USEPA Methods 8270 and 8260 on a Single
GCMS Without Changing Columns
Richard Whitney, Laura Chambers, Clifford Taylor
Shimadzu Scientific Instruments, Inc.
Columbia, MD
Spotlight on Method
8270 Instrumentation
USEPA Methods 8270 and 8260 on a Single
GCMS Without Change Columns
Richard Whitney, Laura Chambers, Clifford Taylor
Shimadzu Scientific Instruments, Inc.
Columbia, MD
Spotlight on Method
8270 Instrumentation
Venting the MS to . . .
• Small laboratory
• Limited budget
• Multiple applications
• No time
Problem
3
The Big Bang Theory – CBS.com
• 8260 and 8270
• Single GCMS
• Two inlets, two columns
• No venting
Solution
4
The Big Bang Theory – CBS.com
What We Did
Instrument configuration
Optimize method parameters
Analytical results (aka data)
5
Instrument Configuration
GCMS-QP2010 SE
Production Workhorse 6
Instrument Configuration
GCMS-QP2010 SE
Production Workhorse 7
Instrument Configuration (cont.)
8
GCMS Twin Line Kit
Instrument Configuration (cont.)
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Instrument Configuration (cont.)
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Instrument Configuration (cont.)
58 L/sec (He)
Pfeiffer TMP (Rotary pump 30 L/min)
11
Instrument Configuration (cont.)
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Instrument Configuration (cont.)
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Ecology Mode saves ~26%
Instrument Configuration (cont.)
Parameter EPA Method 8260 EPA Method 8270
Sample introduction Purge-and-trap Liquid syringe
Liner Shimadzu multi-purpose
split liner, no glass wool
Shimadzu multi-purpose
split liner, no glass wool
Injection conditions Split 75:1 Split 10:1
Column Rxi-624Sil MS
20 m x 0.18 mm x 1.4 µm
Rxi-5Sil MS
20 m x 0.18 mm x 0.18 µm
Maximum column
temperature Program = 320 °C Program = 350 °C
Carrier gas Helium, constant linear velocity mode
MS pump Single stage TMP, max flow 4 mL/min (He)
MS interface 225 °C
Ion source EI, 200 °C
14
Instrument Configuration (cont.)
Born in Kyoto
Made in the USA
15
• Primary objectives
1. Keep total column flow rate
below 4 mL/minute
2. Keep maximum oven
temperature below 320 °C
3. Keep GC run time as short
as practical
Method Optimization
16
The Big Bang Theory – CBS.com
Method Optimization (cont.)
Parameter Method 8260
Primary
Method 8270
Inactive
Column constant
linear velocity
45 cm/second
~0.8 mL/min
30 cm/second
~0.5 mL/min
Maximum total
column flow ~1.3 mL/minute
Oven program
35 °C (5 min)
20 °C/min to 220 °C
(hold 2.5 min)
NA
GC run time 12.5 minutes NA
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Method Optimization (cont.)
Parameter Method 8260
Inactive
Method 8270
Primary
Column constant
linear velocity
30 cm/second
~0.5 mL/min
40 cm/second
~0.7 mL/min
Maximum total
column flow ~1.2 mL/minute
Oven program NA
45 °C (0.5 min)
25 °C/min to 315 °C
(hold 4.2 min)
GC run time NA 16 minutes
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Why Constant Linear Velocity?
Van Deemter Plot
Linear Velocity – Isothermal Oven
Optimal LV for
each carrier
Gas
19
Why Constant Linear Velocity? (cont.)
Head Pressure (kPa)
Flow (ml/min)
Linear Velocity (cm/sec)
Oven Temp
With temperature programming:
1. Viscosity of gas increases
2. Gas expands
3. Flow rate and LV drop
20
Why Constant Linear Velocity? (cont.)
Linear Velocity
Linear Velocity
Oven Temp
Head Pressure
Flow
Linear Velocity
Constant
Pressure
21
Why Constant Linear Velocity? (cont.)
Linear
Velocity
Linear
Velocity
Head Pressure
Flow
Linear Velocity
Oven Temp
Constant
Flow
22
Why Constant Linear Velocity? (cont.)
Constant
Linear Velocity
Head Pressure
Linear Velocity
Flow
Oven Temp
Linear Velocity
23
Why Constant Linear Velocity? (cont.)
Constant Flow
Linear velocity = 20 cm/sec
Constant Pressure
Linear velocity = 15 cm/sec
Constant Linear Velocity
Linear velocity = 30 cm/sec
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Analytical Results
BFB Spectrum
EPA Method 8260
BFB Tune Criteria
Passed
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Analytical Results (cont.)
EPA Method 8260
10 µg/L calibration standard
TIC – 66 compounds resolved
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Analytical Results (cont.)
DFTPP Spectrum
EPA Method 8270
DFTPP Tune Criteria
Passed
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Analytical Results (cont.)
DDT Breakdown
DDT (expanded)
DDE DDD
Benzidine and Pentachlorophenol Tailing
Benzidine
Pentachlorophenol
28
Analytical Results (cont.)
DDT Breakdown
DDT (expanded)
DDE DDD
Benzidine and Pentachlorophenol Tailing
Benzidine
Pentachlorophenol
29
Analytical Results (cont.)
EPA Method 8270
50 µg/mL calibration standard
TIC – 66 compounds resolved
30
Analytical Results (cont.)
EPA Method 8270 Calibration
Range 8 points, 0.4 – 160 µg/mL
6 Internal Standards Acenaphthene-d10, Cyrysene-d12, 1,4-Dichlorobenzene-d4,
Naphthalene-d8, Perylene-d12, Phenanthrene-d10
40 µg/mL each
Response Factor 54 compounds < 15% RSD
Min. RF = 0.132, Pentachlorophenol
Max. RF = 3.966, bis(2-chloroisopropyl)ether
Linear Curve 12 compounds > 15% RSD
Min r = 0.997, 2,4-dinitrophenol
Max r = 0.999, 8 compounds
31
Analytical Results (cont.)
2-Nitrophenol (2 µg/mL)
r = 0.999
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Benzo(b&k)fluoranthenes (1 µg/mL)
Analytical Results (cont.)
RSDb = 6.1%
RSDk = 12.0%
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Analytical Results (cont.)
0.0
2.0
4.0
6.0
8.0
10.0
12.0
%R
SD
% Relative Standard Deviation (0.4 µg/mL*, n = 8)
62/66 RSD < 8%
39/66 RSD < 4%
34
Analytical Results (cont.)
0.0
20.0
40.0
60.0
80.0
100.0
120.0
Ave
rag
e %
Re
co
ve
ry
Average % Recovery (0.4 µg/mL*, n = 8)
57/66 Recovery 80 – 120%
35
Analytical Results (cont.)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
IDL (
µg
/mL
)
Statistical Instrument Detection Limit (0.4 µg/mL, n = 8)
60/66 IDL < 0.2 µg/mL
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Analytical Results (cont.)
DCM carryover < 1.0 ppb
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Analytical Results (cont.)
Acetone carryover ~ 1.0 ppb
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• Two methods
• Two intro techniques
• Two injection ports
• Two columns
• One MS
• All method criteria passed
• One happy customer
• Shimadzu application
note GCMS-1302
Summary
39
The Big Bang Theory – CBS.com
Acknowledgements
Richard R. Whitney, Ph.D.
Configuration insight and
all the hard work!
Julie Kowalski
Advice re column and conditions
Columns and standards
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Shimadzu Scientific Instruments
Products – People - Passion
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