CHEMICAL ANALYSIS OF EXHALED HUMAN BREATH USING HIGH
CHEMICAL ANALYSIS OF EXHALED HUMAN BREATH USING HIGH RESOLUTION MM-WAVE ROTATIONAL SPECTRA Tianle Guo, Jessica R. Thomas, Daniela R. Branco, Ivan R. Medvedev Department of Physics DAVID DOLSON, Department of Chemistry Wright State University, Dayton, OH HYUN-JOO NAM, Department of Bioengineering, TX, KENNETH O, Electrical Engineering, University of Texas at 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 7100 A; Markes Sorbent tubes Preconcentrator Custom Built Microwave Synthesizer Absorption Cell(Small) Absorption Cell(Large)
Our System versus GC-MS 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
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), p 1282 -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 Concentration in Blood: A New Test for Monitoring the Disease? . " Chest: 1007 -1011 • Glucose 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: 929 e 36. • Toluene is one of the potential markers used for the diagnosis of diabetes (5)Shin, Jungwoo. "Thin-Wall Assembled Sn. O 2 Fibers Functionalized by Catalytic Pt Nanoparticles and their Superior Exhaled-Breath-Sensing Properties for the Diagnosis of Diabetes. " Advanced Functional Materials 23: p 2357 -2367.
Analytical Chemical Detection Algorithm 1. Create the spectral libraries • Collect overview spectra of the pure samples at well defined pressures (1 m. Torr, 5 m. Torr, 10 m. Torr) • 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 (O 2, N 2, H 2 O, and CO 2) • 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 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 7100 A use cold trap, and high boiling temperature chemical will be taken away. 3. Tenax TA is a weak sorbent, cannot catch Carbon. Monoxide. Tenax TA 35/60, Carborgraph 1 TD 40/60, Carboxen 1003 40/60 Entech 7100 A With Tenax TA Bio-VOC Breath sampler 127 CC Exhaled Breath
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 system Red – New system
Comparison of Two Method Black – Old system Red – New system
Comparison of Two Method
Chemicals Currently Studied Chemicals Normal Breath Sensitivity(Old) Sensitivity(New) Ethanol 0 - 1663 ppb 24 ppb 2. 4 ppb Methanol 32 - 1684 ppb 8. 1 ppb 1. 6 ppb Acetone 177 - 3490 ppb 68 ppb 11 ppb Acetaldehyde 0 - 104 ppb 10 ppb 1. 5 ppb Chloromethane - 33 ppb 0. 12 ppb HCN 4. 4 ppb 0. 5 ppb 10 ppt Methyl Cyanide 4. 4 ppb 12 ppb 80 ppt CO 0~100 ppm 16 ppb 60 ppt Formalradehyde 40 ppb(breath), 100 ppb(environment) 14. 7 ppb 2. 6 ppb Methyl Nitrate* 10 - 30 ppt 3 ppb - Toluene 0 -0. 1 ppb 450 ppb - Isoprene 50~1000 ppb 1200 ppb -
Breath Chemicals & Blood Sugar Experimental Process • Subject I, female, healthy. • Subject II, Diabetic type 1 • breath (500 cc) 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 One. Touch® Ultra. Mini® blood glucose meter. • Breath spectra was recorded for each sample.
Breath Results – Subject I (non diabetic) Chloromethane Acetaldehyde 5 E-08 2. 50 E-08 Acetone 2. 50 E-07 4. 5 E-08 4 E-08 2. 00 E-07 3. 5 E-08 3 E-08 1. 50 E-07 2. 5 E-08 2 E-08 1. 00 E-07 1. 5 E-08 5. 00 E-09 5. 00 E-08 1 E-08 5 E-09 0. 00 E+00 60 80 100 120 140 160 0. 00 E+00 0 60 110 HCN 60 160 Methanol 1. 60 E-07 7. 00 E-09 1. 40 E-07 6. 00 E-09 1. 20 E-07 5. 00 E-09 1. 00 E-07 4. 00 E-09 8. 00 E-08 1. 5 E-07 3. 00 E-09 6. 00 E-08 1 E-07 2. 00 E-09 4. 00 E-08 60 80 100 120 140 160 2 E-07 5 E-08 0. 00 E+00 120 2. 5 E-07 2. 00 E-08 1. 00 E-09 100 Ethanol 3 E-07 8. 00 E-09 80 60 80 100 120 140 160 0 60 110 160
Breath Results – Subject II (Type 1) Chloromethane Acetaldehyde 1. 80 E-07 2. 50 E-06 2. 00 E-07 2. 00 E-06 Acetone PP in breath 1. 40 E-07 1. 20 E-07 1. 00 E-07 8. 00 E-08 6. 00 E-08 4. 00 E-08 PP in breath 1. 60 E-07 1. 50 E-07 1. 00 E-07 1. 50 E-06 1. 00 E-06 5. 00 E-07 5. 00 E-08 2. 00 E-08 110 160 Glucose Level (mg/d. L) 110 210 HCN 3. 50 E-08 PP in breath 3. 00 E-08 2. 50 E-08 2. 00 E-08 1. 50 E-08 1. 00 E-08 5. 00 E-09 0. 00 E+00 110 160 210 Glucose Level (mg/m. L) 160 Glucose Level (mg/d. L) 210 Methanol 4. 00 E-08 PP in breath 0. 00 E+00 5. 00 E-07 4. 50 E-07 4. 00 E-07 3. 50 E-07 3. 00 E-07 2. 50 E-07 2. 00 E-07 1. 50 E-07 1. 00 E-07 5. 00 E-08 0. 00 E+00 110 130 150 170 190 210 230 Glucose Level (mg/d. L) 110 160 Glucose Level (mg/d. L) 210
Breath Results – Subject II at high levels Acetone 8. 00 E-07 • at the high blood glucose level, we found a possible negative linear relationship in Acetone, Acetaldehyde, and Methanol. 7. 00 E-07 6. 00 E-07 5. 00 E-07 4. 00 E-07 Acetone 3. 00 E-07 Linear(Acetone) 2. 00 E-07 R 2 = 0. 8045 1. 00 E-07 0. 00 E+00 130 150 170 190 210 230 Acetaldehyde 9. 00 E-08 8. 00 E-08 7. 00 E-08 6. 00 E-08 5. 00 E-08 4. 00 E-08 3. 00 E-08 2. 00 E-08 1. 00 E-08 0. 00 E+00 130 150 170 190 210 230 Methanol 3. 50 E-07 3. 00 E-07 Acetaldehye 2. 50 E-07 2. 00 E-07 Linear(Acetaldeh ye) R 2 = 0. 7229 1. 50 E-07 1. 00 E-07 5. 00 E-08 0. 00 E+00 130 150 170 190 210 230 Methanol Linear(Methanol) R 2 = 0. 9471
Type 2 Diabetic with 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 Conclusion • 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. 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
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