CHEMICAL ANALYSIS OF EXHALED HUMAN BREATH USING HIGH RESOLUTION MM-WAVE ROTATIONAL SPECTRA

Tianle Guo, Jessica R. Thomas, Daniela R. Branco, Ivan R. MedvedevDepartment of Physics

DAVID DOLSON, Department of ChemistryWright State University, Dayton, OH

HYUN-JOO NAM, Department of Bioengineering, TX,KENNETH O, Electrical Engineering, University of Texas at Dallas, Dallas, TX

Experimental Setup

Continuous Wave THz Spectrometer

Microwave Synthesizer Custom Built

Diode Multipliers Virginia Diodes Heterodyne Reciever, 210~270 GHz

Absorption Cell 2 m long by 4 inches wide (14 L), Large; 2 m long by 1 inches wide (0.875 L), Small

Preconcentrator ENTECH 7100A; Markes Sorbent tubes

Preconcentrator

Absorption Cell(Large)

Custom Built Microwave Synthesizer

Absorption Cell(Small)

MM-WAVE ROTATIONAL Gas Chromatography–Mass Spectrometry

Do no need Calibration. Only need to acquire a library once.

Day to Day calibration

High number of resolution elements 100,000 leads to high specificity

Much lower number of resolution elements 200, leads to possible ‘false positive’ and ‘false negative’

Suitable for lighter polar molecules more accurate results for larger molecules

Young Sophisticated

Our System versus GC-MS

Blood glucose Assessment based in Breath analysis -

Prior Work• Breath acetone(1) and methyl nitrate(2) level were reported linear related to blood-sugar level.

(1)C.N. Tassopoulos. (1969). BREATH-ACETONE AND BLOOD-SUGAR MEASUREMENTS IN DIABETES. the lancet. 293 (7609), p1282-1286.

(2)Galassetti, P. R.. "Exhaled methyl nitrate as a noninvasive marker of hyperglycemia in type 1 diabetes." Proceedings of the National Academy of Sciences: 15613-15618.

• The eventuality of metabolizing glucose and aspartame into Methanol is known from professional literature.

• A higher amount of breath CO in diabetic person was noticed, and there was a positive correlation between exhaled CO levels and the incidence of glycemia.

(3)Paredi, P.. "Exhaled Carbon Monoxide Levels Elevated in Diabetes and Correlated With Glucose Concentration in Blood: A New Test for Monitoring the Disease?." Chest: 1007-1011

• Patients with diabetics may have a higher Breath Isoprene(4)Barker M, Hengst M, Schmid J, et al. Volatile organic compounds in the exhaled breath of young

patients with cystic fibrosis. Eur Respir J 2006;27:929e36.

• Toluene is one of the potential markers used for the diagnosis of diabetes(5)Shin, Jungwoo. "Thin-Wall Assembled SnO2 Fibers Functionalized by Catalytic Pt Nanoparticles and

their Superior Exhaled-Breath-Sensing Properties for the Diagnosis of Diabetes." Advanced Functional Materials 23: p2357-2367.

Analytical Chemical Detection Algorithm

1. Create the spectral libraries•Collect overview spectra of the pure samples at well defined pressures (1 mTorr, 5 mTorr, 10 mTorr)•These overview spectra are then overlaid in order to choose 5 of the strongest lines of each chemical that do not overlap with other chemicals.•The amount of pressure for each chemical used in our library is determined by matching pressure broadening of the library spectra to the breath spectra.

2. Record spectra of the chemicals in breath•Breath/Air samples were then collected into a Tedlar bag/Sorbent tubes •Use preconcentrator/Sorbent tubes to remove major air constituents (O2, N2, H2O, and CO2)•Inject preconcentrated breath into the absorption cell•Record the snippet spectra

3. Perform spectral analysis•Calculate partial pressures of every chemical present in the absorption cell by performing the Least Squares Fitting (LSF) of the mixture spectrum to the library spectrum.•Can get the volumetric dilution of each chemical in the original breath sample based on the volume of the absorption cell and the preconcentration efficiency

Spectra – Example

Breath Collection Method

Tenax TA 35/60, Carborgraph 1TD 40/60, Carboxen 1003 40/60

Bio-VOC Breath sampler127CC Exhaled Breath

Tedlar Bag Vs Sorbent tubes

1. By using Tedlar Bags, we collect all the exhaled

breath. However, most valuable chemicals from

metabolism are in the alveolar volume (last portion of

exhalation). Using Tedlar Bag will lower the sensitivity

and bring contamination from environment.

2. Entech 7100A use cold trap, and high boiling

temperature chemical will be taken away.

3. Tenax TA is a weak sorbent, cannot catch Carbon-

Monoxide .

Entech 7100AWith Tenax TA

Contamination of the cell(Old cell – Large volume)

Black—Baseline(empty)Red—--Breath

Contamination of the cell(New Cell – Small Volume)

Blue—Baseline(empty)Red—--Breath

Comparison of Two Method

Black – Old systemRed – New system

Comparison of Two Method

Black – Old systemRed – New system

Comparison of Two Method

Chemicals Normal Breath Sensitivity(Old) Sensitivity(New)

Ethanol 0 - 1663 ppb 24 ppb 2.4ppb

Methanol 32 - 1684 ppb 8.1 ppb 1.6ppb

Acetone 177 - 3490 ppb 68 ppb 11ppb

Acetaldehyde 0 - 104 ppb 10 ppb 1.5ppb

Chloromethane - 33 ppb 0.12ppb

HCN 4.4 ppb 0.5 ppb 10ppt

Methyl Cyanide 4.4 ppb 12 ppb 80ppt

CO 0~100ppm 16ppb 60ppt

Formalradehyde 40ppb(breath), 100ppb(environment)

14.7ppb 2.6ppb

Methyl Nitrate* 10 - 30 ppt 3 ppb -

Toluene 0-0.1ppb 450 ppb -

Isoprene 50~1000ppb 1200ppb -

Chemicals Currently Studied

Breath Chemicals & Blood Sugar

Experimental Process

•Subject I, female, healthy.•Subject II, Diabetic type 1•breath (500cc) was collected Randomly, (no condition controlled), over several days,

• Breath samples consisted of approximately 2 exhalations.

• Blood Sugar level was collected right after the breath by OneTouch® UltraMini® blood glucose meter.

•Breath spectra was recorded for each sample.

Breath Results – Subject I (non diabetic)

60 70 80 90 100 110 120 130 140 150 1600

0.000000005

0.00000001

0.000000015

0.00000002

0.000000025

0.00000003

0.000000035

0.00000004

0.000000045 Acetaldehyde

60 70 80 90 1001101201301401501600.00E+00

5.00E-09

1.00E-08

1.50E-08

2.00E-08

2.50E-08

Chloromethane

60 70 80 90 100 110 120 130 140 150 1600.00E+00

5.00E-08

1.00E-07

1.50E-07

2.00E-07

2.50E-07

Acetone

60 70 80 90 100 110 120 130 140 150 1600.00E+00

1.00E-09

2.00E-09

3.00E-09

4.00E-09

5.00E-09

6.00E-09

7.00E-09

8.00E-09

HCN

60 70 80 90 1001101201301401501600.00E+00

2.00E-08

4.00E-08

6.00E-08

8.00E-08

1.00E-07

1.20E-07

1.40E-07

1.60E-07

Methanol

60 70 80 90 100 110 120 130 140 150 1600

0.00000005

0.0000001

0.00000015

0.0000002

0.00000025

0.0000003 Ethanol

Breath Results – Subject II (Type 1)

1101201301401501601701801902002100.00E+00

1.00E-08

2.00E-08

3.00E-08

4.00E-08

5.00E-08

6.00E-08

7.00E-08

8.00E-08

9.00E-08

Chloromethane

Glucose Level (mg/dL)

PP

in

bre

ath

110 120 130 140 150 160 170 180 1900.00E+00

1.00E-08

2.00E-08

3.00E-08

4.00E-08

5.00E-08

6.00E-08

7.00E-08

8.00E-08

Acetaldehyde

Glucose Level (mg/dL)

PP

in

bre

ath

110 130 150 170 190 210 2300.00E+00

2.00E+00

4.00E+00

6.00E+00

8.00E+00

1.00E+01

1.20E+01

HCN

Glucose Level (mg/mL)

PP

in

bre

ath

110 130 150 170 190 210 2300.00E+00

2.00E+00

4.00E+00

6.00E+00

8.00E+00

1.00E+01

1.20E+01Acetone

Glucose Level (mg/dL)

PP

in

bre

ath

110 120 130 140 150 160 170 180 1900.00E+00

5.00E-08

1.00E-07

1.50E-07

2.00E-07

2.50E-07

3.00E-07

3.50E-07

Methanol

Glucose Level (mg/dL)

PP

in

bre

ath

Breath Results – Subject II at high levels

• at the high blood glucose level, we found a possible negative linear relationship in Acetone, Acetaldehyde, and Methanol.

130 150 170 190 210 2300.00E+00

1.00E-08

2.00E-08

3.00E-08

4.00E-08

5.00E-08

6.00E-08

7.00E-08

8.00E-08

f(x) = − 7.12437633642195E-10 x + 1.81432430506058E-07R² = 0.72286788939204

Acetaldehyde

Acetaldehye

Linear (Acetaldehye)

130 150 170 190 210 2300.00E+00

1.00E-07

2.00E-07

3.00E-07

4.00E-07

5.00E-07

6.00E-07

7.00E-07

f(x) = − 9.6872416250891E-09 x + 2.09763435495367E-06R² = 0.804516040887746

Acetone

Acetone

Linear (Acetone)

130 150 170 190 210 2300.00E+00

5.00E-08

1.00E-07

1.50E-07

2.00E-07

2.50E-07

3.00E-07

3.50E-07

f(x) = − 4.89272986457591E-09 x + 1.05678047042053E-06R² = 0.947082337251943

Methanol

Methanol

Linear (Methanol)

Type 2 Diabeticwith New Cell, Strong Sorbent tube

NAME AMOUNT IN BREATH/ppb

Methyl Cynaide 9.86±0.08

Chloromethane 0.83±0.01

Acetaldehyde 33.6±1.5

Acetone 46.7±8.2

HCN 6.99±0.02

Ethanol 33.8±2.4

Methanol 61.5±2.6

CO 13.5±0.1

Formaldehyde 71.8±0.3

Conclusion & Path Forward

• We now can see 9 chemicals which are potentially related to diabetes and blood glucose level. We successfully detected CO and Formaldehyde and improved the sensitivity of our system by a factor of 10.

• The blood glucose experiment is still in progress. Our preliminary results show that there may exist a relationship between blood glucose level and concentrations of acetone, acetaldehyde and methanol.

Conclusion

Path forward

• Improve Sensitivity and extend the current chemical list.

• Collect more data with the new system• Conduct a more controlled experiment on blood glucose level. (overnight fasting,

food)

Thank you