Non-Purgeable Volatile Organic Compounds Rapidly Determined by Gas Chromatography/Mass Spectrometry Using Direct Aqueous Injection

EPA/600/A-95/056
NON-PURGEABLE VOLATILE ORGANIC COMPOUNDS RAPIDLY DETERMINED BY
GAS CHROMATOGRAPHY/MASS SPECTROMETRY USING DIRECT AQUEOUS
INJECTION
Steven M. Pyle and Alvin B. Marcus*, U.S. Environmental Protection Agency, EMSL-LV,
Las Vegas, NV 89193-3478; Linda S. Johnson, U.S. Environmental Protection Agency,
NEIC, Denver, CO 80225
ABSTRACT
A direct aqueous injection (DAI) method was developed for the determination of 18
non-purgeable volatile organic compounds of which 9 have no EPA-approved method. These
polar liquids were spiked into distilled water at 1- to 100-ppm levels and analyzed in triplicate
at 7 concentration levels using a fused-silica capillary column interfaced to an ion trap mass
spectrometer. Using internal standardization, the relative response factors and relative retention
times for the 18 compounds were determined. Duplicate data were collected using on-column
and splitless injectors. Accuracy and method detection limits (MDLs) were calculated from 10
replicate injections of 2-ppm standards. For splitless injection, the average relative standard
deviation for the compounds was 19% and the average MDL was 800 ppb; for on-column
injection, the respective values were 13% and 800 ppb. Agreement with EPA-established
criteria for 4-bromofluorobenzene will also be shown. Data from the EMSL-LV Analytical
Sciences Division will be presented to show conditions and limitations involving method
parameters, such as column type, injection volume, and spectral quality. Attempts to optimize
method precision and peak shape will also be discussed.
INTRODUCTION
The ion trap mass spectrometer, a recent commercial innovation, has made possible the
detection of organic compounds at the picogram level in the full-scan mode. Using fiL sample
injection volumes, this translates into potential parts-per-billion sensitivity for the direct
injection and analysis of aqueous environmental samples. Direct aqueous injection (DAI) is
rapid, simple, and sensitive. It also eliminates the need for waste-solvent disposal and is
compatible with EPA pollution prevention policy. Compared with solvent extraction and
purge-and-trap preparatory methods, DAI is particularly suited to analyzing aqueous samples
for non-purgeable, poorly purgeable, or non-extractable, volatile organic pollutants.
~Senior Environmental Employee Program Enrollee hosted by the National Association for
Hispanic Elderly

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EXPERIMENTAL
Standard Solutions
Stock solutions were prepared by using a 10-^L syringe to add the neat liquid to
distilled water in a 100-mL volumetric flask. The density (Table 1) and volume added were
used to calculate the concentration in parts-per-million (ppm). Serial dilutions were prepared
in 10-mL volumetric flasks. Triplicate injections at 7 concentrations over a 2-decade range
were used to calculate the relative response factors (RRF). MDLs1 were determined at the 2-
ppm level and 10 replicate injections.
Conditions
After some initial experimentation, the following conditions were used to collect the
data for method development. Two different gas chromatographic columns were used.
GC Conditions
initial temperature	35 *C
initial time	5 min
temperature rate	10 *C/min
final temperature	165 *C
final hold time	2 min
total run time	20 min
transfer line	200 *C
On-column Injection
initial temperature	100 "C
initial time	0.1 min
temperature rate	200 "C/min
final temperature	260 *C
final hold time	1 min
total run time	1.9 min
Splitless Injection
temperature	200 °C
splitless time	30 sec
split ratio	20:1
Mass Spectrometer
scan range
scan time
mass defect
acquire time
29	to 180 amu
0.6 sec/scan
30	mmu/100 amu
17 min
Column #1
dimensions
liquid phase
head pressure
linear velocity
30 m x 0.53 mm id x 1.5 fim film
5% diphenyl-95 % dimethyl polysiloxane
12 psig
37.5 cm/sec of helium carrier gas

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EPA/6QQ/A-95/056
NON-PURGEABLE VOLATILE ORGANIC COMPOUNDS RAPIDLY DETERMINED BY
GAS CHROMATOGRAPHY/MASS SPECTROMETRY USING DIRECT AQUEOUS
INJECTION
Steven M. Pyle and Alvin B. Marcus*, U.S. Environmental Protection Agency, EMSL-LV,
Las Vegas, NV 89193-3478; Linda S. Johnson, U.S. Environmental Protection Agency,
NEIC, Denver, CO 80225
ABSTRACT
A direct aqueous injection (DAI) method was developed for the determination of 18
non-purgeable volatile organic compounds of which 9 have no EPA-approved method. These
polar liquids were spiked into distilled water at 1- to 100-ppm levels and analyzed in triplicate
at 7 concentration levels using a fused-silica capillary column interfaced to an ion trap mass
spectrometer. Using internal standardization, the relative response factors and relative retention
times for the 18 compounds were determined. Duplicate data were collected using on-column
and splitless injectors. Accuracy and method detection limits (MDLs) were calculated from 10
replicate injections of 2-ppm standards. For splitless injection, the average relative standard
deviation for the compounds was 19% and the average MDL was 800 ppb; for on-column
injection, the respective values were 13% and 800 ppb. Agreement with EPA-established
criteria for 4-bromofluorobenzene will also be shown. Data from the EMSL-LV Analytical
Sciences Division will be presented to show conditions and limitations involving method
parameters, such as column type, injection volume, and spectral quality. Attempts to optimize
method precision and peak shape will also be discussed.
INTRODUCTION
The ion trap mass spectrometer, a recent commercial innovation, has made possible the
detection of organic compounds at the picogram level in the fall-scan mode. Using fiL sample
injection volumes, this translates into potential parts-per-billion sensitivity for the direct
injection and analysis of aqueous environmental samples. Direct aqueous injection (DAI) is
rapid, simple, and sensitive. It also eliminates the need for waste-solvent disposal and is
compatible with EPA pollution prevention policy. Compared with solvent extraction and
purge-and-trap preparatory methods, DAI is particularly suited to analyzing aqueous samples
for non-purgeable, poorly purgeable, or non-extractable, volatile organic pollutants.
~Senior Environmental Employee Program Enrollee hosted by the National Association for
Hispanic Elderly

-------
EXPERIMENTAL
Standard Solutions
Stock solutions were prepared by using a 10-/*L syringe to add the neat liquid to
distilled water in a 100-mL volumetric flask. The density (Table 1) and volume added were
used to calculate the concentration in parts-per-million (ppm). Serial dilutions were prepared
in 10-mL volumetric flasks. Triplicate injections at 7 concentrations over a 2-decade range
were used to calculate the relative response factors (RRF). MDLs1 were determined at the 2-
ppm level and 10 replicate injections.
Conditions
After some initial experimentation, the following conditions were used to collect the
data for method development. Two different gas chromatographic columns were used.
GC Conditions
initial temperature 35 °C
initial time	5 min
temperature rate	10 "C/min
final temperature	165 *C
final hold time	2 min
total run time	20 min
transfer line	200 *C
On-column Injection
initial temperature	100 °C
initial time	0.1 min
temperature rate	200 * C/min
final temperature	260 *C
final hold time	1 min
total run time	1.9 min
Splitless Injection
temperature	200 *C
splitless time	30 sec
split ratio	20:1
Mass Spectrometer
scan range
scan time
mass defect
acquire time
29	to 180 amu
0.6 sec/scan
30	mmu/100 amu
17 min
Column 01
dimensions
liquid phase
head pressure
linear velocity
30 m x 0.53 mm id x 1.5 /xm film
5% diphenyl-95 % dimethyl polysiloxane
12 psig
37.5 cm/sec of helium carrier gas

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Column #2
dimensions	30 m X 0.32 mm id x 0.25 /xm film
liquid phase	Carbowax PEG
head pressure	20 psig
linear velocity	50 cm/sec of helium carrier gas
In order to match the flow from a wide-bore column to the ion trap vacuum manifold
and to facilitate changing columns, a post-column splitter was used (Fig. 1). This
configuration resulted in 35% of the 0.53 mm id column effluent (50 % of the 0.32 mm id
column effluent) going into the mass spectrometer manifold.
On-column Injector
Table 1 shows the compound number, quantitation ion, density, retention times,
relative response factor, and MDL for each of the 18 analytes and internal standard. Figure 2
shows the column #1 chromatogram of the separation of the 18 analytes and internal
standard.
The method showed adequate MDLs and good separation on both columns. However,
the mass spectra generated on the ion trap were somewhat different from the NIST library
spectra. This is due to the low-molecular-weight nature of these compounds. The oxygen and
nitrogen background interfered with ions in the 28 to 33 amu range. Also there were inherent
differences in ion trap spectra compared to conventional quadrupole mass spectrometers.
"Y" Connector
Capillary Column
Transfer Line ^
to charcoal trap
Sy//y y/////////////////
Gas Chromatograph
Mass Spectrometer
Vacuum Manifold
! Igure 1. Post-column split diagram.
RESULTS AND DISCUSSION

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purgeable volatiles2, these problems were not encountered because of the higher molecular
weights of these halogenated compounds.
CONCLUSIONS
1)	DAI method showed good chromatographic separation on two columns of different
dimensions and liquid phases.
2)	Adequate sensitivity was obtained for non-purgeable volatiles.
3)	DAI is rapid, easily applied, and generates no waste solvent.
4)	This research and previous work3 show that direct aqueous injection is feasible for these
compounds with a variety of columns, injectors, injection volumes, and instruments.
Table 1. Compound versus quantitation ion, density, retention time, relative response factor,
and method detection limit.
no.
compound
ion
density
RT1a
RT2b
RRF°
MDL


m/z
g/mL
min.
mln.

ppm
ISd
d5-Nitrobenzene
82
1.253
15:45
16:13
1.000
—
1
Ethanol
45
0.785
1:45
2:16
0.106
0.88
2
Acetonitrile
41
0.786
1:55
3:15
0.090
0.66
3
2-Propanone
43
0.791
1:56
1:26
0.425
0.67
4
Diethyl ether
59
0.714
2:03
1:02
0.031
1.16
5
Acryionitrile
53
0.806
2:12
3:03
0.084
0.59
6
1-Propanol
59
0.804
2:38
4:02
0.062
1.36
7
Propionitrile
54
0.772
2:53
3:41
0.159
1.36
8
2-Butanone
43
0.805
3:13
1:55
0.540
0.58
9
Ethyl acetate
43
0.902
3:38
1:50
0.764
0.58
10
1-Butano!
56
0.805
5:07
7:37
0.201
0.89
11
3-Pentanone
56
0.814
6:13
2:46
0.488
0.65
12
p-Dioxane
88
1.034
6:35
4:27
0.189
0.54
13
Methyl methacrylate
69
0.936
6:46
3:15
0.297
0.55
14
4-Methyl-2-pentanone
43
0.800
7:40
3:15
' 0.874
0.68
15
Ethyl methacrylate
69
1.100
9:03
4:13
0.554
0.39
16
2-Hexanone
43
0.812
9:07
5:06
1.052
0.76
17
3-Picoline
93
0.957
11:01
10:02
0.745
1.04
18
1,3-Dichloro-2-propanol
79
1.351
11:47
16:26
0.351
1.18
a retention time on Column #1
b retention time on Column #2
c relative response factor
d internal standard

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Ou-owatoB**®" Plot	File: C:\PIAGMtif\DB-S3 Data! Jan-18-1995 14:25
Coiment: N0M-PUR6EABLI UOLAIILES SB PPHJ W HEOH AND INT SID; HT=190
Scan No! 122	Retention Tina: 1:13 HIC: 21950 Naas Range; 29 - 115
Plott#*: 1 to 1699	Raitg«: 1 to 1699 100* = 6280B8
1 my.	17
101-
15
OB-5 column
0.5 uL aqueous injection
B:fH
16
18
400
4:m
1280
12:00
1600
16:08
Figure 2. DB-5 chromatogram of 18 compounds and IS. See Table 1 for peak IDs.
Table 2. 4-Bromofluorobenzene tune criteria.
4-1FB mass
Method 524
Method 8240b
DAI average
%rsd*
50
8 to 40% of mass 95
15 to 40% of mass 95
22
4
75
30 to 66% of mass 95
30 to 65% of mass 95
56
2
95
base peak, 100%
base peak, 100%
100
30
96
5 to 9% of mass 95
5 to 9% of mass 95
6
2
173
< 2% of mass 174
< 2% of mass 174
0
-
174
50 to 120% of mass 95
> 50% of mass 95
70
3
175
4 to 99K of mass 174
5 to 9% of mass 174
8
1
176
93 to 101% of mass 174
95 to < 101% of mass 174
101
1
177
5 to 9% of mass 176
5 to 9% of mass 176
6
3
*n=5
1.	Glaser, J. A.; Forest, D. L.; McKee, G. D.; Quave, S. A.; Budde, W. L., Envir. Sci. and Tech..
1981,16, 1426.
2.	Pyle, S. M.; Guika, D .F., Talanta. 1994, 41, 1845-1852.
3.	Gurka, D. F.; Pyle, S. M.; Titus, R., Anal. Chem.. 1992, 64, 1749-1754.
A
/

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tM5,i.-Lv w-u/4 TECHNICAL REPORT DATA Marcn 13, iyso
(Please read Instructions on the reverse before compter
1. REPORT NO.
EPA 600/A-95/Q5g
2.
3.
4. TITLE AND SUBTITLE
Non-Pugeable Volatile Organic Compounds Rapidly Determined
by Gas Chromatography/Mass Spectrometry Using Direct Aqueous Injection
5. REPORT DATE
6. PERFORMING ORGANIZATION CODE
7. AUTHORIS)
Pyle, S.M., Marcus, A.B.; (EMSL-LV)
Johnson, L.S. (NEIC)
8. PERFORMING ORGANIZATION REPORT NO,
9. PERFORMING ORGANIZATION NAME ANO ADDRESS
U.S. Environmental Protection Agency
EMSL-Las Vegas & NEIC-Denver
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
! 12, SPONSORING AGENCY NAME AND ADDRESS
U.S Environmental Protection Agency
Environmental Monitoring Systems Laboratory
Las Vegas, Nevada 89193
13. TYPE OF REPORT AND PERIOD COVERED
symposium Paper
14. SPONSORING AGENCY CODE
EPA 600/07
15. SUPPLEMENTARY NOTES
Pyle, S.M.; Marcus, A.B; Johnson, L.S. "Non-Purgeable Volatile Organic Compounds Rapidly
Determined by Gas Chromatography/Mass Spectrometry Using Direct Aqueous Injection" Presented at the 4th International Field Screening For
Hazardous Wastes and Toxic Chemicals, Las Vegas, NV 02/22-25/95
16. ABSTRACT
A direct aqueous injection (DAI) method was developed for the determination of 18 non-purgeable volatile organic
compounds of which nine have no EPA-approved method. These polar liquids were spiked into distilled water at 1- to
100-ppm levels and analyzed in triplicate at seven concentration levels using a fused-silica capillary column interfaced to
an ion trap MS. Using internal standardization, the relative response factors ad relative retention times for the 18
compounds were determined. Duplicate data were collected using on-column and splitless injectors. Accuracy an method
detection limits (MDLs) were calculated from 10 replicate injections of 2-ppm standards. For splitless injection, the
average relative standard deviation for the compounds was 19% and the average MDL was 88 ppb; for on-column
injection, the relative values were 13% and 800 ppb. Agreement with EPA-established criteria for 4-bromofluorobenzene
will also be shown. Data from the EMSL-LV Analytical Sciences Division will be presented to show conditions and
limitations involving method parameters, such as column type, injection volume, and spectral quality. Attempts to
optimize method precision and peak shape will also be discussed.
17. KEY WOROS ANO OOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Direct Aqueous Injection, Analytical Methods,
Volatile Organic Compounds, VOCs, Ion Trap MS,
4-bromofluorobenzene, Fused-silica Capillary Column

18. DISTRIBUTION STATEMENT
Release to the Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
6 pages
20. SECURITY CLASS (This page/ |22, PRICE
Unclassified |
EPA Form 2220-1 (H«». 4-77) previous edition is obsolete

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