United States
Environmental Protection
Agency
Industrial Environmental
Research Laboratory
Research Triangle Park NC 2771
Research and Development
EPA-600/S7-84-060 Aug. 1984
Project Summary
Feasibility of Using Solid
Adsorbents for Dioxin Sampling
F.L DeRoos and A.K. Wensky
Recovery efficiencies from XAD-2
resin (Amberlite) and Horisil of spiked
2,3,7,8-tetrachlorodibenzo-p-dioxin (2.
3,7,8-TCDD) were determined to
assess the suitability of these adsorb-
ents for sampling. Two spiking methods
were used: Method A consisted of
uniformly depositing 1 ml of the
spiking solution onto the adsorbent,
and Method B consisted of covering
the whole adsorbent sample with the
spiking solution. There was no signifi-
cant difference in recovery efficiencies
between the two methods or between
the two adsorbents. The overall recovery
from XAD-2 resin was 92 ± 8%, and 95
± 6% from Florisil.
This Project Summary was developed
by EPA's Industrial Environmental
Research Laboratory, Research Triangle
Park, NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering
information at back).
Introduction
Due to the well known toxicity and ubi-
quitous nature of polychlorinated diben-
zo-p-dioxins (PCDDs) in industrial manu-
facturing streams and (in particular)com-
bustion sources, EPA initiated this pro-
gram as part of a general effort to demon-
strate the reliability of the sampling and
analysis procedures. The specific goal of
this program is to assess the extraction
efficiency of 2,3,7,8-tetrachlorodibenzo-
p-dioxin (2,3,7,8-TCDD) (chosen to repre-
sent this group of compounds) from XAD-
2 resin or Florisil. These adsorbents are
normally used in collecting organics
emitted from combustion sources in
either the source assessment sampling
system (SASS) train or the Modified
Method 5 (MM5).
Experimental Procedures
The spiking of 2,3,7,8-TCDD into XAD-
2 and Florisil was carried out using two
methods:
Method A consisted of uniformly
depositing 1 ml of methylene chloride
containing either 3 ng or 30 ng of 2,3,7,8-
TCDD onto the surface of a 15 g portion of
the adsorbent (XAD-2 or Florisil).
Method B consisted of depositing
approximately 25 mL of the methylene
chloride spiking solution containing
either 3 ng or 30 ng of 2,3,7,8-TCDD to
cover the whole body of the adsorbent.
In both cases, methylene chloride was
removed by evaporation at room temper-
ature.
Sample Extraction and
Cleanup
The spiked samples were Soxlet-
extracted for 16 hours with 250 mL of
methylene chloride. The methylene
chloride extract was spiked with 2 ng of
2,3,7,8-TCDD-13C12 to serve as an
internal standard to quantify the native
2,3,7,8-TCDD and to correct for any losses
during experimental workup. The extracts
were concentrated to approximately 1 mL
using the Kuderna-Danish (K-D) appara-
tus.
The extracts were cleaned up using two
chromatography columns. The first
column was a multilayered silica column
containing alternate layers of activated
silica, 44% concentrated sulf uric acid on
silica, and 33% 1M potassium hydroxide
on silica in order to temper acidic and
basic compounds as well as easily
oxidized materials that might have been
co-extracted along with the 2,3,7,8-
TCDD. A hexane/benzene (1:1) mixture
was used as the eluent. The eluate was
concentrated using K-D and solvent-
exchanged into 1 -2 mL of hexane prior to
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adding it to the second chromatographic
column containing approximately 5 g of
activated basic alumina. The column was
eluted sequentially with hexane, hexane/
carbon tetrachloride and hexane/methyl-
lene chloride. 2,3,7,8-TCDD collected in
the hexane/methylene chloride eluate
was stored at O°C after solvent-exchang-
ing into n-decane.
Instrumental Analysis
High resolution gas chromatography/
high resolution mass spectrometry
(HRGC/HRMS) was used to quantify the
2,3,7,8-TCDD. The HRMS system was a
VG Model MM-7070H in conjunction
with a VG Model 2035 data system.
Results
Results of the 28 spiking experiments
are summarized in Table 1 for XAD-2
resin, and Table 2 for Florisil. The 2.1 ng
and 16.5 ng levels were the actual
determined levels in the spiking solution
targeted at 3 ng and 30 ng, respectively. A
possible explanation for the determined
levels is loss of the 2,3,7,8-TCDD due to
degradation during long storage periods.
The data show no significant difference in
spike recoveries based on the spiking
method: solution deposited on the
adsorbent (Method A), or solution cover-
ing the whole adsorbent sample (Method
B). The average recovery of spiked
2,3,7,8-TCDD from XAD-2 was 94 ± 6%
when Method A was used, and 91 ±10%
when Method B was used. The average
recovery from Florisil was 102 ± 6%
when Method A was used, and 89 ± 6%
when Method B was used.
Overall recovery from XAD-2 is 92 ±
8%, and 95 ± 6% from Florisil.
Table 1. Recovery Data for Spiked Native 2.3,7.8-TCDD on XAD-2 Resin
Native
Spike Level
(ng)
0
2.1
16.5
0
2.1
16.5
naiivi
Rep. 1
0.08
2.0
17.4
0.010
1.8
14.2
e ueiermmea i
(ng)
Rep. 2
ND*
1.8
16.3
ND
1.8
14.3
.evei
Recovery Percent
Rep. 3
ND
1.7
15.6
ND
2.2
16.O
Rep. 1
ND
95
105
ND
86
86
Rep. 2
ND
86
99
ND
86
87
Rep. 3
ND
81
95
ND
105
97
Avg.
ND
87
100
ND
92
90
92C
RSD*
(%)
ND
8
5
ND
12
7
8°
Spiking
Method
A
A
A
B
B
B
'RSD = Relative standard deviation.
b/V0 = Not determined.
^Overall recovery.
Table 2. Recovery Data for Spiked Native 2,3,7.8-TCDD on Florisil
Natjve Native Determined Level
Spike Level
(ng)
0
2.1
16.5
0
2.1
16.5
Rep. 1
0.017
2.2
17.9
0.034
1.7
16.8
(ng)
Rep. 2
ND"
2.0
17.8
ND
1.7
14.9
Recovery Percent
Rep. 3
ND
1.8
18.O
ND
1.9
15.O
Rep. 1
ND
105
108
ND
81
102
Rep. 2
ND
95
108
ND
81
90
Rep. 3
ND
86
109
ND
90
91
Avg.
ND
95
108
ND
84
94
95°
RSD*
!%)
ND
11
1
ND
6
7
6"
Spiking
Method
A
A
A
B
B
B
*RSD = Relative standard deviation
*ND - Not determined
C0verall recovery
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F. L DeRoos and A. K. Wensky are with Battel/e-Columbus Laboratories,
Columbus, OH 43201.
Merrill D. Jackson is the EPA Project Officer (see below).
The complete report, entitled "Feasibility of Using Solid Adsorbents for Dioxin
Sampling," (Order No. PB 84-215 482; Cost: $7.00, subject to change) will be
available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
U.S. GOVERNMENT PRINTING OFFICE; 1984 - 759-015/7774
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
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