Transcript TO-15 or not TO-15? - H&P Mobile GeoChemistry, Inc.

TO-15 or not TO-15?
That is the question.
James Picker, Ph.D.
H&P Mobile GeoChemistry
Escondido, CA
Objective
Compare/Contrast
EPA Method 8260B vs. EPA Method TO-15/TO-14A
Used for the analysis of VOCs in soil vapor (gas) to
measure health risk
H&P Mobile GeoChemistry
Escondido, CA
Perceived (advertised?) Difference
OR
H&P Mobile GeoChemistry
Escondido, CA
Actual difference
OR
H&P Mobile GeoChemistry
Escondido, CA
Summary EPA 8260 vs. TO-15/14A
Data Reduction
SAME
GC/MS System
Sample Preparation
IDENTICAL
SLIGHTLY DIFFERENT
H&P Mobile GeoChemistry
Escondido, CA
Similarities
GC/MS Method (SCAN or SIM)

GC with FSCC (20-60m X 0.18-0.32mm id)

LRMS (quadrupole, ion trap, TOF)

*Concentration of compounds on multiadsorbent trap*

Uses Internal Standards/Surrogate(s) for accuracy/QC

Multipoint Calibration ICAL, linearity checks, Daily CCV

Varying sample size permitted

Quant by RFs
H&P Mobile GeoChemistry
Escondido, CA
Differences
Standards and Sample Preparation
EPA 8260B (modified)
EPA TO-15/14A
*Standards in liquid (MeOH)*
*Standards in Air (N2)*
Purge and trap
Purged from headspace and H2O
using He or dry purging
Water management
Desorption direct to GC/MS
Vacuum (or Pressure) flow and Trap
pulled from cylinder, using pump or
pressure
Desorption to cryofocus or directly to
GC/MS.
H&P Mobile GeoChemistry
Escondido, CA
Standards in Water or Air
-
H&P Mobile GeoChemistry
Escondido, CA
Compounds Analyzed equally well by
EPA 8260 or TO-15
• BTEX, Trimethylbenzenes, Freons
• PCE, TCE, vinyl chloride, DCEs, 1,2DCPE, 1,1,1,2- TCA
• 1,1,1-TCA,
H&P Mobile GeoChemistry
Escondido, CA
Compounds Analyzed with a slight high
bias by EPA 8260 versus TO-15
• MTBE, other oxygenates
• 1,1,2,2-TCA, 1,2- DCA, 1,1,2-TCA
• Naphthalene
• rest of common 8260 list
H&P Mobile GeoChemistry
Escondido, CA
Compounds Analyzed with a high
bias by EPA 8260 versus TO-15
Ethanol, TBA
1,4 Dioxane
Acetone & other ketones
Any water soluble low
volatility compound
H&P Mobile GeoChemistry
Escondido, CA
Differences II
Calibration and Range
EPA 8260B (modified)
EPA TO-15/14A
“Typical” Calibration 500 – 50000
ug/m3 (160-16000 ppbv for benzene)
“Typical” Calibration 3-120 ug/m3
benzene (1-40 ppbv)
MDLs 100 ug/m3 (31 ppbv benzene)
MDLs 0.3 ug/m3 benzene( 0.1ppbv)
For 8260 SIM 10 ug/m3 (3 ppbv
benzene
For TO-15 SIM 0.03 ug/m3 benzene
(0.01ppbv)
H&P Mobile GeoChemistry
Escondido, CA
Calibration Range
MDL to highest standard
assumes 20 cc sample
Normal Range
8260 SCAN
Extended by dilution
8260 SIM
TO-15/14A SCAN
TO-15/14A SIM
10-2
10-1
1
10
102
ug/m3
H&P Mobile GeoChemistry
Escondido, CA
103
104
105
Fail Levels
TCE @ subslab
TCE @ 5’bgs
CA-EPA
EPA R9
8260 SCAN
8260 SIM
TO-15/14A SCAN
TO-15/14A SIM
10-2
10-1
1
10
102
ug/m3
H&P Mobile GeoChemistry
Escondido, CA
103
104
105
Fail Levels
Benzene @ subslab
Benzene @ 5’bgs
CA EPA
EPA R9
8260 SCAN
8260 SIM
TO-15/14A SCAN
TO-15/14A SIM
10-2
10-1
1
10
102
ug/m3
H&P Mobile GeoChemistry
Escondido, CA
103
104
105
Project BL 4FEB05
results in ug/L
Sample
TO-15
PCE
8260
PCE
TO-15
TCE
8260
TCE
TO-15
c12DCE
8260
c12DCE
TO-15
t12DCE
8260
t12DCE
TO-15
F-113
8260
F-113
SV1
128
88
42
31
<1
<1
<1
<1
1.6
1.1
SV2
399
280
134
100
4.4
3.7
1.7
1.4
3.4
2.7
SV3
95
46
40
31
<1
<1
<1
<1
1.7
1.6
SV4
541
330
75
60
<1
<1
<1
<1
<1
<1
SV5
169
110
70
65
1.5
1.7
<1
<1
3.4
3.1
SV6
234
150
138
110
3.6
3.2
<1
<1
4.8
4.1
SV7
108
54
25
17
<1
<1
<1
<1
3.1
2.1
SV8
250
120
120
74
4.7
3.5
<1
<1
9.9
4.8
AVG
%Diff.
52
28
13
19
Average % Diff across all compounds = 38%
H&P Mobile GeoChemistry
Escondido, CA
28
Project MC 1FEB05
results in ppbv
Sample
TO-15
PCE
8260
PCE
TO-15
TCE
8260
TCE
TO-15
c12DCE
8260
c12DCE
TO-15
111TCA
8260
111TCA
TO-15
F-113
8260
F-113
SG1
190
250
<16
<25
32
<25
<16
<25
NA
NA
SG3
59
83
110
93
<16
<25
40
36
NA
NA
SG8
<16
<14
<16
64
<16
<25
540
370
NA
NA
SG12
<16
<14
1300
910
91
65
360
261
NA
NA
SG13
29
<14
98
81
<16
<25
28
<20
NA
NA
H&P Mobile GeoChemistry
Escondido, CA
Conclusions
1. For most vapor intrusion compounds of interest,
methods yield identical results
2. For more water soluble compounds 8260 is
within factor of 2. Fine for VI calculations
3. A few compounds may require TO method.
Some compounds may require 8260 method
4. On-site analysis assists in decision making,
regulatory QA requirements and assurance of
tracer compound integrity
H&P Mobile GeoChemistry
Escondido, CA
Recommendations
 Choose either or a combination of methods,
depending on compounds and DLs required
 Select on-site analysis for decision making,
regulatory QA requirements (assurance of tracer
compound integrity, purge volume testing, etc.)
 Do onsite TO-15 where levels are low
 Do onsite 8260 where levels are moderate to high
 Follow with offsite TO-15 for Quality Assurance
H&P Mobile GeoChemistry
Escondido, CA
H&P Mobile GeoChemistry
Escondido, CA
H&P Mobile GeoChemistry
Escondido, CA
H&P’s Solutions
Option 1 – Where 8260B Meets Project DQOs:
On-site, full QC 8260B fulfilling DTSC/LA-RWQCB requirements with off-site TO15 confirmation on a sub-set of samples.
Option 2 – Where TO-14/15 is required to meet Project DQOs:
On-site screening-level 8260B of all samples with of-site analysis of ALL samples
by TO-15.
Option 3 – For larger projects with lower DLs:
On site TO-15
All Options:
Fulfill all DTSC soil gas advisory requirements
Allow on-site analysis for leak/tracer compound test
Guarantee sample integrity
Provide real-time data for real-time decisions
James Picker, Ph.D.
148 Vinewood Street
Escondido, CA 92029
(800) 834-9888
www.HandPmg.com