United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
Las Vegas, NV 89193-3478
Research and Development
EPA/600/S4-89/049 May 1990
^rfil^^
JUP
&EPA Project Summary
Evaluation of Sample Extract
Cleanup Using Solid-Phase
Extraction Cartridges
Viorica Lopez-Avila, Janet Benedicto, June Milanes and Werner F. Beckett
Fractionation and cleanup of
sample extracts prior to instrumental
analysis is used to remove
coextracted materials that interfere
with the determination of target
analytes. Such fractlonations and
cleanups are usually accomplished
by column chromatography, gel
permeation chromatography, or acid-
base partitioning. The purpose of this
project was to evaluate the
application of solid-phase extraction
cartridges containing Florisil,
alumina, silica, and diol to the
fractionation and cleanup of sample
extracts containing organochlorine
pesticides and polychlorinated
biphenyls listed in SW-846 Methods
8080/8081, phthalate esters listed in
Method 8061, and phenolic
compounds listed in Method 8040.
Cartridge loading and the effects of
matrix interferents such as those
present in corn oil and diesel
hydrocarbons, and elemental sulfur
were investigated. Such interferents
were selected because they mimic
typical background contamination in
the presence of which the target
compounds may need to be
determined. In addition to these
synthetic matrices, several extracts
of environmental samples were
spiked with the target analytes at
known concentrations and were then
fractionated using the solid-phase
extraction procedures. A draft
protocol for the use of solid-phase
extraction cartridges was prepared
and was tested with spiked synthetic
matrices and spiked extracts of real
samples.
The results of this study indicate
that the use of solid-phase extraction
cartridges for the cleanup of sample
extracts is feasible for a variety of
matrices and target compounds. The
use of cartridges simplifies the
cleanup procedure, especially when
automated (robotic) systems are
used, reduces solvent and adsorbent
usage and decreases labor cost in
sample preparation. Also included in
this report as an appendix is a
literature review covering the state-
of-the-art technology on the solid-
phase extraction cartridges and their
use in extract cleanup/fractionation.
This Project Summary was
developed by EPA's Environmental
Monitoring Systems Laboratory, Las
Vegas, NV, to announce key findings
of the research project that is fully
documented in a separate report of
the same title (see Project Report
ordering information at back).
Introduction
Fractionation or cleanup of sample
extracts prior to instrumental analysis for
organic compounds (e.g., gas
chromatography) is used to remove
coextracted materials that interfere with
the determination of target analytes. Such
fractionations are usually accomplished
by column chromatography (e.g., on
Florisil, alumina, silica gel), gel
permeation, chromatography, or acid-
base partitioning. More elaborate
fractionation schemes that involve a
combination of such cleanup procedures
can be quite tedious, and experienced
analysts are required for their successful
application.
Standardized cleanup procedures such
as Methods 3610 and 3620, published in
the Office of Solid Waste Manual SW-
846, revised recently (1), specify
amounts of alumina and Florisil in excess
of 10 g and large volumes of eluting
solvents. For example, a 10-g Florisil
column and 100 mL of 20 percent diethyl
-------
ether in hexane are recommended for
cleanup of sample extracts containing
phthalate esters. Such large volumes of
solvents increase the likelihood of sample
contamination by impurities present in
solvents. Furthermore, the adsorbent
materials and the solvents are not
recycled, and although such materials are
not overly expensive, the time required
for the preparation of the adsorbent, for
the packing of the chromatographic
columns, for the elution of the target
analytes from the columns, and for the
evaporation of solvents contributes to the
overall cost of analysis.
The purpose of this study was to
evaluate the application of solid-phase
extraction (SPE) cartridges containing
Florisil, alumina, silica, and diol to the
fractionation/cleanup of sample extracts
containing organochlorine pesticides and
polychlorinated biphenyls listed in SW-
846 Methods 8080/8081, phthalate esters
listed in Method 8060, and phenolic
compounds listed in Method 8040.
Cartridge loading and the effects of
matrix interferents such as those present
in corn oil and diesel hydrocarbons, and
elemental sulfur were investigated. Such
interferents were selected because they
mimic typical background contamination
in the presence of which the target
compounds may have to be determined.
For example, corn oil is representative of
the fatty acid triglycerides, and diesel
hydrocarbons are representative of
petroleum hydrocarbons. Elemental sulfur
was chosen because this compound is
extracted from soils, or sediments along
with target analytes and interferes with
their gas chromatographic determination,
especially when an electron capture
detector is used for compound
identification and quantification. In
addition to these synthetic matrices, sev-
eral extracts of environmental samples
were spiked with the target analytes at
known concentrations and were
fractionated using the solid-phase
extraction cartridge procedure.
Experimental
Cartridge Cleanup Procedure
Florisil, alumina, and silica cartridges
were conditioned prior to use with 4 mL
hexane. Diol cartridges were conditioned
with hexane with 10 percent acetone.
Aliquots of 2 ml of standards or sample
extracts in hexane were loaded onto SPE
cartridges using a micropipette and were
eluted with the solvents indicated in the
tables summarizing the data. A
Supelclean Visiprep vacuum manifold
(Supelco, Inc.) and a VacElute SPS24
(Analytichem International) were used to
simultaneously prepare as many as 12
samples (for the Visiprep system) or 24
samples (for the VacElute SPS24
system). When using the Visiprep
system, the vacuum for each cartridge
was adjusted manually using chemically
inert screw-type valves. Details of the
cartridge cleanup procedure can be
found in the protocol included in
Appendix B of the full report.
Gas Chromatographic Analysis
All fractions were analyzed by gas
chromatography with ECD using the dual-
column approach.
The GC operating conditions for the
organochlorine pesticides were as
follows: 30-m x 0.53-mm ID DB-608
(0.83-nm film) and 30-m x 0.53-mm ID
DB-1701 (1.0-nm film) connected to an 8-
in injection tee (Supelco, Inc.).
Temperature program: 150°C (0.5-min
hold) to 275°C (15-min hold) at 5°C;
injector temperature 250 °C; detector
temperature 320°C; helium carrier gas 6
mL/min; nitrogen makeup gas 20 mL/min.
GC operating conditions for the
phthalate esters were as follows: 30-m x
0.53-mm ID DB-608 (0.83-iim film) and
30-m x 0.53-m ID DB-1701 (1.0-iim film)
connected to an 8-inch injection tee
(Supelco, Inc.). Temperature program:
250°C (5 mm hold) to 275°C (15 min
hold) at 5°C/min; injector temperature
250°C; detector temperature 320°C;
helium carrier gas 6 mL/min; nitrogen
makeup gas 20 mL/min.
GC operating conditions for the
phenols were as follows: 30-mm ID DB-5
(0.83-yim film) and 30-m x 0.53-mm ID
DB-1701 (1.0-nm film) connected to an 8-
inch injection tee (Supelco, Inc.).
Temperature program: 150°C (5 min
hold) to 275°C (15 min hold) at 5°C/min;
injector temperature 250°C; detector
temperature 320°C; helium carrier gas 6
mL/min; nitrogen makeup gas 20 mL/min.
Phenols were derivatized with
pentafluorobenzyl bromide (PFBBr)
following the procedure by Lee et al. (2).
Results and Discussion
Organochlorine Pesticides and
Polychlorinated Biphenyls
The current SW-846 Methods
8080/8081 for organochlorine pesticides
and polychlorinated biphenyls (PCBs)
determination recommend use of either
Florisil (Method 3620) or silica gel for
cleanup of sample extracts containing
organochlorine pesticides and PCBs. We
evaluated Method 3620 and found that,
although compound recoveries v
quantitative, the Florisil fractions
method is not suitable for samples
contain both organochlorine pestic
and PCBs (3) since the PCBs are el
in the same fraction as the bulk of
organochlorine pesticides. We under
the evaluation of Florisil cartrid
specifically for samples that contain
the organochlorine pesticides. The s
cartridges were considered since Me
8081 describes a procedure in w
PCBs can be separated from the bul
the organochlorine pesticides using s
gel deactivated with 3 percent w;
Finally, diol cartridges were evalui
since at the time our study '
conducted, EPA was considering the
of diol cartridges for incorporation
the Contract Laboratory Progi
protocols.
The results of the evaluation study
summarized below:
• The use of silica cartridges provei
be superior to the use of Flo
cartridges because it allov
complete separation of the PCBs f
all but four organochlorine pesticii
quantitative recovery of
compounds, and almost comp
separation of the Method 81
organochlorine pesticides from
Method 8060 phthalate esters.
separate the PCBs, the 1-g si
cartridges required elution with 3
hexane. To recover quantitatively
organochlorine pesticides, the si
cartridges were further eluted wit
mL hexane with 50 percent die
ether (Table 1).
• The use of diol cartridges also alii
separation of the PCBs from
organochlorine pesticides when
cartridges are first eluted with hexj
and quantitative recoveries for
organochlorine pesticides
achieved when the cartridges
eluted with hexane with 10 perc
acetone (Table 2).
• The procedure that uses sil
cartridges and hexane with 50 perc
diethyl ether was tested w
cartridges of 0.5-g, 1-g, and 2-g s
each charged with 17 organochloi
pesticides at 0.2 ng, 1.0 ng, and 2.G
per cartridge. Two fractions w
collected from the 0.5-g and
cartridges. An additional 5 mL
hexane with 50 percent diethyl el
were passed through the 2j
cartridges to collect Fraction 3.
compounds, except endrin aldehy
were recovered quantitativ
(recovery >75 percent) in the twc
three fractions combined. The elu
-------
Table 1. Percent Recoveries and Button Patterns for 17 Organochlorine Pesticides from 1-G Silica
Cartridges'
Fraction 1 Fraction 2
Compound
alpha-BHC
gamma-BHC
beta-BHC
Heptachlor
delta-BHC
Aldrin
Heptachlor epoxide
Endosulfan 1
4,4'-DDE
Dieldrin
Endrin
4,4'-DDD
Endosulfan II
4,4'-DDT
Endrin aldehyde
Endosulfan sulfate
4,4'-Methoxychlor
Aroclor 1016
Aroclor 1221
Aroclor 1232
Aroclor 1242
Aroclor 1248
Aroclor 1254
Aroclor 1264
Average
recovery
0
0
0
97.3
0
95.9
0
0
99.9
0
0
10.7
0
94.1
0
0
0
124
93.5
118
116
114
108
112
Percent Average
RSD recovery
98.7
94.8
94.3
1.3 0
90.8
1.0 0
97.9
102
1.7 0
92.3
117
41 92.4
96.0
2.0 0
59.7
97.8
98.0
Percent
RSD
2.3
1.9
3.0
2.5
2.1
2,3
2.0
2.6
3.3
2.2
2.6
2.1
2.4
• Silica cartridges (Supelco, Inc. lot SP0161) were used; each cartridge was conditioned with 4 mL hexane
prior to use. The organochlonne pesticides were tested separately from PCBs. For organochlorine
pesticides, each experiment was performed in duplicate at three spiking levels (0.2 itg, 1.0 itg, and 2.0 [tg
per compound per cartridge). Fraction 1 was eluted with 5 mL hexane, Fraction 2 with 5 mL hexane with 50
percent diethyl ether. PCBs were spiked at 10 itg per cartridge and were eluted with 3 mL hexane. The
values given for PCBs are the percent recoveries for single determinations.
patterns seem to vary with the size of
the cartridge; however, they are very
consistent within one cartridge size.
For example, in the case of the 0.5-g
cartridges, 7 compounds, namely
alpha-BHC, gamma-BHC, heptachlor,
aldrin, 4,4'-DDE, 4,4'-DDD, and 4,4'-
DDT, were recovered in Fraction 1,
and 13 compounds were recovered in
Fraction 2, demonstrating that some
compounds are present in both
fractions. The number of compounds
recovered in Fraction 1 from the 2-g
cartridges decreased to three
(heptachlor, aldrin, and 4,4'-DDE), and
an additional 5 ml of hexane with 50
percent diethyl ether were needed to
recover delta-BHC, endosulfan II,
endrin aldehyde, and endosulfan
sulfate from the 2-g silica cartridges.
The procedure that uses diol
cartridges and hexane with 10 percent
acetone was tested with 0.5-g, 1-g,
and 2-g size cartridges. Each cartridge
was charged with 17 organochlorine
pesticides at 0.2 ng, 1.0 pg, and 2.0
ng. Two fractions were collected from
the 0.5-g and 1-g cartridges, and up to
four fractions were collected from the
2-g cartridges. Overall, all compounds
were recovered quantitatively
(recovery >75 percent) in the two,
three, or four fractions combined. At
the 0.2-ng spike level, sixteen
compounds were eluted in Fraction 1
from the 0.5-g cartridges, and only two
compounds (endrin aldehyde and
endosulfan sulfate) were eluted in
Fraction 2. Small amounts (<6
percent) of delta-BHC and endosulfan
II were found in Fraction 2 from the
cartridges spiked at 2.0 ug per
cartridge. As the cartridge size
increased, more compounds were
found in Fraction 2. For example, in
addition to delta-BHC and endosulfan
II, endrin aldehyde and endosulfan
sulfate were detected in Fraction 2
from the 1-g cartridges spiked at 0.5
ng and 2.0 ng per cartridge. In
addition, beta-BHC and small amounts
of gamma-BHC and 4,4'-
methoxychlor were detected in
Fraction 2 from the 1-g cartridges
spiked with 2.0 ng. Finally, the elution
patterns for the 2-g cartridges were
quite different from those of the 0.5-g
and 1-g cartridges, and they also
varied with the amounts spiked on the
cartridges.
Corn oil or diesel hydrocarbons did
not affect the elution patterns of the 17
organochlorine pesticides from either
the silica or the diol cartridges (Tables
3 and 4). Elemental sulfur, if present,
is eluted from the silica cartridge with
5 mL hexane and will interfere only
with the gas chromatographic analysis
of heptachlor and aldrin on the DB-
1701 column. 4,4'-DDE and 4,4'-DDT
also elute in Fraction 1, however, they
can be quantified without any difficulty
-------
Table 2. Elution Patterns and Percent Recoveries of 17 Organochlorine Pesticides and Aroclor 1260 from 1-g Diol Cartridges
Spiked with organochlorine pesticides at 0.2 ng and Spiked with Organochlorine pesticides at 0.2 {ig and
Aroclor 1260 at 80 iig per cartridge Arochlor 1260 at 2 yg per cartridge
Compound
Aroclor 1260
alpha-BHC
gamma -SHC
beta-BHC
Heptachlor
delta-BHC
Aldrin
Heptachlor epoxide
Endosulfan I
4,4 '-DDE
Dieldrin
Endrin
4,4' -ODD
Endosulfan II
4,4'-DDT
Endrin aldehyde
Endosulfan sulfate
4,4'-Methoxychlor
Fraction 1
(3 mL hexane)
90
0
0
0
112
0
116
0
58.5
124
0
0
0
0
>100a
0
0
0
Fraction 2
(5 mL hexane
with 10 percent
acetone)
10
93
105
103
0
97.3
0
97.3
71.5
0
108
>100a
99.5
>700«
0
39.5
29.2
>700a
Fraction 3
(5 mL hexane
with 10 percent
acetone)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
60.5
70.8
0
Fraction 1
(3 mL hexane)
100
0
0
0
102
0
110
0
59.2
123
0
0
0
0
100
0
0
0
Fraction 2
(5 mL hexane
with 10 percent
acetone)
0
106
96
100
0
113
0
112
93.2
0
112
100
100
100
0
35.0
14.0
100
Fraction 3
(5 mL hexane
with 10 percent
acetone)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
65.0
86.0
0
"Cannot be quantitated accurately because of interference from Aroclor 1260.
on either the DB-608 or the DB-1701
fused-silica open tubular columns. The
remainder of the 17 organochlorine
pesticides were retained on the silica
cartridge and were then eluted with
hexane with 50 percent diethyl ether.
The diol cartridge procedure was also
evaluated to determine whether
elemental sulfur, if present, can be
separated from the organochlorine
pesticides. It was found that when the
cartridge is eluted with hexane with 10
percent acetone, the elemental sulfur
elutes together with the organochlorine
pesticides and will interfere with the
gas chromatographic analysis of six
organochlorine pesticides on the DB-
1701 column.
Phthalate Esters
Florisil and alumina SPE cartridges
were evaluated for their use in phthalate
ester analysis. These cartridges were
chosen because the current SW-846
Method 8060 recommends use of either
Florisil (Method 3620) or alumina
(Method 3610) for cleanup of sample
extracts containing phthalate esters.
We have evaluated both methods with
hexane solutions containing 16 phthalate
esters. The percent recoveries of the 16
compounds are presented elsewhere (5).
Alumina cleanup is preferred over the
Florisil cleanup since it allows recovery of
all target compounds by elution with
hexane with 20 percent diethyl ether.
When Florisil cleanup was used, bis(2-
methoxyethyl) phthalate (BMEP), bis(2-
ethoxyethyl) phthalate (BEEP), and bis(2-
n-butoxyethyl) phthalate (BBEP) could
not be recovered at all, and dimethyl
phthalate (DMP) and diethyl phthalate
(DEP) gave recoveries of only 40 and 57
percent, respectively.
We used Florisil and alumina SPE
cartridges of 0.5-g, 1.0-g, and 2-g size,
charged them the target compounds and
interferents, and eluted them with 10
percent acetone (for Florisil) or hexane
with 20 percent acetone (for alumina).
The results of the evaluation study are
summarized below:
• The procedure that uses alumina
cartridges and hexane with 20 percent
acetone gave quantitative recoveries
for all compounds except BMEP from
the 2-g cartridges. BMEP was
recovered from the 2-g alum
cartridges by eluting the cartridj
with two additional 5-mL portions
hexane with 20 percent acetone. Ta
5 presents the recovery data for the
g alumina cartridges.
The procedure that uses Flor
cartridges and hexane with 10 perc
acetone gave good recoveries for
16 phthalate esters except BMEP <
BEEP (the 0.5-g and the 1-g Floi
cartridge were eluted with 5
hexane with 10 percent acetone, <
the 2-g cartridges were eluted with
mL of hexane with 10 perc<
acetone).
Corn oil and diesel hydrocarbons
not affect the elution patterns or
recovery of the 16 phthalate est
from either type of cartridge (Table
except for BMEP and BEEP (s
footnotes to Table 6). Elemental sul
if present, is eluted from the Floi
cartridge with hexane with 10 perc
acetone and from the alumi
cartridge with hexane with 20 perc
acetone. Therefore, extracts that
known to contain elemental sul
should be subjected to sulfur clear
-------
Table 3. Percent Recoveries and Button Patterns of 17 Organochlorine Pesticides from 1-g Silica Cartridges in the Presence of Corn Oil and
Diesel Hydrocarbons'
Corn oil as interferents
Diesel hydrocarbons as interferents
Compound
Fraction 1
Fraction 2
Fraction 3
Fraction 1
Fraction 2
Fraction 3
alpha-BHC
gamma-BHC
beta-BHC
Heptachlor
delta-BHC
Aldrin
Heptachlor epoxide
Endosulfan 1
4,4'-DDE
Dieldrin
Endrin
4,4'-DDD
Endosulfan II
4,4'-DDT
Endrin aldehyde
Endosulfan sulfate
4,4'-Methoxychlor
0
0
0
119
0
119
0
0
113
0
0
0
0
103
0
0
0
0
0
0
123
0
120
0
0
120
0
0
13.3
0
114
0
0
0
121
124
114
0
115
0
123
121
0
117
143
109
113
0
66.7
108
110
119
122
111
0
112
0
121
118
0
114
142
106
110
0
64.7
105
107
0
0
0
0
0
0
0
0
0
0
0
0
0
0
26.9
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
31.8
0
0
0
0
0
115
0
112
0
0
120
0
0
14.2
0
115
0
0
0
0
0
0
113
0
110
0
0
118
0
0
16.5
0
109
0
0
0
115
118
106
0
108
0
118
117
0
111
150
106
109
0
55.4
98.2
105
116
120
108
0
111
0
120
119
0
114
156
108
111
0
62.5
103
107
0
0
0
0
0
0
0
0
0
0
0
0
0
0
31.0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
31.6
0
0
* Silica cartridges (Supelco lot SP0161) were used; each cartridge was conditioned with 4 mL hexane prior to use. Each experiment was
performed in duplicate. Each cartridge was spiked with 2 mL of a hexane solution containing the Organochlorine pesticides at 0.5 itglml, the
com oil at 500 ng/mL, and the diesel hydrocarbons at 1000 itg/mL Fraction 1 was eluted with 5 mL hexane, Fraction 2 with 5 mL hexane with
50 percent diethyl ether, and Fraction 3 with 5 mL hexane with 50 percent diethyl ether. Vacuum manifold used was the Analytichem SPS24.
(Method 3660) prior to Florisil or
alumina cartridge cleanup.
• The Organochlorine pesticides, if
present, can be separated from the
phthalate esters using Florisil
cartridges (Table 7). The Organo-
chlorine pesticides are first eluted
from the 1-g Florisil cartridges with 5
ml hexane with 20 percent methylene
chloride. Under these conditions, the
phthalate esters are retained on the
cartridge and are later eluted with
hexane with 10 percent acetone.
Phenols
Silica cartridges were evaluated for
cleanup of sample extracts containing
phenolic compounds derivatized with
pentafluorobenzyl bromide (PFBBr).
Quantitative recoveries of the 18 phenolic
compounds were obtained using 2-g
silica cartridges and hexane with 25
percent toluene as eluant (Table 8).
Matrix interferents such as corn oil,
diesel hydrocarbons, and elemental sulfur
were added to hexane solutions of the
derivatized target phenols at known
concentrations, and the solutions were
then subjected to the silica cartridge
eanup procedure to establish if any
changes occurred in the compound
elution pattern and in their recovery when
matrix interferents were present (Table
9). No change in compound recovery or
elution pattern was observed.
The silica cartridge procedure for the
phenols was tested with three extracts of
environmental samples spiked with the
target compounds at known
concentrations. After spiking the extracts
were derivatized with PFBBr using the
Lee, et al., procedure (2) and cleaned by
the silica cartridge cleanup procedure.
Evaluation of the ASPEC System
The Gilson ASPEC system (Automatic
Sample Preparation with Extraction
Columns), with a modified standard
program, was used to evaluate the silica
and diol cartridges for the cleanup of
extracts containing Organochlorine
pesticides and Aroclor 1260 or
Organochlorine pesticides and corn oil,
diesel hydrocarbons, Aroclor 1260, and
elemental sulfur. Furthermore, three
environmental sample extracts were
processed using the ASPEC system and
0.5-g diol cartridges.
Overall, the method reproducibility
using the ASPEC system with the 0.5-g
diol cartridges is excellent. Thirteen out
of 17 Organochlorine pesticides had
RSDs under 4 percent (Table 10), and
there was no crosscontamination when
interferents were added such as corn oil,
diesel hydrocarbons, and when sample
extracts were used.
Conclusions
Currently, there are no EPA-approved
sample extract cleanup procedures that
specify the use of SPE cartridges. The
only methods specifying SPE cartridges
are Test Method No. SPE- 500, Methods
for Organochlorine Pesticides and
Chlorophenoxy Acid Herbicides in
Drinking Water and Raw Source Water
for Endrin, Lindane, Methoxychlor, and
Toxaphene, and Method 525,
Determination of Organic Compounds in
Drinking Water by Liquid-Solid Extraction
and Capillary Column Gas Chroma-
tography/Mass Spectrometry. Both
methods use such cartridges for sample
preconcentration and not for cleaning or
fractionating the sample extract. Work
presented in this report involves the
development of such simplified extract
cleanup procedures for use with methods
-------
Table 4. Percent Recoveries and Button Patterns of 17 Organochlorine Pesticides from 1-g Diol Cartridges in the Presence of Corn Oil ar
Diesel Hydrocarbons'
Corn oil as interferents
Diesel hydrocarbons as interferents
Compound
Fraction 1
Fraction 2
Fraction 3
Fraction 1
Fraction 2
Fraction 3
alpha-BHC
gamma-BHC
beta-BHC
Heptachlor
delta-BHC
Aldrin
Heptachlor epoxide
Endosulfan 1
4,4' -DDE
Dieldrin
Endrin
4,4' -ODD
Endosulfan II
4,4' -DDT
Endrin aldehyde
Endosulfan sulfate
4,4'-Methoxychlor
121
120
108
120
108
115
120
121
115
118
111
112
111
110
28.6
0
100
119
118
106
119
107
113
116
120
115
116
111
110
108
110
26.8
0
99.0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
73.0
102
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
76.8
108
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
115
116
102
117
108
111
120
120
116
118
116
115
114
114
22.8
0
98.6
116
118
104
119
110
117
122
124
122
120
120
118
115
117
0
0
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
69.8
111
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
42.6
107
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
< Diol cartridges (Supelco lot SP0206) were used; each cartridge was conditioned with 4 ml hexane with 10 percent acetone prior to ust
Each experiment was performed in duplicate. Each cartridge was spiked with 2 mL of a hexane solution containing the organochlorin
pesticides at 0.5 ng/mL, the corn oil at 500 yglmL, and the diesel hydrocarbons at 1000 iig/mL Fractions 1, 2, and 3 were each eluted with
mL hexane with 10 percent acetone in hexane. Vacuum manifold used was the Analytichem SPS24.
presented in the EPA's SW-846
procedures manual.
Use of SPE cartridges reduces solvent
and adsorbent usage and labor cost in
sample preparation. Because cartridges
are prepackaged and ready for use, there
is no need for adsorbent calibration,
activation, or deactivation. Furthermore,
when commercially available automated
systems are used, sets of 12 or 24
extracts, depending on the capacity of
the vacuum manifold, can be cleaned up
simultaneously with no danger of sample
crosscontamination; thus, sample
throughput can be increased significantly.
In addition, errors resulting from operator
and material variables that may affect the
quality of the results can be minimized.
Recommendations
• The protocol for extract cleanup using
SPE cartridges which is presented as
part of the full report has been
evaluated in a single laboratory with a
few relevant sample extracts. To
establish the applicability range of the
cartridge method and to define the
interlaboratory method performance,
the protocol should be evaluated by
other laboratories and with additional
samples.
• Use of SPE cartridges helps increase
sample throughput, and reduces
solvent and adsorbent usage and labor
cost in sample preparation. To take full
advantage of these benefits,
automation of the sample extract step
should be explored. Several robotics
systems which are available
commercially should be evaluated.
• Bonded-phase silicas and polymeric
materials such as those available from
Interaction Chemicals of Mountain
View, California, should be evaluated
for removal of matrix interferents
present in extracts of soils, sediments,
and other environmental matrices, and
for fractionation of analytes of
environmental significance.
References
1. Test Methods for Evaluating Solid
Waste; Laboratory Manual -•
Physical/Chemical Methods, SW-
846, 3rd Edition, Vol 1B, U.S.
Environmental Protection Agency,
Washington, DC, November 1986.
2. Lee, H. B., Weng, L. D., and Chau,
A.S.Y., "Chemical Derivatization
Analysis of Pesticide Residues,
Analysis of Phenol and
Chlorinated Phenols in Natu
Waters by Formation
Pentafluorobenzyl Ether Derivative;
J. Assoc. Off. Anal. Chem. 67, 10J
1090, 1984.
3. Lopez-Avila, V., Schoen, S., Milam
J., and Beckert, W. F., "Sing
Laboratory Evaluation of El
Method 8080 for Determination
Chlorinated Pesticides ai
Polychlorinated Biphenyls
Hazardous Wastes," J. Assoc. C
Anal. Chem. 41,375-387, 1988.
4. Viar and Co., Protocol for SAS 421
QC, November 1988.
5. Lopez-Avila, V., Constantino, I
Milanes, J., and Gale, Ft., "Sing
Laboratory Evaluation of Meth
8060 -- Phthalate Esters," Fir
Report for EPA Contracts 68-03-32
and 68-03-3511, Work Assignmer
2-14, 3-16, and 0-11, Novemb
1989.
6. Junk, G. A., Avery, M. J., a
Richard, J. J., "Interferences
Solid-Phase Extraction Using C
Bonded Porous Silica Cartridge
Anal. Chem. 60, 1347-50, 1988.
-------
Tables. Percent Recoveries and Button Patterns for 16 Phthalate Esters from 1-g Alumina
Cartridges'
Fraction 1
Compound Average Recovery Percent RSD
Dimethyl phthalate (DMP)
Diethyl phthalate (DEP)
Diisobutyl phthalate (DIBP)
Di-n-butyl phthalate (DBP)
Bis(4-methyl-2~pentyl) phthalate (BMPP)
Bis(2-methoxyethyl) phthalate (BMEP)
Diamyl phthalate (DAP)
Bis(2-ethoxyethyl) phthalate (BEEP)
Hexyl 2-ethylhexyl phthalate (HEHP)
Dihexyl phthalate (DHP)
Benzyl butyl phthalate (BBP)
Bis(2-n-butoxyethyl) phthalate (BBEP)
Bis (2-ethylhexyl) phthalate (DEHP)
Dicyclohexyl phthalate (DCP)
Di-n-octyl phthalate (OOP)
Dinonyl phthalate (DNP)
108
129
92.6
107
88.3
92.2
700
707
93.2
773
704
99.5
707
97.2
703
770
4.6
6.6
7.3
5.6
9.8
5.0
6.4
6.3
73
5.4
3.9
4.7
6.7
6.2
7.5
5.2
8 Alumina cartridges (J. T. Baker) were used; each cartridge was conditioned with 4 mL hexane prior
to use. Each experiment was performed in duplicate at three spiking levels (40 jjg, 80 iig, and 720
tig per compound per cartridge). Fraction 1 was eluted with 5 mL hexane with 20 percent acetone.
-------
Table 6. Percent Recoveries of the Phthalate Esters from Florisil and Alumina
Florisil cartridge (Fraction 1)
Compound
DMP
DEP
DIBP
DBP
BMP
BMEP*>
DAP
SEEP"
HEHP
DHP
BBP
BBEP
DEHP
DCP
OOP
DNP
Com oil
(1000 ng per cartridge)
119
133
101
111
104
b
96.6
53.3
89.8
108
106
104
99.9
81.4
109
114
123
133
104
111
104
b
96.8
64.6
91.2
106
107
104
99.4
81 2
108
114
Diesel hydrocarbons
(2000 y.g per cartridge)
106
123
111
110
93.2
b
98.8
43.7
87.1
103
102
98.8
92.1
68.2
102
107
111
129
107
114
95.7
b
98.8
32.3
86.6
104
104
100
94.6
68.2
103
111
Cartridges when Interferents
Alumina cartridge
Com
(WOO ng per
105
120
88.8
92.4
61.2
81.4
82.7
70.9
74.3
99.8
93.8
87.8
83.3
81.8
93.1
98.5
were Present9
(Fraction 1)
oil Diesel hydrocarbons
cartridge) (2000 pg per cartridge)
104
119
87.7
91.1
63.1
81.8
83.1
71.8
82.9
98.9
92.6
87.8
83.1
81.3
92.7
99.2
92.5
92.5
82.8
88.7
69.8
74.1
74.9
66.0
71.1
90.3
84.6
88.3
72.6
72.0
80.9
86.4
94.4
94.4
85.8
90.4
71.0
75.8
76.9
67.9
73.1
91.5
87.3
81.6
74.6
73.8
82.7
68.3
8 1-g cartridges were used for this experiment. Each cartridge was preconditioned with 4 mL hexane. Each experiment was
performed in duplicate. The Florisil cartridge was eluted with two 5-mL portions of hexane with 10 percent acetone (Fractions 1 and
2). The alumina cartridge was eluted with two 5-mL portions of hexane with 20 percent acetone (Fractions 1 and 2).
b BMEP was recovered from the Florisil cartridges. In Fraction 2 at 81.9 and 95.6 percent when corn oil was present as interferent,
and at 71.5 and 62.3 percent when diesel hydrocarbons were the interferents.
c Additional BEEP was recovered from the Florisil cartridge in Fraction 2. The recoveries in Fraction 2 were 41.6 and 31.7 percent
when corn oil was present as interferent, and 56.8 and 63.4 percent when diesel hydrocarbons were the interferents.
-------
Table 7. Percent Recoveries and Elution
Patterns for 16 Phthalate Esters
from i-g Florisil Cartridges in the
Presence of Organochlorme
Pesticides9
Fraction 2
Average Percent
Compound recovery RSD
DMP 130 52
DEP 88.2 2.5
DIBP 118 16
DBP 121 13
BMPP 123 5.7
BMEP 31.9 31
DAP 93.7 34
BEEP 82.1 19
HEHP 126 6.4
DHP 62.0 15
BBP 98.2 6.5
BBEP 135 34
DEHP 110 2.7
DCP 106 3.3
OOP 123 7.0
DNP 102 8.7
a Florisil cartridges (Supelco, Inc.) were
used; each cartridge was conditioned
with 4 mL hexane prior to use. Each
experiment was performed in triplicate.
Table 8. Percent Recoveries and Elution Patterns for 18
Derivatized Phenols
from 2-g Silica
Cartridges'
Fraction 2
Compound
Phenol
2 -Methyl phenol
3 -Methyl phenol
4-Methylphenol
2,4-Dimethylphenol
2-Chlorophenol
2, 6-Dichlorophenol
4-Chloro-3-methylphenol
2,4-Dichlorophenol
2,4,6-Trichlorophenol
2,3,6-Trichlorophenol
2, 4,5-Tnchlorophenol
2,3,5- Trichlorophenol
2,3,5, 6-Tetrachlorophenol
2,3,4,6- Tetrachlorophenol
2,3,4-Trichlorophenol
2,3,4,5-Tetrachlorophenol
Pentachlorophenol
Average
recovery
74.1
84.8
86.4
82.7
91.8
88.5
90.4
94.4
945
978
95.6
92.3
92.3
97.5
97.0
72.3
95.1
962
Percent
RSD
5.2
5.2
4.4
5.0
5.6
5.0
4.4
7.1
7.0
6.6
7.1
8.2
8.2
5.3
6.1
8.7
6.8
8.8
The spiking level was 500 ng per
compound per cartridge. Fraction 1 which
contained all organochlorine pesticides
was eluted with 5 mL hexane with 20
percent methylene chloride, Fraction 2
with 5 mL hexane with 10 percent
acetone. No phthalate esters were
detected in Fraction 1.
a Silica cartridges (Supelco, Inc) were used: each
cartridge was conditioned with 4 mL hexane prior to use.
Each experiment was performed in duplicate at three
spiking levels (0.1 \ig, 0.2 fig, and 0.4 yog per compound
per cartridge). Fraction 1 was eluted with 5 mL hexane
and was discarded. Fraction 2 was eluted with 5 mL
hexane with 25 percent toluene
-------
Table 9. Percent Recoveries and Elution Patterns of Derivatized Phenols from 1-g Silica Cartridges in the Presence of Corn Oil and
Diesel Hydrocarbons'
Com oil as interferent
Diesel hydrocarbons as interferents
Compound
Phenol
2-Methylphenol
3-Methylphenol
4-Methylphenol
2,4-Dimethylpehenol
2-Chlorophenol
2, 6-Dichlorophenol
4-Chloro-3-methylphenol
2,4-Dichlorophenol
2,4,6-Trichlorophenol
2,3,6-Trichlorophenol
2-Nitrophenol
2, 4,5-Trichlorophenol
2,3,5-Trichlorophenol
2, 3, 5, 6-Tetrachlorophenol
2,3,4,6-Tetrachlorophenol
2,3,4-Trichlorophenol
2,3,4,5-Tetrachlorophenol
Pentachlorophenol
2,4-Dinitrophenol
Fraction
0
5.0
0
0
0
0
35.8
0
0
87.0
67.6
ND»
0
0
88.4
93.6
0
0
74.9
ND
1
0
0
0
0
0
0
18.9
0
0
81.6
45.5
ND
0
0
83.1
83.4
0
0
70.7
ND
Fraction
68.8
85.9
82.8
71.0
84.2
80.6
63.1
78.9
80.7
0
33.2
ND
126
126
0
4.7
76.5
82.0
0
ND
2
69.4
87.9
83.8
68.6
84.8
80.9
72.8
78.4
80.3
8.1
48.7
ND
125
125
5.0
9.9
76.6
81.8
0
ND
Fraction
0
0
0
0
0
0
9.9
0
0
76.4
34.9
ND
0
0
78.4
80.0
0
0
66.5
ND
1
0
7.0
0
0
0
0
30.6
0
0
86.0
57.1
ND
0
0
89.7
93.3
0
0
76.4
ND
Fraction
57.6
77.9
75.1
62.0
74.6
77.6
69.0
70.8
77.4
6.5
46.2
ND
118
118
0
7.9
74.5
74.4
5.3
ND
2
61.2
80.6
79.6
66.2
80.1
77.0
64.2
75.6
77.6
6.6
37.2
ND
123
123
5.1
8.1
78.0
81.6
4.8
ND
« 1-g silica cartridges (J. T. Baker lot B51505) were used in this experiment. Each cartridge was conditioned with 4 mL hexane prior
to use. Fraction 1 was eluted with 5 mL hexane. Fraction 2 was eluted with 5 mL hexane with 25 percent toluene. Spiking level was
0.4 itg of derivatized phenols per cartridge.
* ND •- not detected.
10
-------
Table 10. Method Reproducibility Using the ASPEC Robotic
System'
Compound
alpha-BHC
gamma-BHC
beta-BHC
Heptachlor
delta-BHC
Aldrin
Heptachlor epoxide
Endosulfan 1
4,4' -DDE
Dieldrin
Endrin
4,4' -ODD
Endosulfan II
4,4'-DDT
Endrin aldehyde
Endosulfan sulfate
4,4'-Methoxychlor
Average recovery
86.1
87.1
81.9
86.1
83.8
86.2
86.0
85.3
85.4
86.3
108
84.0
84.6
84.7
52.9
58.1
79.4
Percent RSD
3.0
2.9
3.3
3.2
3.2
3.2
3.3
3.6
3.4
3.3
4.5
3.7
3.3
3.6
4.9
10
4.6
a0.5-g diol cartridges (Supelco, Inc.) were used for this experiment.
Each cartridge was conditioned with 4 mL hexane with 10 percent
acetone (speed 5, air volume 100 i*L). Standard in hexane (1 mL)
was added to the cartridge (height 0, speed 4, air volume 100 nL).
The cartridge was eluted with 3.5 mL hexane with 10 percent
acetone (speed 4, air volume 200 fiL). Finally, to clean the lines, the
cartridge was rinsed with 1 mL hexane with 10 percent acetone
(speed 8) and the rinse was discarded. Spiking level was 1 fig per
cartridge. All fractions were adjusted to 5 mL final volume. The
number of determinations was 19.
11
-------
Viorica Lopez-Avila, Janet Benedicto, and June Milanes are with Acurex Corp.,
Mountain View, CA 94039-7044. The EPA author Werner F. Beckert (also
the EPA Project Officer) is located at the Environmental Monitoring
Systems Laboratory, Las Vegas, NV 89193-3478.
Werner F. Beckert is the EPA Project Officer (see below).
The complete report, entitled "Evaluation of Sample Extract Cleanup Using Solid-
Phase Extraction Cartridges," (Order No. PB 90-162 5201 AS; Cost: $23.00,
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:
Environmental Monitoring Systems Laboratory
U.S. Environmental Protection Agency
Las Vegas, NV 89193-3478
United States Center for Environmental Research
Environmental Protection Information
Agency Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S4-89/049
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