1. other ‘emerging tools’
Screening methods &
other ‘emerging tools’
Kees J.M. Kramer
MERMAYDE
P.O. Box 109, 1860 AC Bergen Netherlands
© Mermayde
SWIFT-WFD CMA meeting 17/11/2005
SWIFT-WFD Laboratory Training T01

2. SWIFT – WFD Project Objectives: inventory of existing methods
production of QC tools for validating methods
comparison of biological and chemical methods
comparison of laboratory and field methods
evaluate cost effectiveness
provide training
link (new) monitoring science to policy
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3. Monitoring objectives
WFD
Ecosystem health
geographic distribution
temporal change
Early warning
spills, discharges,
accidents
Public health
drinking water
bathing water
food
Monitoring types:
investigative
surveillance
operational
Approaches
ecological status
chemical status
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4. ‘Traditional’ only? Focus on priority pollutants Proven techniques
Qualification and quantification
Validated
Standard methods
new developments?
systematic bias?
‘Other’ or future compounds
‘Other’ monitoring techniques
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5. Screening methods Strategy
screens for ‘groups’ rather than specific compound
PAHs vs benzo[a]pyrene
triazine pesticides vs atrazine
trace metals vs cadmium
relatively simple method
use may be by medium level staff
fast
cheap
possibly field operation
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6. Screening methods Strategy integrated ‘signal’ may be semi-qualitative
may be semi-quantitative
when ‘group’ < threshold level, ‘all’ are
when ‘group > threshold level
>> further detail needed using techniques that allow quantification and qualification
‘alarm’ may induce spot sampling
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7. ‘Traditional’ vs ‘Test-kit’
concentration
threshold value
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8. ‘Traditional’ vs ‘Screening’
screening method
‘signal‘
threshold value
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9. Representative sampling
More representative picture of water quality can be obtained using a number of approaches:
frequent sampling
automatic sequential sampling to provide composite samples over a period of time (usually 24 hours)
continuous, on-line monitoring systems (e.g. some sensors, SAMOS system)
biomonitoring, biological early warning
passive samplers (organic, inorganic)
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10. Sampling strategies integrated sampling on line monitoring
© Mermayde
spot sampling
SWIFT-WFD Laboratory Training T01

11. TWA time weighted average
‘Passive’ sampling
TWA time weighted average
time
contaminant concentration
in a single sample
diuron
concentration
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12. ‘Screening methods’ Better: ‘Emerging tools’ Examples:
integrated sampling (‘passive samplers’, biota)
(bio)sensors
immuno assays
test-kits
biomarkers
bioassays
biological early warning systems (BEWS) …
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13. ‘Emerging tools’ may offer:
New technologies (sensors, …)
Wider view than priority pollutants only (“what you are not looking for, you don’t find!”)
24/24 h, 7/7 days
‘Screening’, when signal passes criteria, investigate by detailing techniques
Efficient, low cost
Answer to different monitoring ‘needs’
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14. Trends in ‘emerging tools’ 1
‘Traditional’ methods:
Chemical analysis of spot samples & use of some (on line) sensors
(usually) low sampling frequency
identification and quantification of compounds
criteria easy to define
validation and intercomparison relatively easy
focus on priority pollutants impossible to measure all compounds
© Mermayde
SWIFT-WFD Laboratory Training T01

15. Trends in ‘emerging tools’ 2
Chemical analysis of biota (‘mussel watch’), and use of ‘Passive Samplers’
time integrated sampling
increased concentrations, easier/better analysis
identification and semi-quantification of compounds
quantification relies on assumptions about relation water  ‘sampler’ (accumulation)
criteria less easy to define
validation and intercomparison less easy
focus on priority pollutants impossible to measure all compounds
© Mermayde
SWIFT-WFD Laboratory Training T01

16. Trends in ‘emerging tools’ 3
Screening methods (give info on group of compounds)
quantification based on summed signal
semi-identification and semi-quantification of compounds
(semi) continuous operation
criteria less easy to define
validation and intercomparison less easy
© Mermayde
SWIFT-WFD Laboratory Training T01

17. Trends in ‘emerging tools’ 4
Biological effect methods (tox-tests, biological early warning systems)
signal is summed biological response to ‘all’ compounds
non-identification and semi-quantification of pollutants
(semi) continuous operation
criteria compound non-specific
validation and intercomparison less easy
© Mermayde
SWIFT-WFD Laboratory Training T01

18. Identification & quantification
Chemical and biological screening methods
quantification identification
‘traditional’ analysis
analyte specific (bio)sensors + +
‘test kits’ +/- +
‘analyte group’ screening
‘analyte group’ (bio)sensors
general parameters (e.g. TOC) +/- -
biological effects (tox-tests) +/- -
biological early warning +/- -
© Mermayde
SWIFT-WFD Laboratory Training T01

19. Framework for reliable results
Analytical measurements should be made to satisfy agreed requirements as set in the WFD
using tested methods and equipment
by qualified and competent staff
be consistent with analysis made elsewhere
by Labs with well defined QA/QC procedures
be subject to regular and independent assessment of the performance
© Mermayde
SWIFT-WFD Laboratory Training T01

20. QA/QC in ‘emerging tools’?
Yes, of course
methods shall be validated, but
may be not be calibrated to the compound
different, adapted validation approaches
QA shall be installed, QC where possible
staff shall be capable
criteria shall be defined
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SWIFT-WFD Laboratory Training T01

21. Results may give different (types of) answers e.g.
Conclusion
Results may give different (types of) answers e.g.
[PAHs] < 2 g/L
‘signal >100’
‘alarm!’
Shall link to policy questions
Maximum information at minimum cost
Supplement ‘traditional’ monitoring methods
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22. Keep open mind for new technologies
Final message
‘Emerging tools’ shall not a priori be excluded from ‘accepted’ monitoring methods
Keep open mind for new technologies
Guidelines shall allow incorporation of new (future) methods
Methods shall be validated
Results shall be ‘Fit-for-purpose’
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