Frozen
Kept on ice
Frozen
Kept on ice

46. PRESSURE - PROCEDURE ROBUST PRACTICAL SMALL VOLUMES/BOTTLES
MINIMAL CONTAMINATION
(procedure is performed in a “closed environment”)
REPRODUCIBLE
HIGH ACCEPTANCE AMONG FIELD OFFICERS
MEETS REQUIREMENTS OF AS/NZS & ISO :2003)

47. ??? FILTRATION WHY Impossible to model
Impact assessments - meaningless
Potential high costs
incorrect decisions on treatment processes
legal implications
Professional reputation

48. Sampling Scenarios - Ammonia
AS/NZS :1998
ISO :2003
Standard Methods 20th Edition
Refrigerate (6hrs)
Filter on site then acidify to pH <2 with sulfuric acid and refrigerate (21 days)
Unfiltered sample to be refrigerated (24hrs)
Filter on site and refrigerate (24 hrs)
Unfiltered sample to be acidified to pH <2 and refrigerate (1 month)
Filter on site and freeze (1 month)
Unfiltered sample to be frozen (1 month)

49. Sampling Scenarios - Nitrate
AS/NZS :1998
ISO :2003
Standard Methods 20th Edition
Refrigerate (24 hrs)
Unfiltered sample to be refrigerated (24hrs)
Unfiltered sample to be refrigerated (48hrs)
Unfiltered sample to be acidified to pH <2 and refrigerate (1 month)
Filter on site and freeze (1 month)
Unfiltered sample to be frozen (1 month)

50. Sampling Scenarios – Total Nitrogen
AS/NZS :1998
ISO :2003
Standard Methods 20th Edition
Refrigerate (24hrs)
Acidify to pH <2 with sulphuric acid (1 month)
Not discussed
Freeze (1 month)

51. Sampling Scenarios – Total Kjeldahl Nitrogen
AS/NZS :1998
ISO :2003
Standard Methods 20th Edition
Refrigerate (24hrs)
Acidify to pH <2 with sulphuric acid and refrigerate (24 hrs)
Analyse immediately
Acidify to pH <2 with sulphuric acid and refrigerate
Freeze (1 month)

52. Sampling Scenarios – Filtered Reactive Phosphorus
AS/NZS :1998
ISO :2003
Standard Methods 20th Edition
Filter on site and refrigerate (24 hrs)
Filter on site and refrigerate (1 month)
Filter on site and freeze (not specified)
Filter on site and freeze (1 month)

53. Sampling Scenarios – Total Phosphorus
AS/NZS :1998
ISO :2003
Standard Methods 20th Edition
Refrigerate (1 month)
Acidify to pH <2 with sulphuric acid and refrigerate (1 month)
Acidify to pH <2 with sulphuric acid and refrigerate (not specified)
Freeze (1 month)
Freeze (not specified)

54. Sampling Scenarios – Silica
AS/NZS :1998
ISO :2003
Standard Methods 20th Edition
Refrigerate (24 hours)
Filter on site and refrigerate (1 month)
Collect in plastic containers (not specified)
DO NOT FREEZE SAMPLES DO NOT ACIDIFY SAMPLES

55. Farmer Danny