Breath Acetone Concentration Research Articles

Breath acetone analysis with miniaturized sample preparation device: In-needle preconcentration and subsequent determination by gas chromatography–mass spectroscopy

A new approach to the determination of human breath acetone with particle-packed sample preparation needle was developed. The extraction needle was packed with a copolymer of methacrylic acid and ethylene glycol dimethacrylate as the extraction medium. For the analysis of breath sample, exhaled breath was collected in a sampling bag, and 50 mL of the breath sample was extracted with the needle-type sample preparation device followed by analysis using gas chromatography–mass spectrometry (GC–MS). After the optimization of several basic extraction conditions for standard acetone samples, breath acetone concentration taken from controlled type-2 diabetic patients was determined. Furthermore, time variations of breath and urine acetone of four healthy individuals under fasting conditions were measured. Urine sample was collected in glass vial, and urine acetone concentration was also determined with the extraction needle by analyzing the corresponding headspace gas. The results demonstrated that the particle-packed extraction needle showed an excellent extraction performance for acetone in both breath and urine headspace samples, and that there is a clear correlation between the concentration of breath acetone and HbA1c level of controlled type-2 diabetic patients. The breath acetone level in controlled diabetic patients was in the range between 0.19 and 0.66 ppmv, where its concentration in medically untreated type-2 patient was 0.92 and 1.20 ppmv. The breath acetone concentration in healthy male was increased to 5.66 ppmv under the 24 h of fasting test, and a high correlation between the breath and urine acetone concentration was also observed. On the basis of the above results, the potential applications of the proposed method to the diagnosis of diabetes and/or ketoacidosis were suggested.

Breath acetone—aspects of normal physiology related to age and gender as determined in a PTR-MS study

The present study was performed to determine the variations of breath acetone concentrations with age, gender and body-mass index (BMI). Previous investigations were based on a relatively small cohort of subjects (see Turner et al 2006 Physiol. Meas. 27 321–37). Since exhaled breath analysis is affected by considerable variation, larger studies are needed to get reliable information about the correlation of concentrations of volatiles in breath when compared with age, gender and BMI. Mixed expiratory exhaled breath was sampled using Tedlar bags. The concentrations of a mass-to-charge ratio (m/z) of 59, attributed to acetone, were then determined using proton transfer reaction-mass spectrometry. Our cohort, consisting of 243 adult volunteers not suffering from diabetes, was divided into two groups: one that fasted overnight prior to sampling (215 volunteers) and the other without a dietary control (28 volunteers). In addition, we considered a group of 44 healthy children (5–11 years old).The fasted subjects' concentrations of acetone ranged from 177 ppb to 2441 ppb, with an overall geometric mean (GM) of 628 ppb; in the group without a dietary control, the subjects' concentrations ranged from 281 ppb to 1246 ppb with an overall GM of 544 ppb. We found no statistically significant shift between the distributions of acetone levels in the breath of males and females in the fasted group (the Wilcoxon-Mann–Whitney test yielded p = 0.0923, the medians being 652 ppb and 587 ppb). Similarly, there did not seem to be a difference between the acetone levels of males and females in the group without a dietary control. Aging was associated with a slight increase of acetone in the fasted females; in males the increase was not statistically significant. Compared with the adults (a merged group), our group of children (5–11 years old) showed lower concentrations of acetone (p < 0.001), with a median of 263 ppb. No correlation was found between the acetone levels and BMI in adults. Our results extend those of Turner et al's (2006 Physiol. Meas. 27 321–37), who analyzed the breath of 30 volunteers (without a dietary control) by selected ion flow tube-mass spectrometry. They reported a positive correlation with age (but without statistical significance in their cohort, with p = 0.82 for males and p = 0.45 for females), and, unlike us, arrived at a p-value of 0.02 for the separation of males and females with respect to acetone concentrations. Our median acetone concentration for children (5–11 years) coincides with the median acetone concentration of young adults (17–19 years) reported by Spanel et al (2007 J. Breath Res. 1 026001).

An acetone breath analyzer using cavity ringdown spectroscopy: an initial test with human subjects under various situations

We have developed a portable breath acetone analyzer using cavity ringdown spectroscopy (CRDS). The instrument was initially tested by measuring the absorbance of breath gases at a single wavelength (266 nm) from 32 human subjects under various conditions. A background subtraction method, implemented to obtain absorbance differences, from which an upper limit of breath acetone concentration was obtained, is described. The upper limits of breath acetone concentration in the four Type 1 diabetes (T1D) subjects, tested after a 14 h overnight fast, range from 0.80 to 3.97 parts per million by volume (ppmv), higher than the mean acetone concentration (0.49 ppmv) in non-diabetic healthy breath reported in the literature. The preliminary results show that the instrument can tell distinctive differences between the breath from individuals who are healthy and those with T1D. On-line monitoring of breath gases in healthy people post-exercise, post-meals and post-alcohol-consumption was also conducted. This exploratory study demonstrates the first CRDS-based acetone breath analyzer and its potential application for point-of-care, non-invasive, diabetic monitoring.

Acetone and Isoprene Concentrations in Exhaled Breath in Healthy Subjects

We measured the concentrations of acetone and isoprene in the exhaled breath from students to evaluate their lifestyles for the annual medical checkup at our university. 451 students were examined for both gases simultaneously by a gas analysis device, Biogas Acetone Analyzer (BAS-2000). The average concentrations of acetone and isoprene in the breath were 0.53±0.45 ppm and 0.065±0.058 ppm, respectively, and the frequency of the abnormal high levels by judging the cut-off values of 1.5 and 0.20 ppm were 3.5% and 2.7% of them, respectively. Acetone concentration in the breath was higher in students having no breakfast in the day of the medical checkup than those having breakfast. Furthermore, acetone concentration was significantly correlated inversely with body fat percentage in students who took the medical checkup in the morning and significantly higher in students with body mass index (BMI) under 25 than obese students with BMI over 25. On the other hand, isoprene concentration was higher in male students than female students, and also higher in smokers than nonsmokers. However, isoprene level was not affected by ingestion of breakfast in the day. Acetone and isoprene concentrations were correlated positively with each other, although the relationship was not affected by having breakfast. The results suggest that the measurement of acetone and isoprene concentrations in the breath is useful for evaluating lifestyles such as lack of breakfast, smoking and obesity in students.

Analysis of human breath with micro extraction techniques and continuous monitoring of carbon dioxide concentration

The detection of volatile organic compounds (VOCs) in human breath can be useful for the clinical routine diagnosis of several diseases in a non-invasive manner. Traditional methods of breath analysis have some major technical problems and limitations. Membrane extraction with a sorbent interface (MESI), however, has many advantages over current methods, including good selectivity and sensitivity, and is well suited for breath analysis. The aim of this project was to develop a simple and reproducible sampling device and method based on the MESI system for breath analysis. The feasibility and validity of the MESI system was tested with real human breath samples. Internal standard calibration methods were used for the quantitative analysis of various breath samples. Calibration curves for some main components (target analytes such as acetone and pentane) were determined in the research. The optimized stripping-side and feeding-side gas velocities were determined. The use of breath CO2 as an internal standard for the analysis of breath VOCs is an effective method to solve the difficulties associated with variations in the target analyte concentrations in a sample, which are attributed to mass losses and different breathing patterns of different subjects. In this study, the concentration of breath acetone was successfully expressed normalized to CO2 as in the alveolar air. Breath acetone of healthy males and females profiled at different times of the day was plotted using the MESI system, and results were consistent with the literature. This technique can be used for monitoring breath acetone concentrations of diabetic patients and for applications with other biomarker monitoring.

CLINICAL STUDY: Quantification of breath carbon disulphide and acetone following a single dose of disulfiram (Antabuse) using selected ion flow tube mass spectrometry (SIFT‐MS)

Selected ion flow tube mass spectrometry (SIFT-MS) has been used to measure simultaneously the concentrations of both carbon disulphide and acetone in exhaled breath following the ingestion of a single dose of disulfiram (Antabuse). Carbon disulphide is a product of the metabolism of disulfiram and is excreted mainly through the lungs. Acetone is a product of normal metabolism and appears in the breath of all individuals. These breath analyses were performed in single exhalations and the results were available in real time. The levels of breath acetone and carbon disulphide were compared with levels obtained from a control subject who had not ingested disulfiram. Breath carbon disulphide was seen to increase from 15 p.p.b. to 618 p.p.b. over a 28-hour period, in the single individual tested, following ingestion of disulfiram, while acetone levels increased from 300 p.p.b. (normal) to over 4000 p.p.b. (greatly elevated). No such increases were seen in the breath of the control subject over the same period. An obvious positive correlation between breath carbon disulphide and acetone concentrations following disulfiram ingestion is seen and discussed.

Impact of inspired substance concentrations on the results of breath analysis in mechanically ventilated patients

A well-defined relationship has to exist between substance concentrations in blood and in breath if blood-borne volatile organic compounds (VOCs) are to be used as breath markers of disease or health. In this study, the impact of inspired substances on this relationship was investigated systematically. VOCs were determined in inspired and expired air and in arterial and mixed venous blood of 46 mechanically ventilated patients by means of SPME, GC/MS. Mean inspired concentrations were 25% of expired concentrations for pentane, 7.5% for acetone, 0.7% for isoprene and 0.4% for isoflurane. Only if inspired concentrations were <5% did substance disappearance rates from blood and exhalation rates correlate well. Exhaled substance concentrations depended on venous and inspired concentrations. Patients with sepsis had higher n-pentane and lower acetone concentrations in mixed venous blood than patients without sepsis (2.27 (0.37–8.70) versus 0.65 (0.33–1.48) nmol L−1 and 69 (22–99) versus 18 (6.7–56) µmol L−1). n-Pentane and acetone concentrations in breath showed no differences between the patient groups, regardless whether or not expired concentrations were corrected for inspired concentrations. In mechanically ventilated patients, concentration profiles of volatile substances in breath may considerably deviate from profiles in blood depending on the relative amount of inspired concentrations. A simple correction for inspired substance concentrations was not possible. Hence, substances having inspired concentrations >5% of expired concentrations should not be used as breath markers in these patients without knowledge of concentrations in blood and breath.

Determination of acetone in human breath by gas chromatography–mass spectrometry and solid-phase microextraction with on-fiber derivatization

Analysis of breath acetone has been used as a diagnostic tool for diabetes. Due to its nature of volatility and activity, it is very difficult to accurately measure the concentration of acetone in human breath by gas chromatography–mass spectrometry (GC–MS). To overcome this problem, we developed a new method using GC–MS and solid-phase microextraction (SPME) with on-fiber derivatization to determine acetone in human breath. Breath gas from controls and diabetic patients was collected in 3-l Tedlar bags. O-2,3,4,5,6-(Pentafluorobenzyl) hydroxylamine hydrochloride (PFBHA) in solution was firstly adsorbed on the SPME fiber of 65 μm polydimethylsiloxane–divinylbenzene (PDMS–DVB), and then the fiber was further headspace exposed in exhaled gas in the Tedlar bag at 40 °C for 4 min. Finally, the formed acetone oxime on the fiber was desorbed and analyzed by GC–MS. Using external standard method, acetone in the human breath was quantitatively analyzed by measurement of its oxime. The method provided a low detection limit of 0.049 ppbv for acetone in breath, relative standard deviation (R.S.D.) value of 3.4%, excellent accuracy. In addition, the method required simple sample preparation and no organic solvent. Acetone in diabetic breath was found to be higher than 1.71 ppmv, while its concentration in normal breath was lower than 0.76 ppmv. The results show that GC–MS and SPME with on-fiber derivatization is a simple, rapid and sensitive and solvent-free method for determination of low concentration acetone in breath and analysis of breath acetone can be used as supplementary tool for diagnosis of diabetes.

On-line, simultaneous quantification of ethanol, some metabolites and water vapour in breath following the ingestion of alcohol

Selected ion flow tube mass spectrometry, SIFT-MS, has been used to measure simultaneously the concentrations in exhaled breath of ethanol, acetaldehyde, ammonia, acetone and, routinely, water vapour, following the ingestion of various amounts of ethanol in 500 ml of water. These breath analyses were obtained from only single exhalations, the results being available immediately in real time. The breath ethanol reaches concentrations that are only approximately consistent with its dilution in blood and body water. For moderate ethanol doses the decay quickly exhibits first-order kinetics (a single exponential decay) whereas for relatively large ethanol doses, the initial decay of ethanol from the breath is slow, indicating saturation kinetics. For smaller doses, and following a meal, the breath ethanol increases only slightly indicating that it is largely metabolized in the stomach. We suggest that the time delay (following ethanol ingestion) before the breath ethanol begins to increase is an indicator of the gastric emptying rate. Then the rate of decay of ethanol from the breath/blood is related to its rate of metabolism subsequent to its dispersal into the body water. The much lower breath acetaldehyde levels correlate well with the ethanol levels indicating that it is mostly formed from the metabolism of the ethanol. The breath ammonia is seen to ‘dip’ following the water/alcohol drink and this is consistent with previous work in which this same phenomenon was observed following the ingestion of comparable volumes of liquid meals. The simultaneous breath acetone concentrations increase somewhat with time as is expected during the fasting state. The water vapour measurements are indicators of the precision and accuracy of the breath analyses, these being sufficient to show the differences between the breath (body) temperatures of the individuals of less than 1 °C. This study demonstrates the potential of SIFT-MS for non-invasive physiological measurement.

Detection of ketosis in dairy cows by analysis of exhaled breath.

In four healthy cows an elevation of ketone bodies was induced by reduction of feed intake. Two cows became clearly ketotic while the other two cows showed only slight increases in ketone body concentrations in serum and milk. Acetone concentrations in exhaled breath were measured by gas chromatography combined with mass spectrometry. These values were correlated with concentrations of serum beta-hydroxybutyric acid (r = 0.81) and milk acetoacetate+acetone (r = 0.70). It is concluded that the ketotic state of dairy cows can be detected by analysis of exhaled breath. This offers a potential non-invasive method of determining the metabolic state of dairy cows.

Breath acetone analyzer: diagnostic tool to monitor dietary fat loss

Acetone, a metabolite of fat catabolism, is produced in excessive amounts in subjects on restricted-calorie weight-loss programs. Breath acetone measurements are useful as a motivational tool during dieting and for monitoring the effectiveness of weight-loss programs. We have developed a simple, easy-to-read method that quantifies the amount of acetone in a defined volume of exhaled breath after trapping the sample in a gas-analyzer column. The concentration of acetone, as measured by the length of a blue color zone in the analyzer column, correlates with results obtained by gas chromatography. Using the breath acetone analyzer to quantify breath acetone concentrations of dieting subjects, we established a correlation between breath acetone concentration and rate of fat loss (slope 52.2 nmol/L per gram per day, intercept 15.3 nmol/L, n = 78, r = 0.81). We also discussed the possibility of using breath acetone in diabetes management.

Breath acetone concentrations in fasting male volunteers: further studies and effect of alcohol administration.

This paper reports the concentration of acetone in end-expired breath of male volunteers as determined by gas chromatography. It also explores the effect of small doses of ethanol, given orally and intravenously, on breath acetone concentrations and their variations with time after intake. When subjects drank a small dose of alcohol (0.25 g/kg) after 12 h fasting, their breath acetone concentration decreased abruptly by 40%. The breath acetone time profile was almost a mirror image of the blood ethanol time course. After 36 h without food, the ethanol-induced drop in breath acetone was 18%. Ethanol given intravenously likewise caused a significant lowering of breath acetone concentration.

Breath-acetone concentrations in fasting healthy men: response of infrared breath-alcohol analyzers.

Six healthy men fasted for 12 and 36 hours, and the resulting concentration of acetone in their breath was determined by gas chromatography. Breath samples were also analyzed by two commercially available breath-alcohol analyzers: Intoxilyzer Model 4011 and Alcotest 7010. Both these devices employ single wavelength infrared absorption spectrometry for detection of ethanol. This IR technique is not specific for ethanol but responds to acetone at the wavelength of 3.4 microns used for light absorption. After the men fasted for 12 hours, their breath-acetone concentrations ranged from 2.3 to 4.0 micrograms/L, and both breath-alcohol analyzers gave zero response (0.000 g/210 L). After 36 hours fasting, breath-acetone concentrations ranged from 33.6 to 157.2 micrograms/L, and the maximum "apparent" ethanol response was 0.005 g/210 L recorded on the Alcotest device. In the test subject with 157.2 micrograms/L acetone in his breath, the intoxilyzer gave a reading of 0.002 g/210 L. The present work shows that elevated breath-acetone concentrations associated with prolonged fasting (36 hours) are not a significant interference problem when infrared breath-alcohol analyzers are used for evidential purposes.

Plasma Acetone Metabolism in the Fasting Human

The metabolism of acetone was studied in lean and obese humans during starvation ketosis. Acetone concentrations in plasma, urine, and breath; and rates of endogenous production, elimination in breath and urine, and in vivo metabolism were determined. There was a direct relationship between plasma acetone turnover (20-77 mumol/m(2) per min) and concentration (0.19-1.68 mM). Breath and urinary excretion of acetone accounted for a 2-30% of the endogenous production rate, and in vivo metabolism accounted for the remainder. Plasma acetone oxidation accounted for congruent with60% of the production rate in 3-d fasted subjects and about 25% of the production rate in 21-d fasted subjects. About 1-2% of the total CO(2) production was derived from plasma acetone oxidation and was not related to the plasma concentration or production rate. Radioactivity from [(14)C]acetone was not detected in plasma free fatty acids, acetoacetate, beta-hydroxybutyrate, or other anionic compounds, but was present in plasma glucose, lipids, and proteins. If glucose synthesis from acetone is possible in humans, this process could account for 11% of the glucose production rate and 59% of the acetone production rate in 21-d fasted subjects. During maximum acetonemia, acetone production from acetoacetate could account for 37% of the anticipated acetoacetate production, which implies that a significant fraction of the latter compound does not undergo immediate terminal oxidation.