Transcript MDEQ DRO/ORO Analysis - Michigan Water and Environment

Pete the penguin says…
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“Before the show
begins, don’t forget to
visit the snack bar”
MDEQ DRO/ORO Analysis
8015 – GC/FID
EPA 8015 and Wisconsin 8015
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These methods define Diesel Range
Organics, DRO, as anything eluting
between C10 and C28
No other carbon ranges included
An example chromatogram of diesel fuel
using C10-C28
Why change?
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This chromatogram looks OK, doesn’t it?
2000 ppm 10W30 Oil “old” method
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Much of this material is included in the C10-C28
range
Why change?
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Maybe this chromatogram doesn’t look so good,
a lot of oil is being defined as Diesel Range
Organics.
Why change?
(What are the current problems?)
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There’s still space left on the run
The diesel is gone before C28
The motor oil is half included in the diesel
range
Why change?
(What are some solutions?)
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Define DRO as C10-C20
Add Oil Range Organics as C20-C34
1000 ppm Diesel Fuel “new” method
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Most of the diesel (>90%) is contained within
the range
2000 ppm 10W30 Oil “new” method
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Much of this material would be included in the
C10-C28 range, but now has a place of its own
Why change?
(What are some outcomes)
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Better description of contaminant
There are no regulatory criteria, so its all
about aesthetics
Technical Details
Overview
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This analysis has some specific differences
from normal chromatographic analyses
Have an open mind
The quantitative results are going to be
used for guidance, not necessarily for
regulatory compliance
Technical Details
Integration/Calibration
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Baseline is drawn horizontally
All material under the signal is included
Do not integrate valley to valley
8015 allows for baseline subtraction to
account for column bleed but…
Calibration by linear regression accounts
for bleed without need for subtraction
Technical Details
Surrogate: n-Eicosane (C20)
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Why C20?
C20 is the dividing point between the two
analyte fractions
C20 is in a good range to determine
accurate extraction recovery
Easier to use area summing feature on
software (pragmatic, not lazy)
Technical Details
Surrogate: n-Eicosane (C20)
Technical Details
Surrogate Recovery
Surrogate recoveries for high
concentration samples, or samples
containing unknown or degraded
hydrocarbons should be considered
estimated.
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Technical Details
Surrogate Recovery
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A known amount of surrogate, n-eicosane, is added by
the laboratory before extraction. N-Eicosane is also
present in many petroleum products. If the product is a
known material, the presence and quantity of n-eicosane
can be accounted for. Our method includes calculations
to make corrections for surrogate recovery based on
concentrations of diesel fuel and motor oil in samples.
In samples containing unknown or degraded materials
the concentration on n-eicosane cannot be accounted
for, therefore the calculation of surrogate recovery is and
estimate.
Technical Details
Surrogate Recovery
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A known amount of surrogate, n-eicosane, is added by
the laboratory before extraction.
Technical Details
Surrogate Recovery
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N-Eicosane is also present in many petroleum products.
If the product is a known material, the presence and
quantity of n-eicosane can be accounted for.
Diesel fuel in our method has a 1.0% contribution from
C20.
10W30 Motor Oil has a 0.22% contribution from C20.
Our method has calculations to make corrections for
surrogate recovery based on concentrations of diesel fuel
and motor oil in samples.
Technical Details
Surrogate Recovery

In samples containing unknown or degraded materials
the concentration on n-eicosane cannot be accounted
for, therefore the calculation of surrogate recovery is and
estimate.
Technical Details
Surrogate Recovery

A known amount of surrogate, n-eicosane, is added by
the laboratory before extraction. N-Eicosane is also
present in many petroleum products. If the product is a
known material, the presence and quantity of n-eicosane
can be accounted for. Our method includes calculations
to make corrections for surrogate recovery based on
concentrations of diesel fuel and motor oil in samples.
In samples containing unknown or degraded materials
the concentration on n-eicosane cannot be accounted
for, therefore the calculation of surrogate recovery is and
estimate.
Technical Details
Surrogate Recovery
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If the surrogate recovery
is so estimated, why
bother to use it?
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Surrogate works OK if
sample contains diesel or
10W30 and even better
as the analyte levels
decrease. If you have no
analyte, the surrogate will
give you a good measure
of extraction recovery.
Technical Details
FID vs MSD
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Why can’t we use
GC/MS?
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You can! Just make
sure to scan to a high
enough mass to get
signal from all the
high molecular weight
compounds.
Technical Details
Disclaimer
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This method defines only the carbon
range of analytes. For example, a positive
result for DRO does not indicate diesel
fuel, only the presence of hydrocarbons in
a boiling point range similar to, or
encompassed by, diesel fuel.
Ask a question
2000 ppm 5W30 Oil “new” method
2000 ppm 20W50 Oil “new” method