Transcript Sample Collection and Preservation

Sample Collection and
Preservation
Importance
 Safety
 Quantities
 Sampling utensils
 Sample Types
 Collection Methods
 Preservation
 Storage
 Hold times
 COCs
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Why we sample
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To verify compliance for NPDES
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To determine if our processes are efficient
Some Basics
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Must be representative
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Consider your collection point
Consider the analysis
Sample containers must be clean and free
from interference
Must be handled right to avoid
degradation, contamination, compromising
Correct collection and preservation
Low level mercury
 Biological
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Safety
Safety
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Assess the potential for hazards
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Physical
leaning, stretching, pulling, lifting
 Awkward positions
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Constituents
Toxic, biological, pathogens
 Entry: skin, eyes, nose, mouth
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Safety
General PPE
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Gloves
Eye protection
Ventilate area if vapors may be present
Specific PPE
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Containment suits
Special gloves, boots
Sampling utensils
Collection
Storage
Collection Containers
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Manual
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Dippers
Buckets
Automated
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Flow based
Time based
Manual
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Grab samples or composite grab
Mix well before transfer
Proper container
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Rusty coffee cans are probably not the right
container…….
Automated
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Usually 24 hour
Flow based more accurate than time
based
Clean tubing
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2 sets- one cleaning, one in use
Wear on tubing could change volume
pumped
Calibrate pump frequently
NPDES states to pull at least 100ml
Collection Containers
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Dedicate containers
Clean containers well
Use detergents that are free of
interference/contamination potential
Rinse with DI water 3 X
Dry completely
Container should not interfere with analysis
A word about “C”
Organic Carbons
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Can not use plastic containers to collect
VOC, TOC, or any C’s
It will contaminate sample
Storage Bottles
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Glass or plastic
Hard glass (pyrex) is preferred
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Silica, sodium, and boron may be leached
from soft glass but not plastic
Use glass for all organics (VOC, semi VOC,
pesticides, PCBs, oil and grease)
Avoid plastic when possible- phthalate esters
can contaminate sample
Storage Bottles
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Use amber glass bottles to avoid
photodegradation
Caps are important too!
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No paper liners
Use foil or PTFE liners
Be aware that metal liners can contaminate
samples for metals
Quantities
How Much do you need
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Most methods tell you the minimum
quantity needed
Give yourself some extra
For pre-preserved containers
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Make sure that the quantity collected is the
right volume. Don’t fill ¼ full if the bottle
needs to be full.
Sample Types
Grab Sample
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Provide “snapshot”
Used for process control
Short hold time
Used when samples are not variable
Used for testing that requires immediate analysis
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Cl2, pH, temp, organic, volatiles
Several grabs over time course to show
variability
Composite Sample
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Represent heterogeneous matrix
Can be set to represent flow based
Can result in loss or dilution of analyte
Can result in increase interferences
Can not be used on certain tests
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Cl2, pH, temp
Control Samples
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Field blank
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Lab blank
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Usually DH20 transferred from one container to
another while at sampling site
Usually low level contaminates
Usually DH2O analyzed in tandem
Tests for contamination/proper technique
Indicates background levels
Collection Methods
How to collect - Grab
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Pole dippers
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Buckets
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Secure container
Submerge container
Start downstream and move into flow
Direct
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Start downstream and move into flow
How to collect - Composite
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Set Sampler to collect flow based or timed
Determine potential for contamination
from tubing
Tubing should be clean
Tubing should be located in area that is
representative
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Don’t rest on bottom
Avoid dead areas
Needs to be in center of flow
How to collect
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Same location every time
TOC and some volatiles should not be put
into plastic containers
Transfer quickly with minimal exposure to
air
Don’t transfer multiply times
Cap container quickly
Label the container
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Time, date, location, collector
Composite
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Collection bottle should be refrigerated
Clean tubing and collection bottle
Collection bottle should be large enough
to mix sample
Mix the right way
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Too little and not enough mix of settlables
Too much and incorporate air/analyte loss
Receiving Waters
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For stream sampling, make sure you enter
downstream of where you will take sample
Move upstream to gather your samples if
you have multiple sites
Change gloves frequently
Filling bottles
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Minimize exposure to air when transferring
Don’t overfill pre-preserved bottles
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Put preserve in bottle after sample
Leave headroom for biologicals
No air bubbles for volatiles
What do you do with those caps?
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Handle caps with care
Setting them on the ground risks
contamination
Setting them upright risks contamination
Holding them risks contamination
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Depends on the surroundings……
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Low Level Mercury
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Two people
Dirty hands/clean hands
technique
One person only handles
the sample containers
One person collects
sample, pours into
sample container
Composite Grabs
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NPDES states “at least” 8 grabs of at least
100 mls over periodic intervals during
working hours
Collect each grab and refrigerate
Mix equal amounts of grabs together
Mix well
Example: radium in sludge
Soapbox Time
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Wear gloves
Protects you
Protects the sample
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DEET
Lotions/soap
Do you know where your hands have been?
Preservation
Preservation Limited to:
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pH control
Chemical addition
Amber or opaque bottles
Refrigeration
Filtration
Freezing
Why Preserve
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Retard biological action
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Retard hydrolysis of chemical compounds
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Reduce volatility of analyte
Preservation
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Depends on Analysis
Some acids can degrade plastics- be
careful
Storage
Storage
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Ice or refrigerate immediately
Keep temperature from fluctuating
Preserve immediately if bottle is not prepreserved
Some samples are stored at room temp
Hold times
Hold times
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Begins when sample is collected
Depends on analyte
Rule of thumb:
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The quicker it’s analyzed, the better
COCs
Many Faces of COCs
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Labels
Seals for bottles
Facility bench sheets/ Field log books
Analysis request sheet (COC)
Record of delivery to laboratory
Receipt and logging of sample
Assignment of sample
Chain of Custody
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Traceability
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Shows who handled sample from collection,
preservation, storage, and analysis.
Allows for routine control of samples and
also aides in litigation issues
Labels
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Permanent maker
Attached to container
Lists the following:
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Date and time of collection
Facility
Location
Type of sample
Preservative
Analysis
Collector
COC
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Usually from Lab
Fill out completely
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Sample name, date and time of sample
Type of sample
Preservative
Bottle and volume
Analysis needed
NPDES permit fine print
(10) Monitoring and records.
(a) Samples and measurements taken for the purpose of monitoring shall be representative of the
monitored activity.
(b) The permittee shall retain records of all monitoring information, including all calibration and
maintenance records, and all original strip chart recordings for continuous monitoring
instrumentation, copies of all reports required by this permit, and records of all data used to
complete the application for this permit, for a period of at least 3 years from the date of this
permit, measurement, report or application. This period may be extended by request of the
Agency at any time.
(c) Records of monitoring information shall include:
1.
2.
3.
4.
5.
6.
The
The
The
The
The
The
date, exact place, and time of the sampling or measurements;
individual(s) who performed the sampling or measurements;
date(s) analysis were performed;
individual(s) who performed the analyses;
analytical techniques or methods used; and
results of such analyses.
(d) Monitoring must be conducted according to test procedures approved under 40 CFR Part 136,
unless other test procedures have been specified in this permit. Where no test procedure under
40 CFR Part 136 has been approved, the permittee must submit to the Agency a test method for
approval. The permittee shall calibrate and perform maintenance procedures on all monitoring
and analytical instrumentation at intervals to ensure accuracy of measurements.
NPDES Requirements
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All calibration and maintenance Records
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Yearly maintenance of balance etc
Replacement date of probes
Thermometer calibrations
Pipettes
Original strip chart recordings
Required Reports
Keep for 3 years
Bench Sheets
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Date, exact location, collector and time of
sample
Date, time, analyst, and method for each
test
Record results in proper units
Include time points for analysis
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time in /time out of oven, weighing, ect
Daily temperatures and calibration of
instruments need to be recorded
Rumors
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EPA, IEPA are taking a closer look at
paperwork.
Make sure you have it written down
Make sure you have a copy
If you don’t have SOPs, make sure you
can at least support your procedure
Resources
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CFR has hold times and preservatives
Standard Methods 1-33 has hold times,
preservatives and container types and size
NPDES
EPA/ IEPA
FVOA
Don’t worry so much…..
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“Complete and unequivocal preservation
of samples, whether domestic wastewater,
industrial wastes, or natural waters, is a
practical impossibility because complete
stability for every constituent never can be
achieved. At best, preservation techniques
only retard chemical and biological
changes that inevitably continue after
sample collection”
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Doesn’t mean we shouldn’t try.
Just need to be realistic
Follow basic rules
Be consistent
Analyze as soon as possible