USEPA Methods 8270 and 8260 on a Single GCMS Without...

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)

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Instrument Configuration

GCMS-QP2010 SE

Production Workhorse 6

Instrument Configuration

GCMS-QP2010 SE

Production Workhorse 7

Instrument Configuration (cont.)

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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)

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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

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Instrument Configuration (cont.)

Born in Kyoto

Made in the USA

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• 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

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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

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Why Constant Linear Velocity? (cont.)

Linear Velocity

Linear Velocity

Oven Temp

Head Pressure

Flow

Linear Velocity

Constant

Pressure

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Why Constant Linear Velocity? (cont.)

Linear

Velocity

Linear

Velocity

Head Pressure

Flow

Linear Velocity

Oven Temp

Constant

Flow

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Why Constant Linear Velocity? (cont.)

Constant

Linear Velocity

Head Pressure

Linear Velocity

Flow

Oven Temp

Linear Velocity

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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

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Analytical Results (cont.)

DDT Breakdown

DDT (expanded)

DDE DDD

Benzidine and Pentachlorophenol Tailing

Benzidine

Pentachlorophenol

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Analytical Results (cont.)

EPA Method 8270

50 µg/mL calibration standard

TIC – 66 compounds resolved

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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

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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%

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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%

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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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