Development of an analytical method for volatiles by solid phase adsorptionanalytical derivatization-solvent elution technique using online SPE-GC/MS system〇Shoya Arakawa, Tomonori Asai, Ryoichi Sasano (AiSTI SCIENCE Co., Ltd.)

1．Solid phase adsorption-analytical derivatization-solvent elution technique
Conditioning

DryingAdsorption

N2 gasDryingDerivatization

N2 gasReagents

Elution ＆ Injection

LineNeedle

Dewater

ElutionInfiltration

Drawing

SPEcartridge

MSTFA/Hexane(1/4), 1 min

2．Experimental method

GC/MSAnalysis

脱水

Headspace volatiles are collected and derivatizedin a SPE cartridge, the entire eluate is injected
into a large volume injection port.

Repeatability (non-derivatization)

2-Methylisoborneol

GeosminSample: Spiked ultrapure waterCoffee powder 1 g
80℃, 1000 rpm, 15 min

Fig 1. Overview of online SPE-GC/MS system
LVI-S250 and SPL-M100（AiSTI SCIENCE）

3-1．Repeatability and Linearity by musty odor

Pretreatment workflow of volatile analysis (trimethylsilylation)

Water 10 mL

Solvent

Heat：80℃, 3 min
Sampling volume: 20 mL
Flow：150 μL/sec

Conditioning
Acetone/Hexane(1/3)
Drying: N2 gas

Concentration: 10 μg/L
Sample volume: 5 mL
Additive: NaCl 2 g
Sampling volume: 20 mL

Extract

Flash-SPE PBX（SDVB* based polymer）

20 mL vial

Flow：150 μL/sec
Injection mode: Large volume injection (①）*SDVB: Stylene divinylbenzene

Drying: N2 gas

Extract 2 mL

GC Oven temp.:
40℃ (4 min) - 20℃/min - 230℃ (10 min)Water 6 mL

Derivatization: MSTFA/hexane(1/4), 1 min

Average: 3,156,403

Average: 2,595,621

NaCl 3 g

Elution: Acetone/Hexane(1/3)

RSD (n=7): 5.4%

RSD (n=7): 6.1%

Injection (the entire eluate)

Setting on the tray

Analysis: GC-MS

Linearity (non-derivatization)
Automated processing
on the system (20 min)Sample: Spiked ultrapure water

2,500

Concentrations: 0.4, 2, 4, 6, 8 μg/L

2,000

Peak area

Sample volume: 5 mL

GC-MS condition

Additive: NaCl 2 g②Volatiles (trimethylsilylation)

Drawing volume: 20 mL

PTV Injector

LVI-S250（AiSTI Science）

LVI-S250（AiSTI Science）

Flow：150 μL/sec

Injector temp.

70℃(0.3 min)-100℃/min-290℃

150℃(0.5 min)-100℃/min-290℃

Injection mode: Large volume injection (①）

GC-MS

7890B + 5977B (Agilent Technologies)

7890B + 5977B (Agilent Technologies)

Split

100 mL/min (70 kPa, 0.3 min)→ Splitless (3 min) → 50 mL/min

GC Oven temp.:
40℃ (4 min) - 20℃/min - 230℃ (10 min)

1:25

Flow mode

Constant flow, 1.4 mL/min

Constant flow, 1.0 mL/min

Pre-column

0.25 mm i.d. × 0.5 m

0.25 mm i.d. × 0.5 m

Column

DB-WAX, 0.25 mm i.d. × 60 m, df=0.25μm

VF-5ms, 0.25 mm i.d. × 30 m, df=0.25 μm

Oven temp.

40℃ (4 min) - 5℃/min - 230℃ (10 min),Total 52.5 min

80℃ (4 min) - 10℃/min - 210℃ - 20℃/min- 310℃ (2 min), Total 24 min
290℃

Ion source temp.

260℃

260℃

Acquisition mode

Scan (m/z 41-400)

Scan (m/z 41-500)

y = 243363x - 47976
R² = 0.9974

R² = 0.9983

1,500
1,000
500

500
0002

468

100

Conc. (μg/L)

2468

10

Conc. (μg/L)

3-2. Applicability and annotated volatiles
Wine

2853

1

11

9

6413

107

Principal component analysis(non-derivatization)y = 192205x - 25771

The system repeatability and sampling linearity were confirmed

3-3．Discrimination test by coffee samples

12

1. Isovareric acid-TMS
2. 3-Ethoxypropanol-TMS
3. Propylene glycol-2TMS
4. Ethyl glycolate-TMS
5. Lactic acid-TMS
6. 2-Furonic acid-TMS
7. Ethyl caprylate
8. Monoethyl succinate-TMS
9. Nonanoic acid-TMS
10. Ethyl caprate
11. Diethyl 2-hydroxyglutarate-TMS
12. Ethyl 3-phenyllactate-TMS
13. Diethyl tartarate-2TMS

Dashisoysauce11032

In non-derivatization method, only MCB showed characteristic group of compounds

Principal component analysis(trimethylsilylation)

2,000

1,000

①Volatiles (non-derivatization)

Geosmin×103

1,500Methods

Transferline temp. 250℃

2-Methylisoborneol

×103

Peak area

VortexPyrazines

481191213

4. Discussions and Conclusion
Advantages of the derivatization method
・Analysis can be performed using the same configuration for metabolome analysis
・Shorter analysis time and high-throughput

Nuts, Roastaroma

Smorky, Woody,
Spicy aroma

56 7

1. Butyric acid-TMS
2. Isovareric acid-TMS
3. Isocaproic acid-TMS
4. 1-Octen-3-ol-TMS
5. 2-Ethylhexanol-TMS
6. o-Cresol-TMS
7. m-Cresol-TMS
8. p-Cresol-TMS
9. Caprylic acid-TMS
10. 4-vinylguaiacol-TMS
11. Hydroxystylene-TMS?
12. Vanillin-TMS?
13. Syringol-TMS

Phenols

Derivatization method showed that pyradines and phenols contributed

Disadvantages of the derivatization method
・Detection of >C3 components is difficult (elution is faster than reagent)・Sensitivity is lower compared to the non-derivatization method + large-volume injection
Future issues
・Establishment of a database of derivatized volatiles
・Simultaneous analysis with taste components (amino acids, organic acids, sugars, etc.)