ACID/NEUTRAL CONTINUOUS LIQUID/LIQUID
EXTRACTION OF PRIORITY POLLUTANTS AND
HAZARDOUS SUBSTANCE LIST COMPOUNDS
ENVIRONMENTAL PROTECTION AGENCY,
ANNAPOLIS, MD. CENTRAL REGIONAL LAB
JAN 1988
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION) III
CENTRAL REGIONAL LABORATORY
839 BESTGATE ROAD
ANNAPOLIS. MARYLAND 21001
'f*
Acid/Neutral Continuous Liquid/Liquid
Extraction of Priority Pollutants
and Hazardous Substance List Compounds
Joseph L. Slayton and E. Ramona Trovato
Environmental Protection Agency
EPA/903-9-88-001
-------
4. TITLE AND SUBTITLE
Acid/Neutral Continuous Liquid/Liquid Extraction
of Priority Pollutants and Hazardous Substance
List Compounds
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before com/1'
REPORT NO.
EPA/903-9-88-001
2.
5. REPORT DATE
Date of Issue
6. PERFORMING ORGANIZATION CODE
January 1988
AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
Joseph L. Slayton, E. Ramona Trovato
9. PERFORMING ORGANIZATION NAME AND ADDRESS
USEPA Central Regional Laboratory, Region III
839 Bestgate Road
Annapolis, Maryland 21401
10. PROGRAM ELEMENT NO.
1 1. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
Presented at the 28th Rocky Mountain Conference, Denver, Colorado, August 6, 1986
16. ABSTRACT
Continuous liquid-liquid extraction was compared to manual extractions per EPA
Method 625, but employing an acid-neutral scheme. The results from EPA performance
evaluation (quality control) wastewater, Superfund, and RCRA samples are compared
using the two extraction techniques. Continuous liquid-liquid extractions following
an acid-neutral scheme were compared to those following a base-neutral scheme.
The acid-neutral continuous extraction scheme was determined to be effective,
elegant and labor-saving. Emulsion formation was reduced and the recoveries'of
phenol, 4-nitrophenol, pentachlorophenol and benzo'ic acid were significantly
improved by using the continuous extractor. The acid-neutral scheme as opposed
to the Method 625 base-neutral extraction was found to greatly improve the recovery
of dimethyl-, diethyl-, di-n-butyl-, and n-butyl benzyl phthalate esters. The
levels of target and additional compounds extracted using a continuous extractor
from the environmental samples tested equaled or exceeded those obtained from
manually extracted samples. The distribution of target compounds in the acid-neutral
and base fraction was determined by analyses of performance evaluation samples.
All identifications and quantisations were performed using GC/MS systems with
fused capillary columns.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group
Priority Pollutants.. .Hazardous Substances
...detection of, in wastewater, test
wells, lab water, by continuous
extraction employing GC/MS
Acid Neutral Extraction
Base Neutral Extraction
Semi-Volitale Organics
Continuous Extraction
Liquid/Liquid Extraction
Gas Chromatography/Mass
Soectrometrv
18. DISTRIBUTION STATEMENT
Release Unlimited
21. NO. OF PAGES
REPRODUCED BY 66
U.S. DEPARTMENT OF COMMERCE
NATIONAL TECHNICAL
INFORMATION SERVICE
SPRINGFIELD, VA. 22161
,7
22.
EPA Form 2220-1 (9-73)
-------
Acid/Neutral Continuous Liquid/Liquid
Extraction of Priority Pollutants
and Hazardous Substance List Compounds*
Joseph L. Slayton1" and E. Ramona Trovato
Environmental Protection Agency
Central Regional Laboratory
839 Bestgate Road
Annapolis, Maryland 21401
January 1988
Abstract
Continuous liquid-liquid extraction was compared to manual extractions
per EPA Method 625, but employing an acid-neutral scheme. The results
from EPA performance evaluation (quality control) wastewater, Superfund,
and RCRA samples are compared using the two extraction techniques.
Continuous liquid-liquid extractions following an acid-neutral scheme
were compared to those following a base-neutral scheme. The acid-
neutral continuous extraction scheme was determined to be effective
elegant and labor saving. Emulsion formation was reduced and the
recoveries of phenol, 4-nitrophenol, pentachlorophenol and benzoic acid
were significantly improved by using the continuous extractor. The
acid-neutral scheme as opposed to the Method 625 base-neutral extraction
was found to greatly improve the recovery of dimethyl-, diethyl-,
di-n-butyl-, and n-butyl benzyl phthalate esters. The levels of target
and additional compounds extracted using a continuous extractor from
the environmental samples tested equaled or exceeded those obtained
from manually extracted samples. The distribution of target compounds
in the acid-neutral and base fraction was determined by analyses of
performance evaluation samples. All identifications and quantisations
were performed using GC/MS systems with fused capillary columns.
*Presented August 6, 1986 at the Rocky Mountain Conference, Denver, Colorado.
^Author to whom correspondence should be addressed.
i
-------
Pi sclaimer:
The mention of trade names or commercial products in this report is for
i1lustrational purposes and does not constitute endorsement or recommendation
by the II. S. Environmental Protection Agency.
-------
Introduction
The EPA procedure for the analysis of water samples for the National
Pollution Discharge Elimination System (NPDES) includes the extraction of
certain priority pollutants into methylene chloride. A detailed description
of this Method 6?5 may be found elsewhere (1). The procedure details the
extraction of a water sample after adjustment to a pH>ll. The extraction
is repeated after the sample pH is re-adjusted to pH
-------
and a single analysis was performed on a FSCC. This extraction scheme
recovered chlorinated hydrocarbon pesticides found to extract poorly by
Method 625. The poor recovery of Method 625 was attributed to chemical
reactions occurring among organic compounds in aqueous solutions under
strongly basic (pH>ll) conditions (4).
The EPA Method 625 includes the optional use of a continuous liquid/ liquid
extractor which is recommended when an emulsion is formed during manual
extraction (separatory funnel). The term "continuous extractor" in the
EPA method, as well as in this report, refers to a batch type extractor
(5,6) employing a fixed volume of sample and solvent. The sample is
continuously extracted as boiling solvent, methylene chloride (specific
gravity 1.355 4), condenses and drips through the sample. The solvent
returns via a siphon tube to the boiling solvent flask.
The purpose of this report was to document the extraction efficiencies
obtainable for a broad category of organic compounds with a simple
extractor (Figure 1) as well as to relate the effect of reversing the pH
scheme employed in Method 625. In this acid/neutral extraction, the sample
pH was first adjusted to pH<2 thus resulting in an acid/neutral extract
(A/N). The sample pH was subsequently readjusted to pH>ll and again
extracted, resulting in a base extract. The priority pollutant and hazardous
substance (HS) list compounds tested by this extraction procedure were
those defined by the EPA for the Superfund program (7) including such HS
compounds as: benzoic acid; 2-methylphenol; 4-methylphenol; 2-methyl-
naphthalene; and 3-nitroaniline. In addition, extraction efficiencies
-------
were measured and compared using the continuous acid/neutral and the manual
(separatory funnel) acid/neutral extraction schemes for other (non-target)
compounds present in sewage, river water, industrial effluents and ground
water.
Experimental Section
I. Procedures
A. Continuous Extraction
The continuous extractor (CE) was a simple, inexpensive, all glass
design obtained from Perpetual Systems, Rockville, MD. The extractor
(Figure 1) stands 35 cm tall and is 10 cm in diameter. Cool water
for the Allihn condenser was provided by a re-circulating chiller
(Neslab Coolflow 75). The CE itself was first loaded with
approximately 300 ml of CH2Cl_2 and 350 ml of CHzCl? was placed
in the solvent flask. One liter of spiked laboratory pure water
or environmental sample was then placed in the extractor. For the
acid/neutral extraction scheme, the pH was first adjusted to pH<2
with 6N H2S04 using ColorphastR (MCB Reagent, Gibbstown, NJ) test
strips on drops of sample removed with a large glass stirring rod.
The condenser was placed on the apparatus and the solvent flask
was heated to boiling. A rheostat was employed to adjust the
boiling rate to give a solvent flow of approximately 6 mL/minute.
The extraction was carried out for 24^2 hours and then the aqueous
pH was re-adjusted to pH>ll with 6N NaOH. A fresh flask of methylene
chloride was then attached and extracted for 24+2 hours. In the
-------
FIGURE 1. LIQUID-LIQUID EXTRACTOR
35cm
Allihn type reflux condenser
LL-1000
Perpetual Systems Corporation
Scientific Division
2283 Lewis Avenue
Rockville. Mjrylind 20851 (JOD770O390
-------
experiments with laboratory pure water spikes, the two solvent
extracts were kept separate and GC/MS analyzed separately. In the
experiments with environmental samples, the extracts were combined
before concentration. The extract(s) were dried through sodium
sulfate and concentrated to 1 ml by KD-evaporation with a water
bath at 60-65°C as per EPA Method 6?5 (1). A reagent blank of
laboratory pure water was carried through this procedure with each
experiment. In the case of the base/neutral extraction scheme
(Method 625), the sample pH adjustment for the first extraction
was performed at pH>ll.
Four separate spiking experiments were performed with laboratory
pure water. These included:
I. A priority pollutant cocktail spike.
II. Additional compounds mixture spike.
III. Basic compound spikes.
IV. Pesticide spike.
A detailed description of these spiking materials is provided in the
Materials Section.
B. Manual Extraction
For each extraction, a 1-liter aliquot of sample or spiked laboratory
pure water was placed in a 2-L separatory funnel. The procedure
employed was essentially that outlined by EPA Method 625 (1) with
the exception that this manual acid/neutral scheme involved the
initial adjustment of the sample to pH<2. In brief, after the pH
-------
adjustment the extraction was carried out by shaking 60 ml of
methylene chloride with the sample for 2 minutes. The solvent was
dried through sodium sulfate and collected directly in a KD apparatus,
This procedure was repeated three times and then the sample pH was
readjusted to pH>ll and the process repeated. As with the continuous
extractor, the A/N and base extracts were concentrated to 1 ml
separately for the laboratory pure water spiking experiments. In
the environmental sample experiments, the extracts were combined
before concentration and analyzed as a single extract. The same
four spiking experiments in laboratory pure water were conducted
employing manual extraction except that the following compounds
were not included: benzyl alcohol; dibenzofuran; 2-methylphenol ,
4-methylphenol , 2,4-dinitrophenol; N-nitrosodiphenylamine.
Throughout this work every effort was made to perform the sodium
sulfate drying and KD concentration steps as uniformly as possible
since losses during these steps would affect the measured recoveries.
C. GC/MS Systems
The analyses were performed with Finnigan Model 4023 and 4500 mass
spectrometer systems interfaced to Finnigan Model 9610 gas chroma-
tographs. The fused silica capillary columns employed were 30 m x
0.32 mm i.d. x 1.0 urn film thickness Supelco SPB-5 (5% diphenyl-/94%
dimethyl-/I% vinyl-polysiloxane). The columns were connected
directly into the spectrometer ion sources. The injections were
performed with Grob-type injectors in the splitless mode with
8
-------
sweep (15 mL/minute) and split (25 mL/minute) flows stopped for 30
seconds during injection. The carrier gas was ultrapure helium
with a linear velocity of 38 cm/sec at 100°C. The injector temperature
was 270°C and the temperature of the ion source was 270°C. The GC
oven was programed at 30°C for 2 minutes followed by a 10°C/minute
ramp to 300°C. Cryogenic cooling was provided by GC-regulated
liquid nitrogen flow. The scan rate of the spectrometer was controlled
by a Data General Nova 3 computer and was set at 35 to 450 AMU at
0.8 seconds per scan. The ionization mode employed was electron
impact at 70 eV.
11. Materials
The materials employed were of the quality specified by EPA Method
625 (1). The boiling stones employed were si Icon carbide granules
(Carborundum" #12 granules, Hengar Co., Philadelphia, PA), which were
found to be less porous and absorptive than ceramic boiling aids. All
glassware, glass wool- and sodium sulfate were fired at 500°C employing
a Blue M Model CFD 20F oven (Blue M Electric Co., Blue Island, Illinois).
This oven allowed a gradual temperature change which was less stressful
to fragi le glassware.
A. Priority Pollutant Mixture
Three quality control (OC) standards WP482 #1 and #3 (non-phenolics
in acetone) and WP881 #1 (phenolics in methanol) were obtained from
EPA, Environmental Monitoring and Support Laboratory (EMSl) Cincinnati,
-------
A synthetic sample was prepared by adding 1-ml of each of these OC
standards to a single 1-liter volume of laboratory pure water.
B. Basic Compounds
Stock solutions of: benzidine (EC 26-01-02 in methanol); 3,3'-dichloro-
benzidine (EC 5-01-02 in methanol); and anilines (C075 in benzene)
were obtained from the EPA Ouality Assurance Materials Bank, Research
Triangle Park (RTP), NC.
C. Pesticides
A stock solution (C043 in toluene-hexane) was obtained from EPA (RTP).
D. Additional Compounds
The following extractable priority pollutants and hazardous substance
list (HSL) compounds were obtained as neat materials from Chem
Service, Inc., West Chester, PA: benzyl alcohol (HSL); dibenzofuran
(HSL); 2-methylnaphthalene (HSL); 2,4,5-trichlorophenol (HSL);
N-nitrosodiphenylamine. Stock solutions at 1,000 ng/uL were prepared
in methanol (MeOH). In addition, the following compounds were
obtained as stock solutions from the EPA Ouality Assurance Materials
Rank (RTP) and were analyzed separately:
N-nitrosodimethylamine (5000 ug/ml MeOH)
hexachlorocyclopentadiene (5000 ug/mL MeOH)
acenaphthylene (5000 ug/mL MeOH)
indeno(l,2,3-cd) pyrene (500 ug/mL acetone)
2-methylphenol (HSL) (5000 ug/mL MeOH)
4-methylphenol (HSL) (5000 ug/mL MeOH)
2,4-dinitrophenol (5000 ug/mL MeOH)
10
-------
E. Pally Standard(s)
Standards for the target compounds were prepared at 20 ng/uL,
50 ng/uL, and 80 ng/uL from EPA (RTP) stock solutions (C039, C040,
C041, C044) in methylene chloride and 1 uL was analyzed daily. In
addition standards of the basic compounds, anilines and benzidenes
(EC 26-01-02, EC 5-01-02, and C075), were analyzed daily at 50 ng/uL
(50 ng injected).
F. Internal Standard(s)
Stock solutions of the following internal standards were purchased
from Supelco, Bellefonte, PA (Supelpreme Internal Standards, 4000
ng/uL in methylene chloride): 04-1,4-dichlorobenzene; D8-naphthalene;
DIO-acenaphthene; DIO-phenanthrene; D12-chrysene; 012-perylene.
This solution was spiked (10 uL) into each 1 ml extract concentrate
and standard solution just prior to GC/MS analysis.
G. Laboratory Pure Water (reagent water)
Laboratory pure water was obtained by passing the effluent of a
Milli-R015 system (Millipore Co., Redford, Mass.) through a 45 cm
x 9 cm diameter glass/stainless steel cylinder containing charcoal.
III. Partition Experiment
A priority pollutant mixture spiking experiment was performed at pH<2
with a continuous extractor that had a stopcock in the solvent siphon
line (return line). To the extractor was added: 300-350 mL of methylene
chloride; 1000 ml of spiked laboratory water containing 1 ml of WP482 #1,
11
-------
WP482 #3, and WP881 #1; sulfuric acid to pH<2, and the stopcock closed.
One flask (350 mL methylene chlorine) of solvent was boiled over in 53
minutes. The temperature of the aqueous sample was 29°C. The heat
was removed and the stopcock opened to collect all of the solvent.
This solvent was Na£S04 dried and KD concentrated to 1 ml.
IV. Quantisation
Concentrations were determined against a single 50 ng standard in the
spiking experiments and against a three point standard curve for the
environmental samples. Response factors were computed from quantisation
ion peak areas (Areax) versus the closest eluting internal standard as:
Response factor = (Areax) (Cone. Int. Std.)
(Conc.x) (Area Int. Std.)
The quantisation ion selected for each compound was that specified in
the EPA Superfund (CERCLA) Program (7).
In the spiking experiments, a reference solution was prepared using
the same material in the same amount as that spiked into the laboratory
pure water (synthetic sample), but diluted to 1 mL in methylene chloride.
The reference solution was added to a ?. ml teflon septum vial and
stored in a freezer (-20°C) until the extraction was completed. At
that time each sample extract and reference solution was spiked with
10 uL of the internal standards solution. The recoveries reported
for the spiking experiments were calculated as:
% recovery = 100 x GCMS measured concentration with extraction
GCMS measured concentration with direct
injection of reference solution
12
-------
The quality control sample of the phenolic compounds was in methanol
(WP881 #1). This reference mixture was observed to give split
chromatographic peaks on FSCC. The areas of the peaks were combined
to give the total area used in the % recovery calculations.
For environmental samples, the concentration of the target compounds
(CERCLA) were determined against a three point standard curve consisting
of: a plot of areax/area of internal standard vs. concentration. This
response ratio was determined relative to the closest internal standard.
On occasion an environmental sample was analyzed which had target
compound concentrations ranging from trace to macro amounts. In these
instances an alternate quantitation ion (less abundant ion) was selected
for the quantitation of the compounds(s) present in high concentration
to allow a greater dynamic range. Some sample extracts required
dilution and re-analysis to bring the very high level contaminant
target and or non-target compounds to within the standard curve working
range. In all cases the quantitation procedures used were the same
for the extraction schemes being compared.
With the exception of closely eluting target compound isomers
(dichlorobenzenes; methylphenols; phenanthrene and anthracene;
benzo(A)anthracene and chrysene; benzo(B)fluoranthene and .
benzo(K)f1uoranthene), the search for the quantitation ions in a
relative retention time window and calculations of concentration were
performed automatically by the Finnigan AutoQU program. The exceptions
13
-------
required manual determination of the chromatographic peak areas and
manual calculation of analyte concentration. All target identifications
were verified by a review of the mass spectra.
For target compounds, in general, a "J" recorded next to a numerical
value indicates a concentration value below the level of accurate
quantisation. The presence of the compound has been verified by mass
spectral information but the quantity reported is an estimate. An
"ND" value denotes values which were not detected.
In addition, for environmental samples, compounds other than the target
list (for which standards were analyzed daily) were searched against
the EPA-NIH National Standard Reference Data System. This is a specral
library of 38,750 compounds commonly called the "NBS Library".
Quantitation of these "tentatively identified compounds" was based
on an assumed response factor of 1.0 relative to the nearest eluting
internal standard. All calculations of the concentrations of these
compounds were performed with an automatic program entitled Cmixed.
This Fortran program is available from the authors.
V. Qua!ity Control
Before the analysis of any sample extracts the mass spectrum of
bis(perfluorophenyl)phenylphosphine (DFTPP) was measured and found
to be within EPA criteria (Method 625) or the necessary instrument
adjustments were performed. At least one standard for all target
14
-------
compounds was analyzed daily to verify acceptable spectrometer and
chromatographic performance. Reagent blanks were routinely analyzed
to assure the lack of background contamination.
Results and Discussion
I. Priority Pollutant Cocktail Spiking Experiment
A. Acid/Neutral Extraction Scheme Employing the Continuous Extractor
A single mixture of forty-eight priority pollutants was created by
spiking three quality control samples into laboratory pure water.
This mixture was extracted in four separate replicate extractions
using continuous extractors employing an acid/neutral extraction
scheme. The total ion chromatogram of the mixture is illustrated
in Figure 2, which also includes six internal standards. The
effort was to create a complex mixture to allow possible chemical
reactions to occur under extractor conditions. The compounds
represented broad classes including phenolics, polynuclear aromatics,
ethers, and phthalate esters. The average recovery obtained for
each compound ranged from 88.8% for hexachloroethane to 118% for
pentachlorophenol (Table 1 and Figures 3 and 4). The true values
listed in this table were those provided with the quality control
samples. With the exception of 2-methyl-4,fi-dinitrophenol (MDNP)
all of the recoveries obtained were within the QC (quality control)
limits listed for Method 625. The average recovery obtained for
MDNP was 108% and the required QC acceptance limit was 53-100%.
The standard deviations of the recoveries for these forty-eight
15
-------
RIC
95/19/86 13:28:88
SAMPLE: CE
CONDS.: 4508 30C 2
RANGE: G 1,3400
DATA: ACEAN2 #499
CALI: CAL0324 #3
SCANS 600 TO 3200
MIN TO 300C AT 10C/MIN
LABEL: N 0, 4.0 QUAN:
A 0, 1.0 J 0 BASE: U 20, 3
0.0-,
RIC
T
1000
13:29
CD
O
TO
cn >— i
t— i TD
^ O
CD I—
X — I
-o :&
m -z.
2 o
m CD
-
1
1500
20: no
2000
26:40
2500
33:20
40:00
SCAN
TIME
-------
TABLE 1.
ACID NEUTRAL CONTINUOUS EXTRACTION 5/B6
EPA EHSL AUDITS: HP482I1 HP482I3 HP881I1
I RECOVERY
NO. coipound
1 phenol
2 l,l-oxybis(2-chloroethane)
3 2-chlorophenol
4 1.3-dichlorobenzene
5 !,4-dichloroben:ene
6 1,2-dichlorobenzene
7 bi5(2-chloroisopropyl)ether
B N-nitroso-di-n-propy!a«ine
9 hexachloroethane
10 nitrobenzene
11 3,5,5-triiethyl-2-cyclohexen-l-one
12 2-nitrophenol
13 2,4-dinethylphenol
14 bis(2-chloroethoxy)iiethane
15 2.4-dichlorophenol
16 1,2,4-trichlorobenzene
17 naphthalene
IB 1.1.2.3,4,4-hexachloro-l,3-butadiene
19 4-chloro-3-§ethylpheno)
20 2,4.6-trichloroohenol
21 2-chloronaphthalene
22 diiethylphthalate
23 2.6-dinitrotoluene
24 1,2-dihydroacenaphthvlene
25 4-nitrophenol
26 2,4-dinitrotoluene
27 diethylphthalate
2B l-chloro-4-phenoxybenzene
29 9H-fluorene
30 2-»ethyl-4,6-dinitrophenol
31 4-bro«ophenyl-phenylether
32 hexachlorobenzene
33 pentachlorophenol
34 phenanthrene
35 anthracene
36 di-n-butylphthalate
37 Huoranthene
38 pyrene
39 n-butyl benzyl phthalate
40 bis(2-ethylhexyl)phthalate
41 benzolalanthracene
42 chrysene
43 di-n-octylphthalate
44 benzolblfluoranthene
45 benzolklfluoranthene
46 benzo(a)pyrene
47 dibenzo(a,h)anthracene
4B benzo(ghi)perylene
ppb
true
value
100
48.2
30
52
24.8
24.7
38.8
34.8
30
76.5
76.7
50
30
48.6
50
25.3
24.8
49.6
75
25
25.4
40
76.5
19.5
50
73.8
25.1
76.7
51.2
250
41.5
35.7
75
40.2
40
24.9
29.8
60.2
51.3
29.1
73.9
69.9
43.9
40
45.7
24.9
40.7
80.4
11
94.5
93.8
94.5
89
98.2
98.2
97
95.4
89.5
96.1
89.8
105
109
94.8
96.7
92.7
93.2
90.9
101
116
96
100
95.5
92.9
111
91.5
88.2
94
94.8
107
99.8
93.8
115
92.9
90.5
99.6
94
88.2
95.8
97.5
90.8
91.4
88.7
90.8
91.4
94.6
91.9
90.3
12
93.5
97.5
91.3
92.6
100
100
101
99.5
92.4
98.4
92.4
103
103
99
94.1
97.6
97.6
94.5
96.7
106
96.8
101
95.8
96.9
105
103
92
92.2
95.2
114
99.8
94
117
94.3
93.1
103
99.3
90.2
101
101
95.3
91.5
92.7
95.3
91.5
98
92.9
83.6
13
94.8
93
94.3
92
96.4
92.9
91.8
95.8
85.8
93.1
93.1
102
102
96.2
95.3
92.4
91.9
92.8
98.2
106
94.8
93.6
95.7
90.8
107
96.4
91.4
91. B
93.1
107
86.9
88.3
123
94
91
99.6
98.9
91.7
94.9
91.3
90.7
91.4
89.6
89.5
86.3
92.6
87.2
91.1
14
91.3
96.6
91.6
94.6
98.2
95.9
94.8
97.2
87.5
95.4
95.4
99
94.8
100
93
96
94.2
95.4
94.9
106
98.4
100
too
92.2
99.4
104
96.7
97.5
98.8
103
96.4
97.3
118
95.4
91.2
101
94.4
93.6
94.1
92.3
92
94.4
95.2
96.1
88.6
94
92.6
94.3
AVERAGE
RECOVERY
93.5
95.2
92.9
92.1
98.2
96.8
96.2
97
88.8
95.8
92.7
102.3
102.2
97.5
94.8
94.7
94.2
93.4
97.7
108.5
96.5
98.7
96.8
93.2
105.6
98.7
92.1
93.9
95.5
107.8
95.7
93.4
118.3
94.2
91.5
100.8
96.7
90.9
96.5
95.5
92.2
92.2
91.6
92.9
89.5
94.8
91.2
89.8
STD.
DEV.
1.6
2.2
1.7
2.3
1.5
3.1
3.9
1.9
2.8
2.2
2.3
2.5
5.8
2.4
1.6
2.5
2.4
2
2.6
5
1.5
3.4
2.2
2.6
4.8
5.9
3.5
2.6
2.4
4.6
6.1
3.7
3.4
1
1.1
1.6
2.8
2.3
3.1
4.6
2.1
1.5
3
3.3
2.5
2.3
2.7
4.5
EPA 625
REQUIRED
RECOVERY
16.6-100
42.9-126
36.2-120
16.7-154
37.3-106
48.6-112
62.8-139
13.6-198
55.2-100
54.3-158
46.6-180
45.0-167
41.8-109
49,2-165
52.5-122
57.3-129
35.6-120
37.8-102
40.8-128
52.4-129
64.5-114
D-100
68.H37
60.1-132
13.0-107
47.5-127
D-100
38.4-145
71.6-108
53-100
64.9-114
7.8-142
38.1-152
65.2-109
43.4-118
8.4-111
42.9-121
69.6-100
D-140
28.9-137
41.8-133
44.1-140
18.6-132
42.0-140
25.2-146
31.7-148
D-200
D-195
17
-------
I
•z.
V^
fc
U)
I
U
UJ
ir
u
I
I
120
110
100
FIGURE 3.
ACID NEUTRAL CONTINUOUS EXTRACTION 5/86
WP4B2#1 WP4fl2#3 WP8B101
70
9 11 13 15 17 19 21 23
COMPOUND NUMBER
NO. COMPOUND
1 phenol
2 l,l-oxybis(2-chloroethane)
3 2-chlorophenol
4 1,3-dichlorobenzene
5 1,4-dichlorobenzene
6 1,2-dichlorobenzene
7 bis(2-chloroisopropyl)ether
8 N-nitroso-di-n-propylamine
9 hexachloroethane
10 nitrobenzene
11 3,5,5-trimethyl-2-
cyclohexen-1-one
12 2-nitrophenol
ppb NO. COMPOUND ppb
2,4-dimethylphenol 30
bis(2-chloroethoxy)methane 48.6
2,4-dichlorophenol 50
1,2,4-trichlorobenzene 25.3
naphthalene 24.8
l,l,2,3,4,4-hexachloro-l,3- 49.6
butadiene
4-chloro-3-methylphenol 75
2,4,6-trichlorophenol 25
2-chloronaphthalene 25.4
dimethylphthalate 40
2,6-dinitrotoluene 76.5
1,2-dihydroacenaphthylene 19.5
100
48.2
30
52
24.8
24.7
38.8
34.8
30
76.5
76.5
50
13
14
15
16
17
18
19
20
21
22
23
24
18
-------
FIGURE 4.
ACID NEUTRAL CONTINUOUS EXTRACTION 5/86
WP4B201 WP48203 WPB8101
I
Ul
I
u
u
an
u
o
25 27 29 31 33 35 37 39 41 43 45 47
COMPOUND NUMBER
70
NO. COMPOUND • ppb
25 4-nitrophenol 50
26 2,4-dinitrotoluene 73.8
27 diethylphthalate 25.1
28 l-chloro-4-phenoxybenzene 76.7
29 9H-fluorene 51.2
30 2-methyl-4,6-dinitrophenol 250
31 4-bromophenyl-phenylether 41.5
32 hexachlorobenzene 35.7
33 pentachlorophenol 75
34 phenanthrene 40.2
35 anthracene 40
36 di-n-butylphthalate 24.9
NO. COMPOUND
37 fluoranthene
38 pyrene
39 n-butyl benzyl phthalate
40 bis(2-ethylhexyl)phthalate
41 benzo(a)anthracene
42 chrysene
43 di-n-octylphthalate
44 benzo(b)fluoranthene
45 benzo(k)fluoranthene
46 benzo(a)pyrene
47 dibenzo(a,h)anthracene
48 benzo(ghijperylene
PPb
29.8
60.
51.
29,
73.9
69.9
43.9
40
45.7
24.9
40.7
80.4
19
-------
compounds ranged from 1.0% for phenanthrene (40.2 ug/L spike
level) to 6.1 % for 4-bromophenylphenyl ether (41.5 ng/L spike
level). No compounds were detected in the base extract after the
acid neutral extraction. In addition the solvent below the aqueous
sample was analyzed after the completion of the experiment and no
compounds were detected.
B. Acid/Neutral Continuous Extraction vs. Acid/Neutral Manual
Extraction
The results of the manual (separatory funnel) extraction of the
laboratory pure water spiked with a priority pollutant cocktail
are listed in Table 2. A comparison of the average recoveries by
these two extraction schemes is presented in Figure 5 in which
the difference in the % recovery (continuous minus manual extraction
recovery) was plotted for each compound. There was good agreement
between the two extraction schemes as can be seen by the differences
in % recovery oscillating near zero in Figure 5. However, there
are five notable exceptions (detailed in Table 3): phenol;
2-chlorophenol; l,l,2,3,4,4-hexachloro-l,3-butadiene; 4-nitrophenol ;
and pentachlorophenol. The recoveries of three hydrophilic phenolics
(phenol, 4-nitrophenol and pentachlorophenol) were observed to
improve when employing continuous extraction. The recoveries of
all of the phenolic compounds have been compiled in Table 4.
20
-------
TABLE 2.
CONTINUOUS VS. MANUAL A/N EXTRACTION
EPA EHSL AUDITS: MP482H1 KP482I3 HP881I1
NO. coipound
1 phenol
2 l.l-oxybis(2-chloroethane)
3 2-chlorophenol
4 1,3-dichlorobenzene
5 1,4-dichlorobenzene
6 1,2-dichlorobenzene
7 bis(2-chloroisopropyl)ether
8 N-nitroso-di-n-propylanine
9 hexachloroethane
10 nitrobenzene
11 3,5,5-triiethy]-2-cyclohexen-l-one
12 2-nitrophenol
13 2,4-diaethylphenol
14 bis(2-chloroethoxy)iethane
15 2,4-dichlorophenol
16 1,2,4-trichlorobenzene
17 naphthalene
18 1,1,2,3,4.4-hexachloro-l,3-butadi ene
19 4-chloro-3-iethylphenol
20 2,4,6-trichlorophenol
21 2-chloronaphthalene
22 diiethylphthalate
23 2,6-dinitrotoluene
24 1,2-dihydroacenaphthylene
25 4-nitrophenol
26 2,4-dinitrotoluene
27 diethylphthalate
28 l-chloro-4-phenoxybenzene
29 9H-fluorene
30 2-iethyl-4,6-dinitrophenol
31 4-broiophenyl-phenylether
32 hexachlorobenzene
33 pentachlorophenol
34 phenanthrene
35 anthracene
36 di-n-butylphthalate
37 fluoranthene
39 pyrene
39 n-butyl benzyl phthalate
40 bis(2-ethylhexyl)phthalate
41 benzo(a)anthracene
42 chrysene
43 di-n-octylphthalate
44 benzo(b)fluoranthene
45 benzo(k)fluoranthene
46 benzo(a)pyrene
47 dibenzo(a,h)anthracene
48 benzolghilperylene
ppb
true
value
100
48.2
30
52
24.8
24.7
38.8
34.8
30
76.5
76.7
50
30
48.6
50
25.3
24.8
49.6
75
25
25.4
40
76.5
19.5
50
73.8
25.1
76.7
51.2
250
41.5
35.7
75
40.2
40
24.9
29.8
60.2
51.3
29.1
73.9
69.9
43.9
40
45.7
24.9
40.7
80.4
CONT.
EH.
(AVE.5/B6)
93.5
95.2
92.9
92.1
98.2
96.8
96.2
97
88.8
95.8
92.7
102
102
97.5
94.8
94.7
94.2
93.4
97.7
109
96.5
98.7
96.8
93.2
106
98.7
92.1
93.9
95.5
108
95.7
93.4
118
94.2
91.5
101
96.7
90.9
96.5
95.5
92.2
92.2
91.6
92.9
89.5
94.8
91.2
89.8
I RECOVERY
HAN
EIT.
(10/84 9A)
44.1
101
110
86.1
93.2
87.7
108
102
80.1
104
98.3
110
99
97.5
106
86.3
96.2
78.3
101
100
93.9
95.9
98.6
99
41.8
101
97.1
95.8
95.7
100
95.5
97.4
67.1
95.4
96
104
100
97.3
99.7
95.1
95.4
99.7
95.1
95.1
91.1
94.5
93.1
87.4
-------
FIGURE 5.
IX)
ro
o:
LJ
o
o
UJ
a:
UJ
o
z
UJ
a:
UJ
u.
u.
a
CONTINUOUS VS. MANUAL A/N EXTRACTION
70
60 -
50
40
30 -
20 -
10 H
-10 -
-20
WP482#1 WP482#3 WP881#1
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47
COMPOUND NUMBER
D CONT.- MANUAL
-------
TABLE 3.
CONTINUOUS VS. MANUAL EXTRACTION
EPA EMSL AUDITSI WP4B2ttl WP4B2«3 WPBBlttl
NO.
COMPOUND
X RECOVERY
CONT. MAN.
TRUE EXT. EXT.
VALUE (AVE.3/B6) (10/84 QA)
PPB
DIFF.
1 PHENOL
3 2-CHLOROPHENOL
1OO
30
93.3
92.9
44.1
110
49.4
-17.1
IB l,l,2f3,4,4-HEXACHLORO-l,3- 49.6
BUTADIENE
25 4-NITROPHENOL
50
93.4
1O6
78.3
41.8
15.1
64.2
33 PENTACHLOROPHENOL
75
118
67. 1
50.9
23
-------
TABLE 4.
CONTINUOUS VS. MANUAL EXTRACTION
EXTRACTION SCHEMES
EPA EMSL AUDITSI WP4B2ttl WP4B2#3 WPBSlttl
NO.
COMPOUND
X RECOVERY
CONT. MAN.
TRUE EXT. EXT.
VALUE (AVE.5/B6) (10/B4 QA)
PPB
DIFF.
1 PHENOL
100
93.3
44.1
49.4
3 2-CHLOROPHENOL
30
92.9
110 -17.1
12 2-NITROPHENOL
50
102
110
-B
13 2,4-DIMETHYLPHENOL
30
102
99
13 2,4-DICHLOROPHENOL
30
94. B
106 -11.2
19 4-CHLORO-3-METHYLPHENOL 75
97.7
101
-3.3
20 2,4,6-TRICHLOROPHENDL
25
1O9
100
25 4-NITROPHENOL
5O
106
41.B
64.2
30 2-METHYL-4.6-
DINITROPHENOL
250
108
1OO
8
33 PENTACHLOROPHENOL
75
118
67. 1
50.9
24
-------
C. Acid/Neutral (A/N) Continuous Extraction vs Base/Neutral (B/N)
Continuous Extraction Schemes
The recoveries of replicate extractions of the priority pollutant
mixture using the Base/Neutral continuous extraction scheme are
listed in Table 5. As indicated, all of the recoveries were within
or just exceeded (compound #25 and #30) EPA Method 625 method
validation criteria with the exception of dimethylphthalate which
was not detected at 40 ppb. A comparison of the A/N and B/N
extraction schemes is presented in Table 6 and Figure 6. The A/N
recoveries are the average of four replicate extractions and the
B/N recoveries are the average of two extractions. The graph is a
plot of the difference in percent recovery (A/N minus B/N). The
A/N scheme was observed to give comparable or improved recoveries.
Significant improvement was observed for the following six compounds
(#9) hexachloroethane (88.8% A/N, 70.7% B/N)
(#18) l,l,2,3,4,4-hexachloro-l,3-butadiene (93.4% A/N, 69% B/N)
(#22) dimethylphthalate (98.7% A/N, n% R/N)
(#27) diethylphthalate (92.1% A/N, 1.7% B/N)
(#36) di-n-butylphthalate (101% A/N, 36% B/N)
(#39) n-butyl benzyl phthalate (96.5% A/N, 32.1 B/N)
The most notable improvement was observed for the phthalate esters.
In Table 7 a comparison of the recoveries obtained for all the
phthalate esters is presented. The generally poor recovery of
phthalate esters by the base/neutral scheme appears to be related
to the size and complexity of the ester side chain. This pattern
25
-------
TABLE 5
BASE NEUTRAL CONTINUOUS EXTRACTION 4/86
EPA EHSL AUDITS: MP4B2I1 HP482I3 HP881I1
I RECOVERY
NO. compound
1 phenol IIIIIIKBASE/N + ACID)
2 l,l-oxybis(2-chloroethane)
3 2-chlorophenol HWIHBflSE/N+ACID)
4 1,3-dichlorobenzene
5 1,4-dichlorobenzene
6 1,2-dichlorobenzene
7 bis(2-chloroisopropyl)ether
8 N-nitroso-di-n-propylaiine
9 hexachloroethane
10 nitrobenzene
11 3,5.5-tri»ethyl-2-cyclohexen-l-one
12 2-nitrophenol
13 2,4-diiethylphenol IIUWIBASE/NtflCID)
14 bis(2-chloroethoxy)«ethane
15 2.4-dichlorophenol
16 1.2,4-trichlorobenzene
17 naphthalene
18 1.1.2.3.4,4-hexachloro-l,3-butadiene
19 4-chloro-3-«ethylphenol tIKBflSE/NtflCID)
20 2,4,6-trichlorophenol
21 2-chloronaphthalene
22 diiethylphthalate
23 2,6-dinitrotoluene
24 1,2-dihydroacenaphthylene
25 4-nitrophenol
26 2,4-dinitrotoluene
27 diethylphthalate
28 l-chloro-4-phenoxybenzene
29 9H-fluorene
30 2-§ethyl-4,6-dinitrophenol
31 4-bro«ophenyl-phenylether
32 hexachlorobenzene
33 pentachlorophenol
34 phenanthrene
35 anthracene
36 di-n-butylphthalate
37 fluoranthene
38 pyrene
39 n-butyl benzyl phthalate
40 bis(2-ethylhexyl)phthalate
41 benzolalanthracene
42 chrysene
43 di-n-octylphthalate
44 benzo(b)fluoranthene
45 benzolklfluoranthene
46 benzola)pyrene
47 dibenzo(a,h)anthracene
48 benzolghiIperylene
ppb
true
value
100
48.2
30
52
24.8
24.7
38.8
34.8
30
76.5
76.7
50
30
48.6
50
25.3
24.8
49.6
75
25
25.4
40
76.5
19.5
50
73.8
25.1
76.7
51.2
250
41.5
35.7
75
40.2
40
24.9
29.8
60.2
51.3
29.1
73.9
69.9
43.9
40
45.7
24.9
40.7
80.4
11
87.9
94.8
91.8
78.3
84.2
82.5
90.3
87
69.8
97.9
94.5
100
89.2
97.7
96.3
84.8
92.5
68.4
109
103
92.4
0
95.4
92.8
110
96.5
2.3
95.9
96.6
101
94.9
91.4
108
93.2
90.6
41.1
95.3
96.5
35
101
93.6
94.9
89.5
90.6
92.1
91.6
91.9
99.2
»2
84.5
97.6
90.8
80.4
86.7
85.1
94.3
90
71.6
98.7
94.9
99.4
88.6
97.5
94.5
83.5
102
69.6
93.2
101
92
0
96.1
93.8
106
96
1
98.6
96.9
104
95.4
94.2
107
96
91.8
30.9
97.4
97.5
29.1
107
95.2
96.3
92.1
93.9
92.7
95
97.7
100
AVERAEE
RECOVERY
86.2
96.2
91.3
79.4
85.5
83.8
92.3
88.5
70.7
98.3
94.7
99.7
88.9
97.6
95.4
83.5
97.3
69
101.1
102
92.2
0
95.8
93.3
108
96.3
1.7
97.3
96.8
102.5
95.2
92.8
107.5
94.6
91.2
36
96.4
97
32.1
104
94.4
95.6
90.8
92.3
92.4
93.3
97.7
99.6
EPA 625
REQUIRED
RECOVERY
16.6-100
42.9-126
36.2-120
16.7-154
37.3-106
48.6-112
62.8-139
13.6-198
55.2-100
54.3-158
46.6-180
45.0-167
41.8-109
49.2-165
52.5-122
57.3-129
35.6-120
37.8-102
40.8-128
52.4-129
64.5-114
D-100
68.1-137
60.1-132
13.0-107
47.5-127
D-100
38.4-145
71.6-108
53-100
64.9-114
7.8-142
38.1-152
65.2-109
43.4-118
8.4-111
42.9-121
69.6-100
D-140
28.9-137
41.8-133
44.1-140
18.6-132
42.0-140
25.2-146
31.7-148
D-200
D-195
-------
TABLE 6.
CONTINUOUS EXTRACTION
ACID NEUTRAL VS. BASE NEUTRAL
EXTRACTION SCHEMES
EPA EHSL AUDITS: HP482I1 WP482I3 HP981I1
1 RECOVERY
NO. coipound
1 phenol
2 I,l-oxybi5(2-chloroethane)
3 2-chlorophenol
4 1,3-dichlorobenzene
5 1,4-dichlorobenzene
6 1,2-dichlorobenzene
7 bis(2-chloroisopropyl)ether
8 N-nitroso-di-n-propylaiine
9 hexachloroethane
10 nitrobenzene
11 3,5,5-triiethyl-2-cyclohexen-l-one
12 2-nitrophenol
13 2,4-diiethylphenol
14 bis(2-chloroethoxy)iethane
15 2,4-dichIorophenol
16 1,2,4-trichlorobenzene
17 naphthalene
18 l,l,2,3,4,4-hexachloro-l,3-butadiene
19 4-chloro-3-iethylphenol
20 2,4,6-trichlorophenol
21 2-chloronaphthalene
22 diiethylphthalate
23 2,6-dinitrotoluene
24 1,2-dihydroacenaphthylene
25 4-nitrophenol
26 2,4-dinitrotoluene
27 diethylphthalate
28 l-chloro-4-phenoxybenzene
29 9H-fluorene
30 2-§ethyl-4,6-dinitrophenol
31 4-broiophenyl-phenylether
32 hexachlorobenzene
33 pentachlorophenol
34 phenanthrene
35 anthracene
36 di-n-butylphthalate
37 fluoranthene
38 pyrene
39 n-butyl benzyl phthalate
40 bis(2-ethylhexyl)phthalate
41 benzo(a)anthracene
42 chrysene
43 di-n-octylphthalate
44 benzolblfluoranthene
45 benzolkHluoranthene
46 benzo(a)pyrene
47 dibenzo(a,h)anthracene
48 benzo(ghi)perylene
ppb
true
value
100
48.2
30
52
24.8
24.7
38.8
34.8
30
76.5
76.7
50
30
48.6
50
25.3
24.8
49.6
75
25
25.4
40
76.5
19.5
50
73.8
25.1
76.7
51.2
250
41.5
35.7
75
40.2
40
24.9
29.8
60.2
51.3
29.1
73.9
69.9
43.9
40
45.7
24.9
40.7
80.4
AC1D/N
EXT.
(AVE.5/86)
93.5
95.2
92.9
92.1
98.2
96.8
96.2
97
88.8
95.8
92.7
102
102
97.5
94.8
94.7
94.2
93.4
97.7
109
96.5
98.7
96.8
93.2
106
98.7
92.1
93.9
95.5
108
95.7
93.4
118
94.2
91.5
101
96.7
90.9
96.5
95.5
92.2
92.2
91.6
92.9
89.5
94.8
91.2
89.8
BASE/N
EXT.
(AVE.4/B6)
86.2
96.2
91.3
79.4
85.5
63.8
92.3
88.5
70.7
98.3
94.7
99.7
88.9
97.6
95.4
83.5
97.3
69
101
102
92.2
0
95.8
93.3
108
96.3
1.7
97.3
96.8
103
95.2
92.8
108
94.6
91.2
36
96.4
97
32.1
104
94.4
95.6
90.8
92.3
92.4
93.3
97.7
99.6
DIFF.
I
7.3
-1
1.6
12.7
12.7
13
3.9
8.5
18.1
-2.5
-2
2.3
13.1
-0.1
-0.6
11.2
-3.1
24.4
-3.3
7
4.3
98.7
1
-0.1
-2
2.4
90.4
-3.4
-1.3
5
0.5
0.6
10
-0.4
0.3
65
0.3
-6.1
64.4
-8.5
-2.2
-3.4
0.8
0.6
-2.9
1.5
-6.5
-9.8
27
-------
FIGURE 6.
ro
CO
DC.
UJ
O
(J
UJ
o:
UJ
o
z
UJ
on
UJ
u_
u.
Q
CONTINUOUS EXTRACTION (A/N VS.B/N)
WP482#1 WP482#2 WP881#1
-10
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47
COMPOUND NUMBER
D A/N-B/N SCHEME
-------
TABLE 7.
CONTINUOUS EXTRACTION
ACID NEUTRAL VS. BASE NEUTRAL
EXTRACTION SCHEMES
PHTHALATE ESTERS
EPA EMSL AUDITS: WP482ttl WP482«3 WPSSltl
NO.
COMPOUND
X RECOVERY
ACID/N BASE/N
TRUE EXT. EXT.
VALUE (AVE.5/86) (AVE.4/86)
PPB
DIFF.
22 DIMETHYLPHTHALATE
40
98.7
O 98.7
27 DIETHYLPHTHALATE
25.1
92.1
1.7 9O.4
36 DI-n-BUTYLPHTHALATE 24.9
39 n-BUTYL BENZYL PHTHALATE 31.3
40 BIS-C2-ETHYLHEXYDPHTHALATE 29.1
101
96.3
93.3
65
32.1 64.4
104 -8.5
43 DI-n-OCTYLPHTHALATE
43.9
91.6
90.8 0.8
29
-------
of recoveries is suggestive of base hydrolysis in which almost
complete cleavage occurs with dimethylphthalate resulting in low
recovery at the elevated pH. Due to steric hindrance, little
hydrolysis occurs for bis(2-ethylhexyl)phthalate. The second
order alkaline hydrolysis rate constants (M-l sec~M listed for
phthalate esters in the literature (8) are consistent with this
mechanism: dimethyl 6.9 x 10~2; bis(2-ethylhexyl) 1.1 x 10~4;
diethyl 1.2 x 10~2; and di-butyl 2.2 x 10'2. The pH of the B/N
extraction scheme was 13.
The recoveries listed for the base/neutral extraction scheme
(Table 5) are the sums of the recoveries obtained from the analysis
of the base/neutral and acid extracts. The only compounds found
in both extracts were phenolics. The distributions of these
compounds between the extracts are listed in Table 8. Significant.
quantities of phenol (8$); 2,4-dimethylphenol (88.9$); and
4-chloro-3-methylphenol (42.9%) were observed to extract (continuous
extraction CE) the B/N phase.
II. Basic Compound Spiking Experiment
Acid/Neutral Continuous Extraction vs. Acid/Neutral Manual Extraction
Another group of compounds spiked into laboratory pure water was termed
"basic compounds". The measured recoveries obtained using acid/neutral
continuous extraction and acid/neutral manual extraction are presented
in Table 9. The continuous extractor gave comparable recoveries
30
-------
TABLE 8.
BASE NEUTRAL CONTINUOUS EXTRACTION 4/B6
ACID COMPOUND RECOVERY PATTERN
EPA EMSL AUDITS: NP482I1 WP482I3 HP881I1
I RECOVERY
NO.
1
3
12
13
15
19
20
25
30
33
COHPOUND
PHENOL
2-CHLOROPHENOL
2-NITROPHENOL
2,4-DIHETHYLPHENOL
2,4-DICHLOROPHENOL
4-CHLORO-3-NETHYLPHENOL
2,4,6-TRICHLOROPHENOL
4-NITROPHENOL
2-NETHYL-4.A-DIN1TROPHENOL
PENTACHLOROPHENOL
TRUE
VALUE
PPB
100
30
50
30
50
75
25
50
250
75
BASE/N
EITRACT
8
2.1
TRACE
88.9
TRACE
42.9
0
0
0
0
ACID
EXTRACT
78.2
89.2
99.7
0
95.4
58.2
102
108
103
108
31
-------
TABLE 9.
CONTINUOUS VS. MANUAL EXTRACTION (OA 10/83)
ACID NEUTRAL + BASE COMBINED
BASIC COMPOUNDS
COMPOUND
* ANILINE
* 4-CHLOROANILINE
t 2-NITROANILINE
« 3-NITROANILINE
t 4-NITROANILINE
t* BENZIDINE
t*«3,3'-DICHLOROBENZIDIN£
CONC.
PPB
1OO
100
100
1OO
1OO
100
10O
75 (BENZENE) *
26-01 -O2 (ME OH) **
3 -O1-02 (MEOH) ***
COMBINED COMBINED
C.E. MANUAL
X X
RECOVERY RECOVERY 8TD.
(AVE.N-4) DEV.
113
89.3
98.1
94.9
82.9
93
94.2
94.7 3.9
97.7 1.8
98.1 0.8
97.3 1.3
95 1.8
64.4 13.4
92.3 7.3
32
-------
for the listed aniline and benzidine compounds with notable improve-
ment measured for benzidine (95% CE and 64.4% manual). The continuous
extractor recoveries reported in this table are the arithmetic sum of
the individual acid/neutral extract and base extract recoveries
presented in Table 10. Two compounds, aniline and benzidine, were
found to extract significantly in the base extract after completion
of the acid/neutral extraction. Benzidine was detected only in the
base extract and 85.2% of the aniline was detected in this fraction.
These proved to be the only target compounds tested in this study to
be basic to the extent that they were not completely extracted by the
first (acid/neutral) extraction.
The pKa for aniline is 4.63 and the pKa^ and pKaj> for benzidine are
4.66 and 3.57, respectively (9). Even though the aniline would be
expected to be present at 99.98% as the hydrophi lie-charged species
during the acid/neutral extraction (pH approximately 1.0), because of
the continuous shifting of equilibria in the extractor toward the
solvent, 28.1% of the aniline was recovered with the acidic extraction.
With this acidic extraction, benzidine would be distributed between
the singularly charged and doubly charged hydrophi lie species and was
not measurably extracted from the aqueous phase. Both aniline and
benzidine have been dropped from the EPA Superfund target analyte
list (10). Benzidine is a priority pollutant and remains part of EPA
Method 625.
A similar spiking experiment using the CE technique was repeated for
aniline (100 ug/L) and benzidine (100 ug/L) at pH 7.0 (neutral
extraction). This was followed by a separate base extraction (pH>ll)
33
-------
TABLE 10.
ACID NEUTRAL CONTINUOUS EXTRACTION
BASIC COMPOUNDS
(2/86)
EPA/RTP C075 (BENZENE)
EPA/RTP EC26-01-02 (MEOH)
EPA/RTP EC5-01-02 (MEOH)
*
**
***
COMPOUND
* ANILINE (HSL)
* 4-CHLOROANILINE (HSL)
* 2-NITROANILINE (HSL)
* 3-NITROAN1LINE (HSL)
* 4-NITRQANILINE (HSL)
** BENZIDINE
***3,3"-DICHLOROBENZIDINE
CONC.
PPB
100
1 00
100
100
1 00
1 00
1 00
•/.
RECOVERY
A/N
28.
89.
98.
94.
82.
94.
1
5
1
6
9
0
*?
7.
RECOVERY
BASE
85. 2
O
0
0
0
95
0
34
-------
with the two extract concentrates analyzed separately. These compounds
were only detected in the neutral extract (aniline 91.9^ recovered,
benzidine 99.9% recovered). It was concluded that basic pH conditions
were not necessary for the recovery of these compounds. However,
aniline and benzidine are weak bases relative to alkylamines, certain
pyridines and numerous other organic bases. The basic extraction
following the A/N was desirable despite the increased potential for
emulsion formation and chemical reactions, to provide a broad pH
extraction range. This assured the recovery of the full gamut of
organic compounds potentially present in environmental samples.
III. Additional Compounds Spiking Experiment
Acid/Neutral Continuous Extraction vs Acid/Neutral Manual Extraction
Thirteen additional target compounds, not included in the priority
pollutant or basic compound mixtures, were spiked separately into
laboratory pure water. The recoveries obtained for these analyses,
each performed in duplicate, are listed in Table 11. The continuous
extractor resulted in 99.6% recovery of N-nitrosodimethylamine. This
was the most volatile of all target compounds. Its chromatographic
retention time was very near that of the solvent front. Hexachloro-
cyclopentadiene, a heat labile compound, gave an average recovery of
102% with continuous extraction. All of the "additional compounds"
tested were found _tiD extract totally into the A/N extract—none were
detected in the base extract. The results of this experiment indicated
that, even after 24 hours of extraction with boiling methylene chloride
35
-------
TABLE 11.
CONTINUOUS VS. MANUAL EXTRACTION (5/86)
ACID NEUTRAL
ADDITIONAL COMPOUNDS
EPA/RTP (MEOH) t
CHEM SERVICE INC.(NEAT MATERIAL INTO MEOH) t*
COMPOUND
BENZYL ALCOHOL (H8L)
-------
at 40°C and a sample temperature (heated slightly by the process) of
approximately 29°C, these fragile compounds were little affected.
Benzoic acid proved to be the compound with the poorest extraction
efficiency of all the target compounds tested. The average continuous
extractor efficiency was 30.5% and was quite erratic with a standard
deviation of 18 (N=2), Table 12. Similar problems and even poorer
recoveries were encountered with manual extraction of benzoic acid,
Table 11. Benzoic acid is not a priority pollutant but is a Superfund
HSL compound.
IV. Pesticides Spiking Experiment
Acid/Neutral Continuous Extraction
The final category of compounds tested as spikes into laboratory pure
water were sixteen priority pollutant pesticides. A single analysis
was performed at 50 ug/L each and the recoveries obtained are included
in Table 13. This spiking level proved quite low for electron impact
mass spectrometry employing single mass quantisation routines. Despite
low sensitivity these compounds gave recoveries ranging from 83.7 to
104% and were all within recoveries required by EPA Method 625 (CFR -
Table 6 - QC Acceptance Criteria (1)).
V. Environmental Samples
A. Sewage Treatment Plant Influent: Acid/Neutral Continuous
Extraction vs. Acid/Neutral Manual Extraction
The reconstructed ion chromatograms (RIO presented in Figure 7
37
-------
TABLE 12.
ACID NEUTRAL CONTINUOUS EXTRACTION (5/86)
ADDITIONAL COMPOUNDS
EPA/RTP (MEOH) t
CHEM SERVICE INC.(NEAT MATERIAL INTO MEOH) *t
ACID/N ACID/N ACID/N
CONG XXX
COMPOUND PPB REC. REC. REC.
•1 #2 AVE.
BENZYL ALCOHOL (HSL) ** SO 86.2 101 93.6
DIBENZOFURAN (HSL) ** SO 83.7 93.3 89.6
N-NITROSODIMETHYLAMINE t SO 98.1 101 99.6
2-METHYLNAPHTHALENE (HSL) t* 12S 1O4 1OO 102
HEXACHLOROCYCLOPENTADIENE * SO 103 10O 101.3
ACENAPHTHYLENE * SO 9O.8 83.9 88.4
INDENO(1,2,3-CD)PYRENE t SO 98.4 90.3 94.3
2-METHYLPHENOL (HSL)t 1OO 86.3 1O2 94.3
4-METHYLPHENOL (HSL) • 1OO 94.2 10O 97.1
2,4,3-TRICHLOROPHENOL (HSL) tt 1OO 92.9 98.9 93.9
BENZOIC ACID (HSL) tt 10O 17.7 43.2 30.3
2,4-DINITROPHENOL * 1OO 110 123 117.3
N-NITROSODIPHENYLAMINE tt SO 87.3 93.1 9O.3
38
-------
TABLE 13.
ACJD NEUTRAL. CONTINUOUS EXTRACTION PESTICIDES (3/86)
E P A / R "I' l-;' S "I" A N D A R D C 0 4 3 (' \ 01... U E N E •- hi E X A M E)
MO,.
1
2
'•-•
4
5
6
7
8
9
.1 0
:l J
:i2
13
;l 4
15
.1 6
COMPOUND TRUE
VALUE PPB
AL.PHA-BHi: 50
BETA-BEIC 50
GAM !vl A - B H C. (LI N D A N E ) 5 0
DEL "I A-'fiHC 50
HE FT A CUE OR 50
A!.. DRUM 50
HE FT A OIL OR EPOX IDE. 50
EIMDUSULEAN I (ALPHA) 50
4, 4 ;' -••• DDE 50
DIELDRIN 5u
EN DRUM 50
4 , t\ [' --DDD 50
E N D 0 S LI I ... E A N 31 l B E T A ) 50
EN DRUM ALDEHYDE 50
4. 4" -"-DDT 50
E N D 0 B U 1 ... F A N C Y C L I C S U L. F A T E 5 0
EPA 625 *
7. REQUIRED "/.
R EEC 0 V E F :< Y R E C 0 VERY
97.7
95.5
98.. 2
95.7 24 149
95 ,,6 D--192
101 D-166
97.8 2 6 -15 5
92., 9
95., 3 4-- 136
97 2 9-- 136
104
92.:l D-145
88. .1
85,. 6 D--.209
88.. 1 U-203
83.. 7 D 107
*. 4 0 C F R P P, R T 1 3 6 , V 0 L . 4 9, N 0. 4 9 , F R I D A Y , 0 C "I".. 2 6 , :l 9 8'
D- DETECT ION LIMIT
39
-------
188.0-1
RIC
04/15/86 10:16:00
SAMPLE: C.E. EXPERIMENT
RANGE: G 1,3888 LABEL: N 0, 4.0 BASF: U 20, 3
CONTINUOUS A/N EXTRACTION SCHEME:
DATA: RCE31402 #1>MAN31482
CALI: CALTEST #1 SCANS 660 TO 3000
RIC I
67.0n
RICjl
£73
cr
TO
OO O
m o
CT)
m
—I c->
70 —I
m m
m o
—• O
Z CD
m oo
—t O
1668
13:20
1506
20:80
2080
26:40
2500
33:28
3000 SCAN
40:00 TIME
-------
were obtained from influent to a waste treatment plant in Virginia.
The sample was analyzed as part of EPA's Pre-Treatment Program.
The top RIC was obtained after continuous extraction and the
bottom graph was from manual extraction. The target compounds
detected are listed in Table 14. The CE technique resulted in
good agreement with the manual extraction except for bis-
(2-ethylhexylJphthalate in which significantly more was recovered
by CE. This compound had been observed to extract equally well in
laboratory pure water spiking experiments: 95.5% recovery via CE
and 104% manually. This phthalate compound is a common laboratory
contaminant, however reagent blanks analyzed with these extractions
were free of this compound. Further, the high sample concentration
recovered by CE (45.7 ppb) far exceeds any trace (0.1 ppb) level
contamination observed during this work.
The non-target analytes (those for which standards were not readily
available) and tentatively identified compounds detected in this
sample by these extraction schemes are presented in Figure 8.
These compounds represent a broad range of aromatic and aliphatic
hydrocarbons for which the CE recovery was determined to equal or
exceed that observed by separatory funnel extraction. The
concentrations are reported as "estimated" in that a response
factor of 1.0 has been assumed for each compound relative to the
closest eluting internal standard. The manual extraction of this
sample resulted in a thick emulsion (heaviest at pH>ll).
Centrifugation was required after each two minute shaking period
with methylene chloride in order to break the emulsion.
41
-------
TABLE 14.
SEWAGE TREATMENT PLANT INFLUENT
ACID/NEUTRAL EXTRACTION 500 ML
NPDES 24HR COMPOSITE. SAMPLE 86031402
TARGET COMPOUNDS
COMPOUND
1,4-DICHLOROBENZENE
1 ., 2-DICHLOROBENZENE
2-METHYLNAPHTHALENE
DIETHYLPHTHALATE
PHENANTHRENE
BI5<2-ETHYLHEXYL>-
PHTHALATE
D10CTYLPHTHALATE
CONC. PPB
CONT.
EXT.
4-15-86
0.5J
0.6J
0.2J
1.8J
0.5J
45.7
MAN.
EXT.
4-15-86
0.3J
0.5J
ND
1.6J
0.4J
14.2
0.8J
0.8J
42
-------
FIGURE 8.
SEWAGE TREATMENT PLANT INFLUENT
ACID/NEUTRAL EXTRACTION SCHEME
m
0.
0.
u
o
(J
D
u
111
11 13 15 17 19 21 22 25 27 29
3579
D CONTINUOUS EXT.
MANUAL OCT.
NO.
TENTATIVE IDENTIFICATION
COMPOUND
NO.
COMPOUND
1 4-METHYL-2-PROPYL-1-PENTANOL 16
2 2,3,6-TRIMETHYLHEPTANE 17
3 2,3,7-TRIMETHYLOCTANE 18
4 1,2,4-TRIMETHYLBENZENE 19
3 (1-METHYLETHYL)BENZENE 20
6 DECANE 21
7 5-ETHYL-2-METHYLHEPTANE 22
B 1,2,4-TRIMETHYLBENZENE 23
9 4,6,8-TRIMETHYL-l-NONENE 24
10 DECAHYDRONAPHTHALENE 25
11 3-ETHYL-2,7-DIMETHYLOCTANE 26
12 UNDECANE 27
13 3,7-DIMETHYLNONANE 28
14 1,2,4,5-TETRAMETHYLBENZENE 29
13 2-PROPENYLCYCLOHEXANE
3-METHYLUNDECANE
6-METHYLDODECANE
2,3,7-TRIMETHYLOCTANE
TRIDECANE
TETRADECANE
4,7-DIMETHYLUNDECANE
3,7-DIMETHYLUNDECANE
4,7-DIMETHYLUNDECANE
DODECANOIC ACID
HEXADECANE
4-(1,1,3,3-TETRAMETHYLBUTYL)PHENOL
3,6-DIMETHYLUNDECANE
4,7-DIMETHYLUNDECANE
UNKNOWN
43
-------
B. River Water from an Industrial Spill:
Acid/Neutral Continuous Extraction vs. Acid/Neutral Manual Extraction
The results of target compounds presented in Table 15 represent the
analysis of estuarine river water after a spill by a mothball
manufacturer. As indicated by the analysis, this was a chlorinated
benzene type of insecticide and extensive quantities of dichloro-
and trichlorobenzene isomers were measured. The table indicates
close agreement between the results of the two extraction procedures
with the exception of 2-chlorophenol. Spikes of this compound into
reagent water had given comparable recovery (92.9% by CE and 110%
recovery using manual extraction). The ten fold higher value by
CE in this sample suggests possible matrix interference for the
manual extraction or a positive interference with continuous
extraction. The mass spectrum, chromatographic peak shape and
relative retention time were clearly indicative of 2-chlorophenol
and did not indicate the possibility of a co-eluting compound or
false positive identification. A possible mechanism for the
formation of this compound under these extraction conditions is
unclear and unlikely. Spikes of fifty ppb (ug/L) of 1,4-dichloro-
benzene and 1,2,4-trichlorobenzene into seventeen industrial waste
and superfund landfill samples have resulted in average recoveries
of 71.8% (HI.9) and 73.9% (_+12.7) respectively by continuous acid
neutral extraction. The non-target compounds extracted from this
sample matrix by these techniques are presented in Figure 9. As
indicated, this sample contained significant quantities of
chlorinated benzenes that extracted comparably by both extraction
44
-------
TABLE 15.
RIVER WATER FROM AN INDUSTRIAL BRILL-
AC ID/NEUTRAL EXTRACTION SCHEME 5OO ML
MOTHBALL MANUFACTURER
TARSET COMPOUNDS
COMPOUND
PHENOL
2-CHLOROPHENOL
1,2-DICHLOROBENZENE
1,4-DICHLOROBENZENE (35m/z)
1,2-DICHLOROBENZENE (35m/z)
2-METHYLPHENOL HSL
NITROBENZENE
2,4-DIMETHYLPHENOL
2,4-DICHLOROPHENOL
1f 2,4-TRICHLOROBENZENE
CONC. PPB
CONT. MAN.
EXT. EXT.
A-02-B6 6-02-86
44
340
46
1950
270
12J
33
31
3.BJ
390
46
24
46
1700
240
10J
30
30
1.4J
320
45
-------
FIGURE 9.
RIVER WATER FROM INDUSTRIAL SPILL
m
Q.
n
u
2
0
o
w
LJ
10 -
ACID/NEUTRAL EXTRACTION SCHEME
t 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
COMPOUND NO.
O CONTINUOUS EXT.
+ MANUAL EXT.
NO.
1
2
3
4
5
6
7
B
TENTATIVE IDENTIFICATIONS
COMPOUND
(1-METHYLETHYL)BENZENE
(METHYLETHYL)BENZENE ISOMER
ETHYL-METHYLBENZENE ISOMER
METHYLPHENOL ISOMER
NO.
COMPOUND
9 1,2,3,3-TETRACHLOROBENZENE
1O METHYL-ETHYLPROPANOIC ACID ISOMER
11 TETRACHLOROBENZENE ISOMER
12 1H-BENZOTRIAZOLE
1-CHLORO-4-(CHLOROMETHYL)BENZENE 13 PENTACHLOROBENZENE
UNKNOWN 14 TETRADECANOIC ACID
1,3,5-TRICHLOROBENZENE 15 HEXADECANOIC ACID
BUTAND1C ACID.2-PROPENYL ESTER 16 1-(ETHENYLOXY)OCTADECANE
17 UNKNOWN
46
-------
schemes. One significant peak was detected by the CE analysis
and not by the manual extraction (compound #6). It was not
identified because of a poor spectral match with the compounds in
the EPA-NIH mass spectral library. This compound had a base peak
of 43 m/z and a mass spectrum indicative of an aliphatic hydrocarbon.
C. Ground Water from Superfund Test Wells:
Acid/Neutral Continuous Extraction vs. Acid/Neutral Manual Extraction
Samples from two test wells at a Superfund site in Pennsylvania
were extracted and analyzed. The concentrations measured for the
target compounds of the more highly comtaminated Well #2 are
presented in Table 16. The data indicate significant benzyl
alcohol and methyphenol contamination. The CE extraction scheme
resulted in target compound concentrations that equaled or exceeded
all target compounds detected by manual extraction. The relatively
poor benzoic acid recovery by manual extraction was consistent
with spiking results in laboratory pure water. The recovery of
benzyl alcohol by manual extraction, also low relative to CE in
this sample, had not been tested with laboratory pure water spikes.
This sample from Well #2 was extracted as 500 ml of sample (manual
and CE) diluted to 1 liter with laboratory pure water. The base
peak ions for benzyl alcohol and benzoic acid saturated the electron
multiplier and quantisation was performed using an alternate (less
intense) ion. This technique afforded a greater dynamic range and
allowed the determination of compounds present at trace levels as
well as those present in macro amounts by a single GC/MS analysis.
47
-------
TABLE 16.
8ROUND WATER (8UPERFUND)
ACID/NEUTRAL EXTRACTION SCHEME
ENFORCEMENT-REMEDIAL TEST WELL «2
TARGET COMPOUNDS 6-06-86
CONC. PP6
COMPOUND
PHENOL
1,4-DICHLOROBENZENE
BENZYL ALCOHOL
1,2-DICHLOROBENZENE
2-METHYLPHENOL
4-METHYLPHENOL
2,4-DIMETHYLPHENOL
BENZOIC ACID
2,4-D1CHLOROPHENOL
NAPHTHALENE
PHENANTHRENE
BUTYLBENZYL-
PHTHALATE
DI-n-OCTYL
PHTHALATE
CONT.
EXT.
72
6.5J
4400
10J
340
620
114
1240
1.1J
13J
0.1J
55
MAN.
EXT.
25
6.2J
1100
10J
450
340
92
316
0.9J
12J
O. U
45
4.7J
1.2J
48
-------
The tentatively identified compounds extracted from this test well
are presented in Figures 10 and 11. The compounds are predominantly
alkyl substituted aromatics. The recovery of N,N-dimethylbenzenamine
followed the pattern established for 4,4'-diafninobiphenyl (benzidine)
in lab pure water: much greater quantities were recovered by the
continuous extractor (440 ug/L CE and 100 ug/L manual). The
recoveries for 3-methylbenzoic acid were much closer (29 ug/L CE and
38 ug/L manual) than those for benzoic acid (1240 ug/L CE and 318
ug/L manual). The benzoic acid recoveries for this sample were
similar to those obtained from spikes into laboratory pure water
(30.5% CE recovery and 0.1% manual recovery). The phenol recovery
was approximately three times larger by continuous extraction (72
ug/L CE and 25 ug/L manual). Test Well #5 was far less contaminated.
The target compounds were present in trace concentrations, except
for bis(2-ethythexyl )phthalate. Extraction efficiencies (Table 17)
were comparable by both extraction schemes. The tentatively
identified compounds in this well water (Figure 12) ranged 10 to
200 fold lower in concentration than for test Well #2. The
agreement in recoveries obtained using the two extraction schemes
was excellent with the exception of: dihydro-2(3H)-furanone (5.6
ug/L CE and not detected by manual extraction); 4,7-dimethyl-undecane
(11 ug/L CE and 20 ug/L manual) and (entry #20) unknown hydrocarbon
(17.0 ug/L CE and not detected by manual extraction).
D. Industrial Effluents:
Acid/Neutral Continuous Extraction vs. Acid/Neutral Manual Extraction
The final environmental matrix studies were from two metal finishing
49
-------
FIGURE 10.
ID
0.
Q.
u
o
u
600
500 -
GROUND WATER (SUPERFUND) WELL #2
ACID/NEUTRAL EXTRACTION SCHEME
9 10 11 12 13 14 15 16
CONTINUOUS EXT.
+ MANUAL EXT.
TENTATIVE IDENTIFICATIONS
NO. COMPOUND NO.
1 1,2-DIMETHYLBENZENE 9
2 1,3-DIMETHYLBENZENE 1O
3 1,4-DICHLOROBUTANE 11
4 DIETHYLDISULFIDE 12
5 1-METHYLETHYLBENZENE 13
6 PROPYLBENZENE 14
7 l-ETHYL-4-METHYLBENZENE 15
B 1,2,4-TRIMETHYLBENZENE 16
COMPOUND
l-ETHYL-2-METHYLBENZENE
1,2,4-TRIMETHYLBENZENE
(2-METHYLPROPYD BENZENE
2-ETHYL-l-HEXANOL
l-METHYL-3-(1-METHYLETHYL)BENZENE
4-ETHYL-1,2-DIMETHYLBENZENE
N,N-DIMETHYLBENZEAMINE
2,3-DIMETHYLPHENOL
50
-------
FIGURE 11.
CD
Q.
Q.
d
o
o
GROUND WATER (SUPERFUND) WELL £2
ACID/NBJTRAL EXTRACTION SCHEME
240 -i 1
17 16 19 20 21 22 23 24 25 26 27 28 29 30 31 32
COMPOUiO NO.
D CONTWUOUS OCT.
+ MANUAL EXT.
TENTATIVE IDENTIFICATIONS
NO. COMPOUND NO.
17 2-ETHYLHEXANOIC ACID 25
18 PHOSPHORIC ACID, TRIETHYL ESTER 26
19 2-ETHYLPHENOL 27
20 BENZENEACTONITRILE 28
21 2,2,4-TRIMETHYL-1,3-PENTANEDIOL 29
22 1,7,7-TRIMETHYL-BICYCLO<2.2. D- 3O
HEPTAN-2-ONE
31
23 3,4-DIMETHYLPHENOL
24 BENZENEACETIC ACID
32
COMPOUND
3-METHYLBENZOIC ACID
UNKNOWN HYDROCARBON
UNKNOWN HYDROCARBON
1,3-ISOBENZOFURANDIONE
BENZAMIDE
1(3H)-ISOBENZOFURANONE
4-(1,1,3,3-TETRAMETHYLBUTYL)
PHENOL
UNKNOWN HYDROCARBON
51
-------
TABLE 17.
GROUND WATER (BUPERFUND)
ACID/NEUTRAL EXTRACTION SCHEME
ENFORCEMENT-REMEDIAL TEST WELL
TARGET COMPOUNDS 6-O6-B6
CONC. PPB
COMPOUND
CONT.
EXT.
MAN.
EXT.
1,4-DICHLOROBENZENE 0.9J
1,2-DICHLOROBENZENE 0.5J
2-METHYLPHENOL 1.2J
BENZOIC ACID 0.2J
2-CHLOROANILINE 1.1J
BIS(2-ETHYLHEXYL>- 45
PHTHALATE
O.6J
0.3J
l.OJ
ND
O.BJ
34
52
-------
FIGURE 12.
GROUND WATER (SUPERFUND) WELL #5
ACID/NEUTRAL EXTRACTION SCHEME
CD
0.
0.
U
o
O
in
LJ
13 15 17 19 21 23 25 27
NO. TENTATIVE IDENTIFICATIONS NO.
1 1,2-DIMETHYLBENZENE 15
2 1,4-DICHLOROBUTANE 16
3 DIHYDRO-2(3H)-FURANONE . 17
4 2-CHLOROPYRIDINE 18
5 2-ETHYL-l-HEXANOL 19
6 DIMETHYLBENZENE METHANOL 20
7 2-EHTYLHEXANOIC ACID 21
8 2-(2-BUTOXYETHOXY)ETHANOL 22
9 TETRAMETHYLTHIOUREA 23
10 2,2,4,4-TETRAMETHYLPENTANE 24
nl BENZOTHIAZOLE 25
12 N-METHYL-N-PHENYLACETAMIDE 26
13 3,7-DIMETHYLNONANE 27
14 1,1'(1,3-PHENYLENE)BIS-ETHANONE
•f MANUAL EXT.
COMPOUND
1,1'-(1,4-PHENYLENE)BIS-ETHANONE
2,4,6-TRIMETHYLOCTANE
2,6,11-TRIMETHYLDODECANE
4,7-DIMETHYLUNDECANE
2,7,10-TRIMETHYLDODECANE
UNKNOWN HYDROCARBON
UNKNOWN HYDROCARBON
2,6,11-TRIMETHYLDODECANE
HEXADECANE
4,7-DIMETHYLUNDECANE
UNKNOWN HYDROCARBON
HEPTADECANE
2,7,10-TRIMETHYLDODECANE
53
-------
companies in Pennsylvania. In the first, designated 860227-12, the
trace level target compounds detected (phenolics and polynuclear
aromatics) were extracted to the same extent by both techniques as
indicated by the first and third columns of Table 18. The manual
extraction was performed in duplicate. The benzoic acid present in
this aqueous sample matrix, which contained primarily alcohols,
aldehydes and ketones (Figure 13) was extracted to a greater extent
by the continuous extactor (1300 ug/L CE and 775 ug/L manual). As
indicated in Table 18, the acid/neutral and base extracts from the
continuous extraction were analyzed separately and no target
compounds were detected in the base extract. However, the tentatively
identified compounds 3-phenyl-2-butanone (3.2 ug/L); 4-methoxy-
benzaldehyde (14 ug/L); and 1,2-dimethoxyethylbenzene (3.6 ug/L)
were detected in the base CE extract (Table 19). The first two
compounds may represent trace carry over since much higher
concentrations were measured in the acid/neutral CE extract (170
ug/L and 630 ug/L respectively). The 1,2-dimethoxyethylbenzene
measured was at trace levels and may have also been recovered in
the acid neutral extract but been below the level of GC/MS detection.
A second industrial effluent was collected from a different metal
plating company. The sample was milky-white in color and required
repeated centrifugation to break the emulsions formed during the
manual extraction. The single target compound detected was henzoic
acid which was recovered in trace quantity only from the continuous
extractor. The most predominant tentatively identified compound
was 3-octadecene. The close agreement of the two extraction
schemes is evident in Figure 14.
54
-------
TABLE 18.
INDUSTRIAL EFFLUENT
ACID/NEUTRAL EXTRACTION
SAMPLE 860227-12
TAROET COMPOUNDS 3-3-86
COMPOUND
CDNT. CONT.
A/N BASE
CONC. PPB
AVE.
MAN.
A/N+BASE
MAN.
• 1
MAN.
•2
PHENOL
2-CHLOROPHENOL
BENZOIC ACID
NAPHTHALENE
6.1J
3.2J
13OO
12
2-METHYLNAPHTHALENE 2.7J
PHENANTHRENE
0.3J
ND
ND
ND
ND
ND
ND
1.2J
ND
773
8.4
3.9
0. 1J
2.4J
ND
9.7J
4.7J
0.2J
ND
ND
770 780
7J
3J
ND
55
-------
FIGURE 13.
m
a.
a.
u
z
o
u
700
600 -
500 -
400 -
300 -
200 -
100 -
INDUSTRIAL EFFLUENT
ACID/NEUTRAL EXTRACTION
CONTWUOUS EXT.
4 5
COMPOUND NO.
6 7
+ MANUAL EXT.
TENTATIVE IDENTIFICATIONS
NO. COMPOUND
1 UNDECANE
2 2-CHLOROBENZALDEHYDE
3 2-CHLDROBENZENE METHANOL
4 3-PHENYL-2-BUTANONE
5 3-METHOXYBENZALDEHYDE
6 4-METHOXYBENZALDEHYDE
7 2-BUTOXYETHANOL
8 3,4-DIMETHOXYBENZENE METHANOL
9 1,2-DIMETHOXYETHYLBENZENE
56
-------
TABLE 19.
INDUSTRIAL EFFLUENT
ACID/NEUTRAL EXTRACTION
SAMPLE B60227-12
TENTATIVE IDENTIFICATIONS 3-3-B6
ESTIMATED CONC. PPB
NO.
COMPOUND
CONT. CONT. AVE. MAN.
EXT. EXT. EXT. MAN. MAN.
A/N BASE A/N+BASE «1 #2
1 UNDECANE
ISO
ND
170
140
200
2-CHLOROBENZALDEHYDE
82
ND
72.3
66
3 2-CHLOROBENZENE -
METHANOL
230
ND
205
240
170
4 3-PHENYL-2-BUTANONE
170
3.2
140
160
120
5 3-METHOXYBENZALDEHYDE 23O
ND
210
250
170
6 4-METHOXYBENZALDEHYDE 630
14
620
650
590
7 2-BUTOXYETHANOL
130
ND
125
160
90
0 3,4-DIMETHOXYBENZENE-
METHANOL
100
ND
96
130
62
9 1,2-DIMETHOXYETHYL-
BENZENE
ND
3.6
7.5
10
57
-------
FIGURE 14.
m
Q.
Q.
Z T)
O c
o 8
METAL PLATING (INDUSTRIAL EFFLUENT)
ACID/NEUTRAL EXTRACTION SCHEME
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
D COKT1NUOUS EXT.
+ MANUAL EXT.
NO.
TENTATIVE IDENTIFICATIONS
COMPOUND NO.
1 2-BUTOXYETHANOL 11
2 l-HYDROXY-2-PROPANONE 12
3 l,3-DIHYDRO-2H-INDOL-2-ONE 13
4 l,2-DIHYDRO-2H-INDOL-2-ONE 14
5 2,4, 6-TRIMETHYLOCTANE 13
6 3,7-DIMETHYLUNDECANE 16
7 4,7-DIMETHYLUNDECANE 17
8 HEXADECANOIC ACID IB
9 4,7-DIMETHYLUNDECANE 19
10 3-OCTADECENE
COMPOUND
3,8-DIMETHYLDECANE
HEXADECANE
UNKNOWN
2,6,11-TRIMETHYLDODECANE
HEPTACOSANE
2,7,10-TRIMETHYLDODECANE
NONADECANE
2,6,10-TRIMETHYLDODECANE
UNKNOWN HYDROCARBON
58
-------
VI. Partition Experiment
The recoveries for the priority pollutant mixture obtained from a single
350 mL solvent pass using a stopcock fitted continuous extractor are
presented in Table 20. For the purposes of this paper, a "partition
ratio" has been defined as the weight of material in the solvent phase
relative to the weight of the material in the aqueous phase. This was
calculated as:
Partition Ratio = ng in solvent phase = ng measured in solvent phase
ng in aqueous phase (ng measured in unextracted
reference solution - ng
measured in solvent phase)
The partition ratios ranged from 0.1 for benzo(a)anthracene to 26.5 for
pentachlorophenol. The process occurring in the extractor is complicated.
Droplets of dense solvent fall rapidly through the sample and a steady
state distribution of analytes between the two phases may not be
occurring. The extracting solvent is freshly distilled, shifting the
analyte distribution in favor of the clean solvent. The solvent/sample
interface at the bottom of the extractor would also be expected to be
involved in the partition process. As a result of this complexity,
the continuous extraction process is difficult to describe in terms
of discrete partitions or equilibria. The partition ratios measured
represent the extent of extraction that had occurred with 350 mL of
CH^CL? passing through the spiked reagent water in 53 minutes at 29°C.
These results indicate that a great deal of material had .extracted
within one hour. Interestingly, even though the late eluting
compounds, benzofa)anthracene through benzo(ghiIperylene, had the
lowest partition ratios, the CE recoveries for these compounds after
24 hours were all in excess of 89% (Priority Pollutant Cocktail
Spiking Experiment, Table 1.)
-------
TABLE 20.
ACID NEUTRAL CONTINUOUS EXTINCTION 1PASS
EPA EHSL AUDITS: HP482II MP482I3 HP881I1
1 phenol
2 l,l-oxybis(2-chloroethane)
3 2-chlorophenol
4 1,3-dichlorobenzene
5 1,4-dichlorobenzene
4 1,2-dichlorobenzene
7 bis(2-chloroisopropyl)ether
8 N-nitroso-di-n-propylaiine
9 hexachloroethane
10 nitrobenzene
11 3,5,5-tri«ethyl-2-cyclohexen-l-one
12 2-nitrophenol
13 2,4-di»ethylphenol
14 bis(2-chloroethoxy)iethane
15 2,4-dichlorophenol
16 1,2,4-trichlorobenzene
17 naphthalene
18 l,l,2,3,4,4-hexjchloro-l,3-butadiene
19 4-chloro-3-iethylphenol
20 2,4,6-trichlorophenol
21 2-chloronaphthalene
22 dicethylphthalate
23 2,6-dinitrotoluene
24 1,2-dihydroacenaphthyJene
25 4-nitrophenol
26 2,4-dinitrotoluene
27 diethylphthalate
28 l-chloro-4-phenoxybenzene
29 9H-fluorene
30 2-nethyl-4,6-dinitrophenol
31 4-broiophenyl-phenylether
32 hexachlorobenzene
33 pentachlorophenol
34 phenanthrene
35 anthracene
36 di-n-butylphthalate
37 fluoranthene
38 pyrene
39 n-butyl benzyl phthalate
40 bis(2-ethylhexyl)phthalate
41 benzo(a)anthracene
42 chrysene
43 di-n-octylphthalate
44 benzolbHluoranthene
45 benzolklfluoranthene
46 benzo(a)pyrene
47 dibenro(a,h)anthracene
48 benzolghilperylene
EXP. 5/86
MEASURED
ng
Spiked
95.8
45.9
27.4
46.7
21.1
22.1
35.4
21.9
26.2
69.8
76.4
43.3
21.3
44.3
44.7
21.8
23.5
43.3
69.8
18.7
23.5
40.8
75.5
10.0
50.7
66.5
24.2
78.2
45.2
245.0
37.1
30.3
50.4
36.9
30.8
22.7
29.1
54.6
47.3
25.0
55.8
67.3
39.5
38.7
35.9
20.5
45.3
74.6
ng
solvent
49.7
37.0
21.7
31.3
16.7
16.8
29.5
13.6
18.5
55.8
62.8
40.3
16.2
36.9
39.2
17.6
18.9
31.0
61.1
17.7
18.2
32.0
42.4
8.2
29.0
55.7
20.2
59.8
35.3
241.3
28.9
18.8
48.5
30.2
30.0
18.5
21.2
36.0
34.4
5.5
7.1
21.9
6.7
11.2
7.5
5.5
6.3
10.8
ng
aqueous
46.1
8.9
5.7
15.4
4.4
5.3
5.9
8.3
7.7
14.0
13.6
3.0
5.1
7.4
5.5
4.2
4.6
12.3
8.7
1.0
5.3
8.8
13.1
1.8
21.7
10.8
4.0
18.4
9.9
3.7
8.2
11.5
1.9
6.7
0.8
4.2
7.9
18.6
12.9
19.5
48.7
45.4
32.8
27.5
28.4
15.0
39.0
63.8
partition
ratio
1.1
4.2
3.8
2.0
3.B
3.2
5.0
1.6
2.4
4,0
4.6
13.4
3.2
5.0
7.1
4.2
4.1
2.5
7.0
17.7
3.4
3.6
4.B
4.6
1.3
5.2
5.1
3.3
3.6
65.2
3.5
1.6
25.5
4.5
37.5
4.4
2.7
1.9
2.7
0.3
0.1
0.5
0.2
0.4
0.3
0.4
0.2
0.2
60
-------
Conclusions
The acid/neutral continuous extraction scheme is effective, elegant, and
labor saving. Its effectiveness derives from both its acid/neutral and
continuous aspects. The acid/neutral continuous extraction scheme resulted
in recoveries of priority pollutant compounds that satisfied the method
validation requirements of EPA Method 625, with the exception of 2-methyl-
4,6-dinitrophenol which was recovered at 108% (53-100% required). The
continuous extraction scheme provided a safer mode of extraction since the
analyst was less exposed to methylene chloride and hazardous sample
constituents. In addition the continuous mode of extraction: improved the
recoveries of phenol, 4-nitrophenol, pentachlorophenol and benzoic acid.
The acid/neutral scheme as opposed to the Method 625 base/neutral extraction
was found to greatly improve the recovery of dimethyl-, diethyl-, di-n-butyl-,
and n-butylbenzyl phthalate esters. In addition, environmental samples tend .
to have considerable amounts of dissolved metals (e.g. iron) and fats.
These form an insoluble floe and soapy emulsion when extracted using the
Method 625 base/neutral extraction scheme employing either manual or continuous
extraction. The acid/neutral scheme minimizes this problem. When the
sample pH is made first acidic (A/NI), emulsion formation is limited. When
the sample pH is re-adjusted and made caustic (base extract), all of the
target compounds of interest except benzidine and aniline have already
been extracted. Interestingly, these compounds have been dropped as target
compounds from the EPA Superfund Program (10). All of the current Superfund
target compounds are extracted with a single A/N extraction. The results of
this work suggest that much time, labor, and expense could be saved by the
A/N extraction scheme while not compromising the quality of the analytical
61
-------
results. The use of a neutral pH following the acid/neutral extraction
was found to recover the relatively basic target compounds aniline and
benzidine. However, the broad pH extraction range afforded by the
acid/neutral and base extraction procedure assures the recovery of more
basic organic compounds (non-target compounds) potentially present in
environmental samples.
The continuous extractor was found to effectively extract environmental
samples including: ground water, sewage influent, and estuarine and
industrial effluents. The levels of target and tentatively identified
compounds obtained when the CE was used equaled or exceeded those obtained
from manually extracted samples. The fact that the continuous extractor
resulted in excellent recoveries of complex priority pollutant mixtures
(48 compounds) and gave comparable results to manual extraction of
environmental samples indicated that the chemical reactions during the CE
process were not significant. These reactions were probably minimized by
the large volume (350 ml) of solvent employed in all extractor flasks and
changing of the solvent with each pH adjustment (24-hour period of exposure
to 40°C).
During these experiments, several difficulties were encountered with the
continuous extractors. The extractors require approximately twice the
volume of methylene chloride as used for manual separatory funnel extraction.
Our laboratory is investigating the possibility of re-distilling spent
solvent. The extractors require cooling water. The number of condensers
in series may be limited by this cooling capacity. A re-circulating chiller
was employed in this work. Condensation of room moisture on the cooling
62
-------
lines etc. may prove annoying in humid climates. Our laboratory has found
pipe insulation to be effective in controlling this problem. Finally, the
continuous extraction process does not lend itself to quick turnaround
time, in that, 48 hours is needed to complete the process. However, the
analyst is free to perform other tasks during this period.
The one piece all glass continuous extractor employed in this work was
found to have the following advantages:
0 The extractor was easy to clean and could be fired at 500°C.
0 The flat-bottom design allows the use of a magnetic stirrer.
This may be useful for samples containing settleable solids which
accumulate at the aqueous/solvent interface.
0 Because of the dimensions of the extractor, the solvent dropping
from the condenser strikes the aqueous surface and breaks into
many small droplets. This increased the surface area of the
extracting solvent and aided extraction, yet required no fragile
frit or elaborate stirring mechanism.
63
-------
Acknowledgement
The authors express their appreciation to Elaine Rossback and Ann Donaldson,
who typed this manuscript.
Registry No. N-Nitrosodimethylamine, 62-75-8; Phenol, 108-95-2; Aniline,
62-53-34; bis(2-Chloroethyl)ether, 111-44-4; 2-Chlorophenol, 95-57-8;
1,3-Dichlorobenzene, 541-73-1; 1,4-Dichlorobenzene, 106-46-7; Benzyl
Alcohol, 100-51-6; 1,2-Oichlorobenzene, 95-50-1; 2-Methylphenol,
95-48-7; bis(2-chloroisopropyl)ether, 39638-32-9; 4-Methylphenol,
106-44-5; N-Nitroso-di-n-propylamine, 621-64-7; Hexachloroethane,
67-72-1; Nitrobenzene, 98-95-3; Isophorone, 78-59-1; 2-Nitrophenol,
88-75-5; 2,4-Dimethylphenol, 105-67-9; Benzoic Acid, 65-85-0;
Bis(2-Chloroethoxy)methane, 111-91-1; 2,4-Dichlorophenol, 120-83-2;
1,2,4-Trichlorobenzene, 120-82-1; Naphthalene, 91-20-3; 3-Chloroani1ine,
106-47-8; Hexachlorobutadiene, 87-68-3; 4-Chloro-3-methylphenol, 59-50-7;
2-Methylnaphthalene, 91-57-6; Hexachlorocyclopentadiene, 77-47-4;
2,4,6-Trichlorophenol, 88-06-2; 2,4,5-Trichlorophenol, 95-95-4;
2-Chloronaphthalene, 91-58-7; 2-Nitroaniline, 88-74-4; Dimethylphthalate,
131-11-3; Acenaphthylene, 208-96-8; 3-Nitroaniline, 99-09-2; Acenaphthene,
83-32-9; 2,4-Oinitrophenol, 51-28-5; 4-Nitrophenol, 100-02-7; Dibenzofuran,
132-64-9; 2,4-Dinitrotoluene, 121-14-2; 2,6-Dinitrotoluene, 606-20-2;
Diethylphthalate, 84-66-2; 4-Chlorophenyl phenylether, 7005-72-3;
Fluorene, 86-73-7; 4-Nitroani1ine, 100-01-6; 4,6-Dinitro-2methylphenol,
543-52-1; 4-Bromophenyl phenylether, 101-55-3; Hexachlorobenzene,
118-74-1; Pentachlorophenol, 87-86-5; Phenanthrene, 85-01-8;
Anthracene, 120-12-7; Di-n-butylphthalate, 84-74-2; Fluoranthene,
206-44-0; Benzidine, 92-87-5; Pyrene, 129-00-0; Butylbenzylphthalate,
85-68-7; 3,3'-Dichlorobenzidine, 91-94-1; Benzo(a)anthracene, 56-55-3;
Bis(2-ethylhexy)phthalate, 117-81-7; Chrysene, 218-01-9; Oi-n-octyl-
phthalate, 117-84-0; Benzo(b)fluoranthene, 205-99-2; Benzofk)fluoranthene,
207-08-9; Benzo(a)pyrene, 50-32-8; Indeno(l,2,3-cd)pyrene, 193-39-5;
Dibenzo(a,h)anthracene, 53-70-3; Benzo(g,h,iJperylene, 191-24-2.
64
-------
References
1. "Guidelines Establishing Test Procedures For The Analysis of Pollutants
Under The Clean Water Act; Final Rule and Interim Final Rule and
Proposed Rule", 40 CFR Part 136, Federal Register, October 26, 1984,
Vol. 49, No. 209, Part VIII, 43234-4344?.
2. Shackelford, W. M. and McGuire, ,). M., Spectra, Vol. 10, No. 4, 1986,
pp. 17-21.
3. Eichelberger, J. W., Kerns, F.. H., and Rudde, W. L., Analytical
Chemistry, Vol. 55, No. 9, August 1983, pp. 1471-1479.
4. Kloepfer, R. n., Dias Jr., R., Fairless, B. J., "Chemistry in Water
Reuse", Cooper, W. T. editor, Ann Arbor Science, Ann Arbor,
MI, Vol. I, 1981, pp. 207-227.
5. Berg, E. W., "Physical and Chemical Methods of Separation", McGraw-Hill
Rook Co., Inc., N.Y. 1963, pp. 50-79.
6. Morrison, G. H., Freiser, H., "Solvent Extraction in Analytical
Chemistry", J. Wiley and Sons, N.Y., 1957, pp. 7-105.
7. Fisk, J. F., Haeberer,' A. H., and Kovell, S. P., Spectra. Vol. 10,
No. 4, 1986, pp. 22-39.
8. Callaham, M. A. and Slimak, M. W., "Water Related Environmental Fate
of 129 Priority Pollutants", Volume II, National Technical Information
Service,. U. S. Dept. of Commerce, Springfield, VA, pp. 94-6.-94-9.
9. "Handbook of Chemistry and Physics", Weast, R. C. editor, Chemical
Rubber Co., Cleveland, Ohio, 49th edition, p. D-87.
10. U. S. EPA Contract Laboratory Program, Statement of Work for Organics
Analysis, Multi-Media, Multi-Concentration, 7/85 revision.
65
------- |