Document ID: EPA-HQ-OAR-2003-0048-0235
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2005-07-20T04:00Z

From:
David
Word
[
mailto:
d_
word@
src­
ncasi.
org]
Sent:
Thursday,
April
22,
2004
2:
50
PM
To:
Katie
Hanks
Cc:
Tim
Hunt
Subject:
Method
29
Metals
Laboratory
Methods
and
Appendix
B
Katie:

I
have
been
looking
into
the
lab
methods
associated
with
metals
and
believe
I
have
a
better
handle
on
it
than
I
did
when
we
last
talked
about
this
issue.
My
understanding
is
that
a
number
of
analytical
techniques
are
used
for
metals
and
that
the
detection
limits
vary
considerably
by
method
and
to
some
extent
by
individual
metals.

Four
techniques
are
commonly
used
AA
(
AAS),
ICP
(
ICAP),
GFAA,
and
ICP­
MS
(
ICAP­
MS).
There
are
other
techniques
as
well,
such
as
ICP­
Axial,
CVAAS,
etc.

AA
is
often
referred
to
as
flame
atomic
adsorption
(
also
AAS,
atomic
adsorption
spectroscopy).
This
is
an
older
technology
that
is
used
less
frequently
as
time
progresses.
(
In
fact,
we
gave
away
our
AA
when
we
moved
to
our
new
office
about
a
year
ago,
because
the
equipment
was
considered
outdated.)
AA
has
relatively
high
detection
levels.

ICP,
iductively
coupled
plasma,
(
or
ICAP)
is
the
metals
measurement
technique
that
has
largely
replaced
AA.
My
understanding
is
that
the
detection
limits
are
generally
a
little
better
than
AA,
but
detection
limits
vary
somewhat
by
individual
metal.

GFAA
(
GFAAS)
is
graphite
furnace
atomic
adsorption.
This
method
has
significantly
greater
sensitivity
than
flame
AA.

ICP­
MS
(
or
ICAP­
MS)
is
inductively
coupled
plasma
mass
spectroscopy,
which
has
greater
sensitivity
than
'
plain'
ICP.
ICP­
MS
and
GFAA
are
both
enhancements
with
lower
detection
limits
than
ICP
and
AA.

The
above
is
mostly
based
on
conversations
with
Jeff
Louch
at
our
West
Coast
Center
and
Jim
Stainfield
in
our
Southern
Regional
Center.
But,
Method
29
also
discusses
the
various
detection
limits
in
Section
2.1
and
in
more
depth
in
Section
13.2.
In
section
13.2
Method
29
states
that
ICP­
MS
detection
limits
are
generally
lower
by
a
factor
of
10
compared
to
ICP.
The
method
does
not
provide
a
similar
statement
for
GFAA,
but
does
show
low
GFAA
(
GFAAS)
detection
limits
in
Section
13.2.4.

Table
29­
1
in
Method
29
shows
GFAAS
and
ICAP
values
­
not
AAS
and
ICAP
values.
The
values
in
parentheses
are
GFAAS
values
and
thus
are
much
lower
than
ICAP
(
ICP)
values.
(
The
footnote
was
not
written
very
well
and
is
not
real
clear.)

The
industry
as
well
as
most
laboratories
would
like
to
be
able
to
use
GFAAS
and
ICP­
MS
since
these
techniques
are
the
more
'
modern'
and
accurate
and
have
lower
detection
limits.
The
way
Appendix
B,
Section
5
(
f)(
2)
is
written,
mills
will
not
be
able
to
consider
non­
detects
as
zero
unless
AAS
is
used.
It
would
be
much
better
if
this
section
of
the
PCWP
MACT
rule
was
written
as
follows:

(
2)
For
pollutants
measured
using
Method
29
in
appendix
A
to
40
CFR
part
60,
you
analyze
samples
using
atomic
adsorption
spectroscopy
(
AAS)
or
another
laboratory
method
with
detection
limits
lower
than
or
equal
to
AAS.
This
rephrasing
of
the
rule
would
allow
mills
to
use
methods
with
lower
detection
limits
but
still
consider
non­
detects
as
zero
for
the
purposes
of
Appendix
B.

I
plan
on
calling
you
later
today
or
early
tomorrow,
but
thought
it
best
to
write
this
down
and
give
you
a
little
time
to
digest
it
before
we
talk.

Thanks
for
your
consideration.

DW
David
Word,
Ph.
D.
Program
Manager
NCASI
402
SW
140th
Terrace
Newberry,
FL
32669
(
352)
331­
1745
x241
(
Phone)
(
352)
331­
1766
(
FAX)