The Importance of Peak Deconvolution with ChromaTOF for ... and... · The Importance of Peak Deconvolution with ChromaTOF for Resolving Flavor and Odor Problems For Leco Corporation

The Importance of Peak Deconvolution

with ChromaTOF

for Resolving Flavor and Odor Problems

For Leco Corporation

May 17, 2012

Ray Marsili

Marsili Consulting Group

www.marsiliconsulting.com

Overview

Musty taint in casein powder

Mold metabolite profiling – a chemotaxonomic study

Floral fragrance profiling

Off-flavor determination in a Mojito beverage mix

Off-flavors in beer

2

Automated Extraction from Liquid Samples

The GERSTEL Twister

Magnetic core, sealed in glass and coated with PDMS

SPME : max. 0.5 µl

l = 10 mm, df = 0.5 mm

df = 1.0 mm

l = 20 mm, df = 0.5 mm

df = 1.0 mm

24 µl

63 µl

47 µl

126 µl

3

The GERSTEL Twister

Same principle as liquid/liquid extraction

– Extraction is based on sorption

– Predictable recovery due to log Ko/w

PDMS sorbent

– Highly inert

– Retains no water

– Selectivity eliminates polar matrix interferences

Desorption with TDS or TDU

– Extremely low detection limits (ppt to ppq)

Stir Bar Sorptive Extraction (SBSE)

[a.k.a. Gum Phase Extraction (GPE)] 4

The GERSTEL Twister

Simple and Efficient Extraction

Stir 1hr to overnight

Desorb Twister in TDS / TDU for highest sensitivity

Perform HPLC analysis for thermally labile compounds extracted by Twister

5

Problem: Two instances of TCA contamination of casein powder and one

instance of TBA contamination of casein powder occurred in summer of 2007.

Tainted (musty) caseins were used to make nutritional beverages. Several law

suits resulted.

Cl

OH

Cl

Cl

O

Cl Cl

Cl

Microbial (i.e., fungal

enzymatic) o-methylation

to form the strong musty

trichloroanisole from the

trichlorophenol.

From pesticides and

wood preservatives

Musty Taint in Casein Powder:

Trihaloanisole Contamination

Marsili Consulting Group 4/19/08

6

chlorophenol O-

methyltransferase

Odor thresholds for TCAs

and TBAs are 0.1 – 2.0 ng/L

400 600 800 1000 1200 1400 1600 1800 2000Time (s)TIC

1gm musty casein + 25 mL water, stir 30 min @ RT;

SBSE for 3 hr with 2 cm x 0.5 mm Twister®

Musty Taint

in Casein Powder


7

Finding chloroanisoles in the chromatogram…

400 600 800 1000 1200 1400Time (s)212 195 161 196

2,4-dichloroanisole

2,4,6-trichloroanisole

7ppb

2,3,6-

trichloroanisole +

more!

Musty Taint

in Casein Powder


8

The value of peak deconvolution…

400 600 800 1000 1200 1400Time (s)212 195 161 196

1196 1198 1200 1202 1204 1206Time (s)212 195 161 196

2,4,6-trichlorophenol


butyl butanoate


2,4-dichloroanisole

Musty Taint

in Casein Powder


9

TBA and TBAd Spike (133 ppb) in Musty Casein

885 890 895 900 905 910 915 920 9250

2000

4000

6000

8000

10000

12000

14000

16000

18000

Time (s)

351 344

2,4,6-tribromoanisole

(m/z 346)

TBAd spike

(m/z 351)

(mainlib) Benzene, 1,3,5-tribromo-2-methoxy-

80 100 120 140 160 180 200 220 240 260 280 300 320 340 3600

50

100

81 117 130

141

155

197

222235

250

303

329 346

O

Br Br

Br

Technique is called SIDA (Stable

Isotope Dilution Analysis). “SIDA is

arguably the most accurate technique

for quantitative determination of

organic compounds.” (Alan D. Harmon

in Flavor, Fragrance and Odor

Analysis.)

Musty Taint

in Casein Powder

351 346

10

TBAd Standard Curve in Control Casein TBAd spikes in 3g Casein Powder

y = 0.0000491x

R 2 = 0.9943122

0

2 0

4 0

6 0

8 0

10 0

12 0

0 50 0 0 0 0 10 0 0 0 0 0 150 0 0 0 0 2 0 0 0 0 0 0 2 50 0 0 0 0

Peak Area @351 amu

uL

Sp

ike (

0.0

2u

g/u

L T

BA

d)

667 ppb

20 ppb

Musty Taint

in Casein Powder


11

Techniques for

Analyzing

Mold Metabolites

Ray Marsili

www.marsiliconsulting.com

12

http://upload.wikimedia.org/wikipedia/commons/e/e7/Ascomycetes.jpg

Kingdom Phylum Class Order Family Genus Species Type

Fungi Deuteromycota Eurotiomycetes Moniliales Moniliaceae Penicillium roqueforti cheese mold

Fungi Deuteromycota Eurotiomycetes Moniliales Moniliaceae Penicillium camemberti cheese mold

Fungi Deuteromycota Eurotiomycetes Moniliales Moniliaceae Penicillium italicum plant mold

Fungi Zygomycota Zygomycetes Mucorales Mucoraceae Rhizopus stolonifer filamentous mold

Fungi Basidiomycota Homobasidiomycetes Agaricales Agaricaceae Coprinus cinereus mushroom

Fungi Ascomycota Ascomycetes Sphaeriales Sordariaceae Sordaria fimicola microfungus

Protocista Heterkonta Oomycotea Saprolegniales Saprolegniaceae Saprolegnia sp. water mold

Taxonomic Classification of Penicillium Species

and Outgroups

Can we Distinguish Pencillium Species from Outgroups

Based on GC-TOFMS Metabolite Profiles?

Mold Metabolite Profiling

From Petri Dish Cultures


13

Fungal Metabolites by HSSE

Adsorbent-packed thermal

desorption tube inside of lid

Normal lab

stir bar on

outside of lid GERSTEL

Twister on

inside of lid Petri dish lid

Petri dish bottom;

mold growth on agar.

Previous Method (T.O. Larsen and J.C. Frisvad, 1994)

New Twister HSSE Method

Wire screen

14

Outgroups Penicillium Species

Analyte Cas No.

#1

S

#2

S

#3

S

#4

S

#5

P

#6

P

#7

S

#8

P

#9

S

#10

P

#11

S

2-Heptenal, (E)- 18829-55-5 0 0 0 0 0 x x x x x x

Decane 124-18-5 xxx xxx xxx xxx xxx 0 xxx 0 0 0 xxx

Phenol 108-95-2 0 0 0 0 0 xx 0 0 x x 0

Pentanoic acid 109-52-4 0 0 xxx 0 x 0 xxx 0 0 0 0

Nonane, 2,6-dimethyl- 17302-28-2 xxx 0 xxx 0 0 0 0 0 0 0 0

trans-3-Caren-2-ol 0-00-0 0 0 0 xx 0 0 0 0 0 0 0

3-Pentanol 584-02-1 xxx 0 0 0 0 0 xx 0 0 0 xx

Decane, 4-methyl- 2847-72-5 xxx xxx xxx xxx xxx 0 0 0 0 0 0

Thujone 546-80-5 0 x 0 0 0 0 0 0 0 0 0

cis-Geraniol 106-25-2 0 0 0 x 0 0 0 0 0 0 0

Undecane 1120-21-4 xxx xxx xxx xxx xxx 0 x 0 x 0 x

Linalool 78-70-6 xxx 0 0 0 0 0 x 0 x xx xx

Phenylethyl Alcohol 60-12-8 0 0 xxx xxx xxx x x 0 0 0 xx

Megastigma-4,6(E),8(Z)-triene 71186-24-8 xxx x 0 0 0 0 0 0 0 0 0



#1=Coprinus cinereus; #2 =Saprolegnia Sp.; #3=Rhizopus stolonifer; #4&#5= Sordaria fimricola;

#6&#7= Penicillium italicum; #8&#9=Penicillium camemberti; #10&11= Penicillium roqueforti

S=Sabouraud Dex; P=Potato Dex

15

Outgroups Penicillium Species

Analyte Cas No. #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11

a-Gurjunene 489-40-7 xxx 0 0 0 0 0 0 0 0 0 0

Neoclovene 4545-68-0 xx 0 0 0 0 0 0 0 0 0 0

Thujopsene-(I2) 0-00-0 0 xx 0 0 0 0 0 0 0 0 0

Indole 120-72-9 0 0 0 0 0 x 0 0 0 x 0

Chamigrene 18431-82-8 xxx 0 0 0 0 0 0 0 0 0 0

(+)-Sativene 3650-28-0 xxx xxx 0 0 0 0 0 0 0 0 0

Di-epi-alpha-cedrene- 21996-77-0 xxx x 0 0 0 0 0 0 0 0 0

Viridiflorol 552-02-3 xxx 0 0 0 0 0 0 0 0 0 0

Santene 529-16-8 xxx 0 0 0 0 0 0 0 0 0 0

Allo-Aromadendrene 25246-27-9 xxx 0 0 0 0 0 0 0 0 0 0

beta-Caryophyllene 87-44-5 xxx 0 0 0 0 0 0 0 0 xxx 0

Cedrene 11028-42-5 x 0 0 0 0 0 0 0 0 0 0

Elemene 339154-91-5 x 0 0 0 0 0 0 0 x 0 0

alpha-Caryophyllene 6753-98-6 xx x 0 0 0 0 0 x 0 0 0

a-Bergamotene 17699-05-7 0 0 0 0 0 x x x x 0 x

Caryophyleine-(I3) 136296-37-2 0 0 0 0 0 0 0 0 x xxx 0

cis-a-Bisabolene 29837-07-8 xxx x 0 0 0 0 0 0 0 xxx 0

Aristolochene 0-00-0 xxx x 0 0 0 0 0 0 0 x x



16

Chemical Cas No. Factor1 Factor2 Factor3

Decane 124-18-5 0.2790 0.2370 -0.2963

4-Methyl decane 2847-72-5 0.0718 -0.0133 -0.0219

Undecane 1120-21-4 0.2972 0.6110 -0.5162

Linalool 78-70-6 0.1151 -0.0462 0.0378

Phenylethyl alcohol 60-12-8 -0.0002 0.0445 -0.1611

1-Propanone, 1-(5-methyl-2-furanyl)- 10599-69-6 0.0009 0.0385 0.0418

2-Methyl undecane 7045-71-8 0.0133 0.0367 -0.0347

(+)-Sativene 3650-28-0 0.1398 -0.0240 0.0634

2-Cyclohexen-1-one, 4-ethyl-4-methyl- 17429-32-2 0.8560 -0.2926 0.2323

1H-Indene, 1-ethyloctahydro-7a-methyl- 56324-71-1 0.0155 0.6317 0.6859

Methyl cinnamate 103-26-4 0.0269 0.1901 0.2206

Caryophyleine-(I3) 136296-37-2 -0.0535 -0.0954 0.1181

Dodecanoic acid 143-07-7 -0.0478 -0.0563 -0.0037

Phenol, 3-pentadecyl- 501-24-6 0.0022 0.0795 0.0655

PCA Loadings Values for Factors 1, 2 and 3

for Chemicals Most Influential to Clustering




17

200 300 400 500 600 700 800Time (s)

TIC

1

B

2

3

4 5

6

7

8

9 B

10

11

12

13

14

15

16

17

19

18

20

(1) acetic acid (agar bkgd); (2) 3-octanone; (3) decane; (4) 2,6-dimethyl nonane; (5) 2-methyl decane;

(6) 3-methyl decane; (7) undecane; (8) linalool; (9) octanoic acid, ethyl ester (agar bkgd); (10)

decanal (agar bkgd); (11) megastigma-4,6(E),8(Z)-triene; (12) a-gurjunene; (13) chamigrene; (14)

longifolene-(V4); (15) aristolochene; (16) sativene + di-epi-a-cedrene; (17) 4-ethyl-4methyl-2-

cylcohexen-1-one; (18) caryophyllene; (19) allo-aromadendrene; (20) cis-a-bisabolene; (B)

polysiloxane peak from Twister.



Sample Chromatogram: Coprinus

cinereus on S-Dex


18

692 694 696 698 700 702 704 706

600000

800000

1e+006

1.2e+006

1.4e+006

1.6e+006

1.8e+006

2e+006

Time (s)TIC

692 694 696 698 700 702 704 706

5000

10000

15000

20000

25000

30000

35000

40000

45000

Time (s)161 94 175

540 542 543 544 545 541

Peak Identification

540=2-pinen-10-ol;

541=viridiflorol;

542=caryophyllene;

543=elemene;

544=santene;

545=isolongifolene

(A)

(B)

(A) TIC of Coprinus cinereus

(S-Dex) from 691s to 707s

and (B) the same region of

the Coprinus cinereus

chromatogram after peak

deconvolution.

The Peak Deconvolution

Advantage


19 TIC

PCA 2D Scores Plot of Peak Area Data

Penicillium

Groups

Outgroups

PCA two-dimensional scores plot for peak area data (118 analytes) after mean

centering preprocessing was applied. Software: Pirouette, Infometrix Inc.




20

PCA 2D Scores Plot of Peak Area Data

Magnified View of

Penicillium Groups

S-Dex

PCA two-dimensional scores plot for peak area data after meancentering

preprocessing was applied. Software: Pirouette, Infometrix Inc.




P-Dex

21

What We Know

About Flower Scents

Amounts and types of volatiles vary…

• Live vs. cut flowers

• Over a 24-hr period (flowers have biorhythm geared to attract pollinators)

• Age of the plant

• Soil, topography and climate (like wine)

22

GERSTEL PDMS Foam

Desorption Tube (Stainless steel cap removed during iris extraction)

23

PDMS Foam Tube Inserted Into Purple Bearded

Iris During Fragrance Extraction 24

Automated Analysis of PDMS Foam Tubes with

GERSTEL TDU and MPS2

(Scent-Exposed Tubes Placed in Storage Tray)

• MPS 2 fitted with Twister Option

• Analyze up to 98 PDMS foam

tubes automatically

• PDMS foam tubes stored with

liners in storage tray

• Sealed compartments

- No loss of analytes

- No contamination

25

PDMS Foam Tubes Automatically Transferred by GERSTEL

MPS2 from Storage Tray to GERSTEL TDU for Desorption

Prior to GC-TOFMS Analysis 26

PDMS Foam Iris Extract Compared to Duplicate

Analyses of Blank PDMS Foam Tube Extractions of

Garden Air (30 min @ 120 mL/min)

200 400 600 800 1000 1200 1400 1600 1800

1e+007

2e+007

3e+007

4e+007

5e+007

Time (s)

TIC PDMS Foam Blank T1 TIC PDMS Foam Blank T2TIC Iris Scent PDMS Foam 30 min T2

PDMS Extract of Iris Fragrance

PDMS Extract of Garden Air (Blank, Trial 1)

PDMS Extract of Garden Air (Blank, Trial 2)

TIC

27

Tenax TA

PDMS Foam

(Both extractions for 30 min @ 120 mL/min)

Comparison of Extraction with Tenax TA and PDMS Foam

200 400 600 800 1000 1200 1400 1600

5e+006

1e+007

1.5e+007

2e+007

2.5e+007

3e+007

Time (s)

TIC Iris Scent Tenax 30 min T2 TIC Iris Scent PDMS Foam 30 min T2

TIC

Tenax TA

PDMS Foam

28

Prior to Peak Deconvolution: Iris Scent Extract by PDMS Foam

The region of chromatogram (TIC) from 730 sec to 735 sec appears to contain two

partially resolved peaks. However, the Pegasus ChromaTOF software indicates

seven detectable peaks in this region of the chromatogram.

730 731 732 733 734 735 736

1.6e+006

1.8e+006

2e+006

2.2e+006

2.4e+006

2.6e+006

2.8e+006

3e+006

3.2e+006

3.4e+006

Time (s)

565 566 567 568 569 570 571

TIC

29

After Peak Deconvolution: Iris Scent Extract by PDMS Foam 565=4’-tert-

butyl acetophenone; 566=bergamotene; 567=2,4,7,9-tetramethyl-5-decyn-4,7-diol;

568=blank (from a polysiloxane from PDMS); 569=tridecanoic acid, methyl ester;

570=valeric acid, 3,5-dihydroxy-2,4-dimethyl, lactone; 571=1,2-dimethyl naphthalene

730 731 732 733 734 735 736

20000

40000

60000

80000

100000

120000

140000

160000

180000

Time (s)

565 566 567 568 569 570 571

85 161 93 109 73 71 74

30

Prior to Peak Deconvolution: Iris Scent Extract by PDMS Foam

The region of the chromatogram (TIC) from 600 sec to 608 sec

appears to contain two partially resolved peaks.

602 604 606 608 610

2.5e+006

5e+006

7.5e+006

1e+007

1.25e+007

1.5e+007

1.75e+007

2e+007

2.25e+007

2.5e+007

Time (s)

430 431432 433 434 435 436 437438 439 440

TIC

31

After Peak Deconvolution: Iris Scent Extract by PDMS Foam

431=t-geraniol; 432=oxalic acid, allyl ethyl ester; 433=4-hydroxy-2-

methylbenzaldehyde; 434=c-geraniol; 435=cyclohexadiene-1-methanol, 4-

(1methylethyl); 436=6-octenoic acid, 3,7-dimethyl, methyl ester; 437=t-tagetone;

438=2,3,6-trimethyl decane

601 602 603 604 605 606 607 608 609

50000

100000

150000

200000

250000

300000

Time (s)

431 432 433 434 435 436 437 438 439

46 69 74 100 119 135 141163 193

32

Figure 12(A): Peak Deconvolution of Isoeugenol in Iris Scent

Chemicals Analyzed by PDMS Foam GC-TOFMS 515=3-methyl-3-(1-ethoxyethoxy)-1-butene; 516=4-methyl tridecane;

517=4’methoxy acetophenone; 518= 8-octadecen-1-ol acetate; 519=mercaptoacetic

acid, bis(trimethylsilyl) background peak; 520=isoeugenol; 521=3-methyl dodecane

682 683 684 685 686 687 6880

5000

10000

15000

20000

25000

Time (s)

515 516517 518 520 521

164 99 73 84 223 135

33

Peak Deconvolution for Isoeugenol Showing

caliper, true and library mass spectra

20 40 60 80 100 120 140 160 180 200 220 240 260 280 300

43 57 71 85 99 164 113 131

Caliper - sample "Iris Scent PDMS Foam 30 min T2", 686.9 s to 686.9 s - ( 0 s to 0 s + 0 s to 0 s )

20 40 60 80 100 120 140 160 180 200 220 240 260 280 300

55 77 164 41 103 91 149 131 182 284

Peak True - sample "Iris Scent PDMS Foam 30 min T2", peak 520, at 686.9 s

20 40 60 80 100 120 140 160 180 200 220 240 260 280 300

164 77 149 91 103 55 131 39 27

Library Hit - similarity 759, "Isoeugenol"

34

200 400 600 800 1000Time (s)TIC

Complaint Mojito Beverage Mix

Mojito is a Cuban Cocktail containing white rum, sugar, lime juice,

sparkling water and mint. SPME GC-TOFMS TIC is complex.

TIC

35

Complaint Mojito Beverage Mix

Degradation/conversion of citral (acid hydrolysis over time) into p-

methyl-acetophenone, p-cresol and 9-hydroperoxy-p-cymene.

OH

O

OH

H+

-H2O

O

OH

OOH

citral

+

p-menthadien-8-olsautoxidation

p-mentha-1,4(8),5-triene

p-methyl-acetophenone

+ +

p-cresol 8-hydroperoxy-p-cymene

36

Complaint Mojito Beverage Mix: Carvone

from Acid Catalyzed Reaction of Limonene

50 100 150 200 250 300 350 400

500

1000 69

41

93 123

Peak True - sample "Complaint Mojito", peak 293, at 783.25 s

50 100 150 200 250 300 350 400

500

1000 69

41

93 123

Library Hit - similarity 936, "Geraniol"

50 100 150 200 250 300 350 400

500

1000 82

54

108

150

Peak True - sample "Complaint Mojito", peak 296, at 785 s

50 100 150 200 250 300 350 400

500

1000 82

54 108 39

150

Library Hit - similarity 947, "L(-)-Carvone"

Geraniol Carvone

37

Off-Flavors in Beer: TIC of SBSE &

HSSE (Control Beer)

200 400 600 800 1000 1200 1400 1600

5e+006

1e+007

1.5e+007

2e+007

2.5e+007

3e+007

Time (s)TIC

200 400 600 800 1000 1200 1400 1600 1800

5e+006

1e+007

1.5e+007

2e+007

2.5e+007

3e+007

Time (s)TIC

HSSE

(Headspace)

SBSE

(Liquid Phase)

38

Six Standards in the 0 – 200 ppb

Range (in Imitation Beer)

Standard Compound CLS P&T HSSE SBSE

Pentanal 0.9998 0.9930 0.9172 0.9997

Hexanal 0.9572 0.9779 0.9959 0.9426

Furfural 0.8664 0.9952 NL 0.9423

1-Butanol, 3-methyl-, acetate 0.7875 0.9532 0.9973 0.9929

Methional 0.8582 ND ND 0.9943

Hexanoic acid, ethyl ester 0.9936 0.9911 0.9252 0.9964

Octanal 0.9954 0.9885 0.9991 0.9972

Benzeneacetaldehyde 0.9985 0.9977 0.9962 0.9996

Nonanal 0.9971 0.9898 0.9989 0.9995

Phenyl ethyl alcohol NL NL NL 0.9796

2-Nonenal, (E)- 0.9916 0.9906 0.9993 0.9997

Ethyl octanoate 0.9980 0.9833 0.9695 0.9559

Decanal 0.9090 0.8598 0.9995 0.9837

Ethyl decanoate 0.8601 0.9571 0.9858 0.9935

Average R2: 0.9394 0.9731 0.9803 0.9841

39

Chemical Changes in Light-Abused

and Heat-Abused Beers

Chemical

CAS No.

R.T

(s)

Quant

Mass

Taste

Threshold

(ppb)

Change vs.

Control

(Fresh) Beer

Light-

Abused

Heat-

Abused

Dimethyl disulfide 624-92-0 174 94 0.06-30a ↑

Dimethyl trisulfide 3658-80-8 361 126 3a ↑

Benzeneacetaldehyde 122-78-1 425 91 1600b ↑

Furfural 98-01-1 249 96 150000b Slt ↑ ↑

Ethyl 3-pyridinecarboxylate 614-18-6 597 106 --- ↑

β-Damascenone 23726-93-4 711 121 0.009a Slt ↓ ↑

Furfuryl ethyl ether 4437-22-3 294 81 6b ↑

Benzeneacetic acid, et ester 101-97-3 597 91 --- ↑

Furyl hydroxymethyl ketone 17678-19-2 465 95 --- ↑

2,4-Dodecadienal, (E,E)- 21662-16-8 513 81 --- Slt ↑

Octanal 124-13-0 384 84 45a ↑

Nonanal 124-19-6 473 56 12a ↑

aTaste threshold measured in water bTaste threshold measured in American style beer

40

b-Damascenone in Beer Before

and After Peak Deconvolution

680 700 720 740 760 780 800 820

5e+006

1e+007

1.5e+007

2e+007

2.5e+007

Time (s)TIC

708 709 710 711 712 713

2e+006

4e+006

6e+006

8e+006

1e+007

1.2e+007

1.4e+007

1.6e+007

1.8e+007

Time (s)TIC

708 709 710 711 712 713

100000

200000

300000

400000

500000

600000

700000

800000

900000

Time (s)121 88 112

Ethyl 9-decenoate

+ b-Damascenone

coeluting

Eth

yl

9-d

ec

en

oa

te

b-D

am

ascen

on

e

b-D

am

as

ce

no

ne

TIC

TIC

700 740 780

708s 710 712

m/z 121

m/z 88

m/z 112

708s 710 712

41

Furfuryl Ethyl Ether in Beer Before

and After Peak Deconvolution

240 260 280 300 320 340 360 380

1e+006

1.5e+006

2e+006

2.5e+006

3e+006

3.5e+006

4e+006

4.5e+006

5e+006

Time (s)TIC

290 295 300 305 310

1e+006

1.2e+006

1.4e+006

1.6e+006

1.8e+006

Time (s)TIC

290 292 294 296 298 300 302

50000

100000

150000

200000

250000

300000

350000

400000

Time (s)81 43 41 53 42 82 44 45

Furfuryl ethyl

ether

TIC

After Deconvolution Before Deconvolution

1 2 3 4

Four Coeluters

(1) Ethyl pentanoate

(2) Heptanal

(3) Furfuryl ethyl ether

(4) 4-Penten-1-yl acetate

42

Spectral Bias (Skewing)

60 80 100 120 1400

250

500

750

1000

Rel. A

bund.

m/z

60 80 100 120 1400

250

500

750

1000

Rel. A

bu

nd

.

m/z

60 80 100 120 1400

250

500

750

1000

Rel. A

bu

nd

.

m/z

42.5 43.0 43.50

2000

4000

6000

8000

Inte

nsity

Time (sec)

42.5 43.0 43.50

2000

4000

6000

8000

Inte

nsity

Time (sec)

42.5 43.0 43.50

2000

4000

6000

8000

Inte

nsity

Time (sec)

60 80 100 120 1400

250

500

750

1000R

el. A

bu

nd

.

m/z

60 80 100 120 1400

250

500

750

1000

Rel. A

bu

nd

.

m/z

60 80 100 120 1400

250

500

750

1000

Rel. A

bu

nd

.

m/z

GC Peak TOFMS Scanning MS

43

Spectral Acquisition Rate

Peak definition is very poor.

1 Spectra/sec

44


Typical scanning instrument rate

Automated peak find is not possible.

2 Spectra/sec

45

Spectral Acquistion Rate

5 peaks located

5 Spectra/sec

46


6 peaks located

10 Spectra/sec

47


8 peaks located

20 Spectra/sec

48

Metolachlor 238

Malathion 158

Fenthion 278

Chlorpyrifos 199

Parathion 291

DCPA 301

Cyanazine 68

Isodrin 193

Trichloronat 269


All 9 peaks located

40 Spectra/sec

49

Why Leco GC-TOFMS for Peak

Deconvolution?

New sample extraction techniques result in high extraction recoveries and more complex chromatograms with overlapping peaks.

Best peak deconvolution with:

o An array detector like TOF with no MS skewing.

o High data density per chromatographic peak (e.g., 40 spectra/sec).

Leco TOFMS provides high sensitivity and peak deconvolution offers advantages of improved mass spectral matching and more accurate peak area determinations.

ChromaTOF auto peak find saves time.

50

Thank you For your Time and Attention

For More Information Contact:

LECO Corporation – www.leco.com

3000 Lakeview Ave.

St. Joseph, MI 49085

Phone: 269-985-5714

Email: [email protected]

Documents

The Importance of Peak Deconvolution with ChromaTOF for ... and... · The Importance of Peak Deconvolution with ChromaTOF for Resolving Flavor and Odor Problems For Leco Corporation