The world leader in serving science

Ultra Fast GC Determination of Total Hydrocarbons (C7-C40) and BTEX in Water and Soils through Direct Resistively Heated capillary columns and Robotic Autosampler.

Fausto Munari e Andrea Cadoppi

ThermoFisher - Italy

2

Summary

Official regulations for Total Hydrocarbons: GC as replacement of IR

Ultra Fast GC and Triplus Autosampler

ISO 9377-2 with Ultra Fast GC

ISO 9377-2 (Mod.) with Ultra Fast GC

3

IR and GC methods

Method: EPA 418.1 ISO 9377-2TNRCC 1005 EPA 8015

Analysis Time: around 2 min 20 min

Infra Red GC

Extraction Solvent: CCl4, Freon n-pentane,(banned) n-hexane

TTCE

ISO/TR 11046 ISO/TR 11046(for Oil in soil and sediments)

2 minby Ultra Fast GC

4

How fast is UFGC?

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

50 100 150 200 250 300 350

Final oven temperature (°C)

Rat

e (°

C/m

in)

0

2

4

6

8

10

12

14

16

18

20

22

24

Rat

e (°

C/s

)

UFGC (direct resistive heating)

Conventional “fast” oven

5

Ultra Fast GC: Requirements

• Ultra Fast heating capability (100-1200 °C/min)

• Short capillary columns (typically 2-5m narrow-bore; or 0.32mm i.d. when separation power is not an issue)

• High pressure pneumatic control capability

• Fast Detector (High Frequency Response)

6

Direct column heating technology

The heating element and the T sensorare wrapped around the columnThe column is mounted in a “cage”ULTRA FAST Column Module

Dedicated heated interfaces forinjector and detector NO oven heating is required

The column module includes bothheating and temperature sensingelements

Capillary column

Heater

Temperature sensor Ceramic fiber

Column assembly

7

The column module in the oven

Column modules are housed in the GC oven and connected to inlet (SSL or PTV) and detector as a conventional capillary column

Configurations used for TPH analysis:

• SSL / FID• PTV / FID

FID Injector

Additional heated block

Trace GC Ultra oven

8

Trace GC Ultra Column Module

Assemblies of 2, 5, 10 m (0.1-0.32 mm i.d.)

Up to 20°C/s (1200 °C/min) temperature programming rates

Broad temperature range (from 35 to 370°C)

Cooling from 350°C to 50°C in about 1 min

If needed, also cryo cooling is available (0°C minimum temp)

FEATURES

Significant implications over conventional GC

• Faster analysis times• Higher column lifetime• Higher sensitivity: capability to handle trace analysis

9

0.0E+00

2.0E+04

4.0E+04

6.0E+04

8.0E+04

1.0E+05

1.2E+05

1.4E+05

1.6E+05

0 1 2 3 4 5 6 7 8 9 10

time (s)

FID

sig

nal (

uV)

300 °C/min 0.1 mm id column

PW1/2 = 0.10 s

20 °C/min 0.32 mm id column

PW1/2 = 1.6 s

nC20 (about 1ng) area 15000 (uV.s)

Increased sensitivity - Peak compression effect

Narrower peaks result in better signal to noise ratio

10

Ultra Fast Analysis of FAME

∼ 20 min

∼ 1 min

Classical Analysis30 m, 0.32 mm id, 0.25 um Column TR-510 °C/min

Ultra Fast GC Analysis5m, 0.10 mm id, 0.10 um Column TR-5300 °C/min

E7

E9

E10

E11 E

12

E13

E14

E15

E16

E17

E18

E19

E20E

8

E12 E13

E7

E9

E10

E11 E14

E15

E16

E17

E18

E19

E20E8

1 min

11

Retention Time repeatability study

nC25

nC23

nC22

nC20

9

8

7

6

nC185

nC164

nC143

nC122

nC101

Components

0 2 0 4 0 6 0 8 0 1 0 0 1 2 0

2 °C /s

1 0 °C /s

5 °C /s

35 s

60 s

110

s

Time (s)

1 2 3 46

5

7 8 9

10 °C/s

5 °C/s

2 °C/s

Carrier gas mode: constant flow(1 ml/min H2)Column 5m x 0.1 mm id, 0.1 um TR-570 to 330 °CSplit 1:200

12

Retention Time repeatability

• Clear Identification: SD << peak width

at ½ h at 5% h6×SD

window*Peak widthsRetention times

ComponentRate (°C/s)

0.1080.1700.0850.01829.95C25

0.0960.1450.0700.01625.54C20

0.054

0.096

0.084

0.084

0.090

0.090

0.090

0.090

0.096

0.168

0.120

0.135

0.230

0.199

0.180

0.180

0.470

0.420

0.360

0.400

0.0550.00915.98C12

0.0600.01612.68C10

10

0.1100.01450.56C25

0.0900.01441.99C20

0.0800.01523.26C12

0.0900.01516.56C10

5

0.2200.015106.69C25

0.2000.01585.26C20

0.1800.01639.01C12

0.1800.02823.35C10

2

SD (s)Mean (s)

* In a ± 3 SD span there is a probability of 99.7 % for a measure to fall in

13

ISO 9377-2

ISO Norm 9377-21. Extraction of 900ml of water with 50 ml of n-hexane

2. Purification of the extract through Florisil, to removeinterferences

3. Concentration of the extract from 50 to 1ml4. GC analysis (FID detector)

Solvent: n-hexane

Range of hydrocarbons: C10-C40

14

Hydrocarbon analysis in water and soils

Column :TR- 5m, 0.32 mm id, 0.25 um FT, T prog.: 40 (20s), 3.3 °C/s, 350 (30s), Sample: Soil extract (50 ng/ul tot hyd.), Injection: 1 ul SPLITLESS, Splitless time: 20 s, Carrier: He at 5 ml/min CF

Splitless injection

Soil extract (50 mg/l tot. hydroc.)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

time (min)

C40C10

2 minTotal hydrocarbons

15

Calibration curve 5-500 mg/lR2 0.9999

0

200

400

600

800

0 100 200 300 400 500 600Concentration (mg/l)

Are

a co

unts

(*10

^6)

Hydrocarbon analysis in water and soils

High linearity from 5 to 500 mg/lC40/C20 area ratio > 0.9 (required 0.8)RSD% on group peak absolute area 0.8%

16

Trace GC Ultra

SSL - UFM - Fast FID

Compliance with the requirements of the official methods

High sample/day throughput!

100 samples in about 8h (a work-day)!

SamplingRun Time 5 minCooling Time

ISO 9377-2

17

ISO 9377-2

Gain in speed• Faster run• Faster cooling

Gain in sensitivity• Peaks compression:

peaks are narrower and consequently higher

0

2 5 0

5 0 0

7 5 0

1 0 0 0

1 2 5 0

1 5 0 0

1 7 5 0

2 0 0 0

2 2 5 0

0 2 0 4 0 6 0 80 1 00 1 2 0

(s e c)

(mV

olt)

0

2 50

5 00

7 50

1 0 00

1 2 50

1 5 00

1 7 50

2 0 00

2 2 50

0 2 00 4 0 0 6 0 0 8 0 0 1 0 00 1 2 0 0

(s e c)

(mV

olt)

20 min

C10

C40Conventional GC

C10 C40

2 min

Ultra Fast GC

QC sample (50 ng/µl)

Column: 5 m x 0.32 mm id, 0.25 µm TR-5Temperature Program:40°C (0.3’), 200°C/min to 350°C (0.5’)Injection volume: 1 µl - splitless

18

No more extract re-concentration !

LIQUID EXTRACTION SAMPLE

CLEAN-UP SOLVENT EVAPORATIVE

CONCENTRATION

Ultra Fast GC

ConventionalGC

The sample reconcentration step can be by-passed!

19

ISO 9377-2 (Mod.)

2003: OSPAR proposed a new reference method ISO 9377-2 (Mod.), to get in force from January 2007 in North Sea area

Solvent: n-pentaneRange: C7-C40BTEX have to be separated as well!

Is it still possible to fulfil these specs at high speed of analysis?

YES ! using PTV Injector and Triplus Autosampler

20

Optimized PTV Injector

Split Programmable Temperature Vaporizer (PTV)

• Cool Injection• Prevents in-Needle Discrimination

During Transfer from the Needle to the Injector

• Higher Boiling Point Compounds• Operate PTV independently of

Column at Optimum Cool Temperature for Injection

Permanently Heated Block at Base Avoids Cold Spots for the SampleTransfer to the Column

Sampleevaporationzone

Cold

HotSampletransfer line

21

TriPlus Trio: AS, HS, and SPME

Flexible Sampling Solutions

Standard and Advanced Liquid sampling:

From nano-volumes toLarge Volume techniques(up to 450 µl)

Accurate Headspace sampling:

Zero bench space system based on gas tight syringe approach

SPME (*) technique:

Unprecedented fiber handling robustness to cut sample prep costs

(*) under license from Supelco®

22

TriPlus Technical Overview

• Main Features

- Designed to fully exploit the potentiality of the GC Injectors- AS-HS convertibility;- Easy installation;- Multiple GCs configurations;

• TriPlus AS

• TriPlus HS

• Control software

23

Optimization of Injection : UFGC with ‘Triplus’ Autosampler

Robotic autosampler

• Optimum injection to avoid sample introduction discrimination over wider bp range

• Improved precision

• Cooling of syringe before samplingAvoid losses of light solvents

• Needle solvent Wash technique• Depth of injection control• Injection speed control

24

Ultra Fast GC : PTV Split injection of BTEX in n-Pentane

Column 5m x 0.1 mm id, 0.1 um TR-5

Seconds

20 30 40 50 60 70 80 90 100 110 120 130

Mill

ivol

ts

-250

0

250

500

750

1000

1250

1500

1750

2000

2250

2500

Mill

ivol

ts

-250

0

250

500

750

1000

1250

1500

1750

2000

2250

2500TRACE GC-Channel 1Fluorobenzene + BTEX Mix_New_40C Col tempFluorobenzene + BTEX Mix_New_40C Col temp

NameRetention Time

Ben

zene

Fluo

robe

nzen

e

Tolu

ene

m/p

-Xyl

ene

O-X

ylen

e

Ethy

lben

zene

If the analysis is performed at 40 °C Initial Col Tempa loss of resolution is obtained !

25

Co-solvent addition during injection

Co-solvent addition:

to tune solvent trapping effectto better managing difficult solvents and

difficult solutesto reduce the total amount of solvent

transferred to column and detector

What is a co-solvent ?

A liquid with:

a lower volatility

a different polarity (in some cases)

It is a momentary retention power thatdisappear by evaporation !

26

TriPlus: Software utilities

Needle Solvent wash:selection of solvent vial position and solvent vial depth

27

Co-solvent addition trough the Autosampler syringe during PTVLVI injection at two different liner level

Co-solvent Sample

28

Variation of injection speed and injection level during LVI

Injection speed can be high at the beginning of the

injection and reduced for the rest of the injection

Liner/precolumn conditions are different at the beginning

and during injection

29

PTV-BKF with Co-solvent addition during samplingPAH’s in n-Hexane with iso-Octane

140ul in Hexane only

140ul Hexane+15ul Iso-octane1

2 3 45

6 7

9

8

10

1112 15

14

13 16

12

3 45

6

7 8

910

9

11 12

1314 15

16

30

ON-Column LVI with co-solvent addition during injection

31

Ultra Fast GC : PTV Split injection of BTEX in n-Pentane

Column 5m x 0.1 mm id, 0.1 um TR-5

Seconds

20 30 40 50 60 70 80 90 100 110 120 130

Mill

ivol

ts

-250

0

250

500

750

1000

1250

1500

1750

2000

2250

2500

Mill

ivol

ts

-250

0

250

500

750

1000

1250

1500

1750

2000

2250

2500TRACE GC-Channel 1Fluorobenzene + BTEX Mix_New_40C Col tempFluorobenzene + BTEX Mix_New_40C Col temp

NameRetention Time

Ben

zene

Fluo

robe

nzen

e

Tolu

ene

m/p

-Xyl

ene

O-X

ylen

e

Ethy

lben

zene

If the analysis is performed at 40 °C Initial Col Tempa loss of resolution is obtained !

32

Injection and separation of BTEX (10ng/ul) + Fluorobenzene (20ng/ul) in Pentane using the cryo option for the oven

Seconds

80 82 84 86 88 90 92 94 96 98 100 102 104 106 108

Mill

ivol

ts

4000

5000

6000

7000

8000

9000

10000

11000

12000

13000

14000

Mill

ivol

ts

4000

5000

6000

7000

8000

9000

10000

11000

12000

13000

14000

Benz

ene

Fluo

robe

nzen

e

Tolu

ene

Eth

ylbe

nzen

e

m/p

_Xyl

ene

O-X

ylen

e

TRACE GC-Channel 1Fluorobenzene + BTEX Mix_New002_Fluorobenzene and BTEX Mix_New

Name

Column 5m x 0.1 mm id, 0.1 um TR-5

5°C Initial Column Temp

33

Co-Solvent addition applied during PTV injectionPerfect solvent effect for BTEX at 40°C

Seconds

30 35 40 45 50 55 60 65 70 75 80 85 90

Mill

ivol

ts

0

1000

2000

3000

4000

5000

6000

Mill

ivol

ts

0

1000

2000

3000

4000

5000

6000

Be

nzen

e

Fluo

robe

nzen

e

Tolu

ene

Et

hylb

enze

ne

m/p

_Xyl

ene

O

-Xyl

ene

TRACE GC-Channel 1Fluorobenzene + BTEX Mix_New_40C Col temp_2ul with 1 MTBEFluorobenzene + BTEX Mix_New_40C Col temp_2ul with 1 MTBE

Name

1ul of MTBE added to 2 ul of Standard solution in n-Pentane

40°C Initial Column Temperature !

Column 5m x 0.1 mm id, 0.1 um TR-5

34

Standard Mix BTEX and Hydrocarbons

Column: 5 m x 0.1 mm id, 0.1 µm TR-5Temperature Program:38°C (0.8’), 100°C/min to 350°C (0.5’)Injection volume: 3µl – split flow 20ml/min

< 5 min

C40/C20 > 0.9

35

BTEX and Hydrocarbons separation

36

Mix Real Sample and BTEX in PentanePTV injection with Co-solvent (MTBE)

Seconds

0 20 40 60 80 100 120 140 160 180 200

Mill

ivol

ts

0

500

1000

1500

2000

2500

3000

Mill

ivol

ts

0

500

1000

1500

2000

2500

3000

Benz

ene

Fl

uoro

benz

ene

Tol

uene

Et

hylb

enze

nem

/p_X

ylen

e

O

-Xyl

ene

TRACE GC-Channel 12ul Real Sample in Pentane plus 1ul of MTBE002_2ul Real Sample in Pentane plus 1ul of MTBE

Name

Minutes1.40 1.45 1.50 1.55 1.60 1.65 1.70 1.75 1.80 1.85 1.90

Mill

ivol

ts

3500

4000

4500

5000

5500

6000

6500

7000

7500

Mill

ivol

ts

3500

4000

4500

5000

5500

6000

6500

7000

7500

B

enze

ne

To

luen

e

E

thyl

benz

ene

m/p

_Xyl

ene

O-X

ylen

e

TRACE GC-Channel 1MIX_ BTEX_Real sample_ in C5_ 5C Col Temp001_MIX_ BTEX_Real sample_ in C5_ 5C Col Temp

Name

Column 5m x 0.1 mm id, 0.1 um TR-5

37

Reference Gasoil

Reference Gasoil - 50 ppm

RSD% = 2.2% (10 repetitions)

38

Software: Chrom-Card

A specific application of Chrom-Card allows automatic integration and reporting

• The group peak area C7-C40 is calculated

• The BTEX are individually integrated

Benzene

Toluene

Ethyl-Benzene

m,p-Xylene

o-Xylene

39

ISO 9377-2 (Mod.): Linearity Test

Gasoil Reference Mix - from 2 to 200 ppm

40

Sensitivity

Reference Gasoil

3µl only!

41

System Robustness?

Robustness vs dirty matrices

42

Robustness vs dirty matrices

RSD% Group Peak

After 100 real water extract injections is

(10 runs) = 2.3%

Real Water Extract

43

ISO 9377-2 (Mod.): Conventional capillary GC with LVOC Inj

40 min!!!

50µl injected into a pre-column

Ultra Fast analysis is 10-fold more productive !

Large Volume On Column Injection

Automatic OC LV

44

Conclusions

• The analysis of Total Hydrocarbons in water/soil is carriedout by Ultra Fast GC in 10-fold shorter run time, stillmantaining compliance with ISO 9377-2 (Mod.) and otherofficial methods

• The Ultra Fast method allows to:- Maximize productivity- Grant top level of repeatability, sensitivity and ruggedness