Milena Aleksić

Continuous, real-time monitoring of volatile organic compounds (VOCs) in surface water is critical for environmental protection, yet conventional laboratory Gas Chromatography–Mass Spectrometry (GC-MS) suffers from analyte loss during sample transport. This study field-validates a portable Membrane Inlet Mass Spectrometry (MIMS) system for direct, on-site monitoring of seven target VOCs (benzene, toluene, xylenes, chlorobenzene, 1,2-dichloroethane, trichloroethylene, and tetrachloroethylene). Laboratory validation established limits of detection between 4 and 8 µg/L, linearity (R² > 0.98), and acceptable precision and accuracy per AOAC guidelines, benchmarked against headspace GC-MS. In-field testing at 36 locations across the Danube–Tisa–Danube (DTD) irrigation canal demonstrated system robustness. Baseline canal samples remained below the detection limits, but real-time MIMS successfully identified localized benzene and toluene contamination near a gasoline station. On-site MIMS detected higher VOC concentrations than delayed laboratory GC-MS, demonstrating its key advantage in preventing sampling volatilization losses. Portable MIMS proves to be a powerful, rapid screening tool for continuous aquatic environmental monitoring.

Continuous, real-time monitoring of volatile organic compounds (VOCs) in surface water is critical for environmental protection, yet conventional laboratory Gas Chro-matography-Mass Spectrometry (GC-MS) suffers from analyte loss during sample transport. This study field-validates a portable Membrane Inlet Mass Spectrometry (MIMS) system for direct, on-site monitoring of seven target VOCs (benzene, toluene, xylenes, chlorobenzene, 1,2-dichloroethane, trichloroethylene, and tetrachloroeth-ylene). Laboratory validation established limits of detection between 4 and 8 µg/L, strong linearity (R2 > 0.98), and acceptable precision and accuracy per AOAC guide-lines, benchmarked against headspace GC-MS. In-field testing at 36 locations across the Danube-Tisa-Danube (DTD) irrigation canal demonstrated system robustness. Baseline canal samples remained below detection limits, but real-time MIMS success-fully identified localized benzene and toluene contamination near a gasoline station. On-site MIMS detected significantly higher volatile concentrations than delayed la-boratory GC-MS, demonstrating its key advantage in preventing sampling volatiliza-tion losses. Portable MIMS proves to be a powerful, rapid screening tool for continuous aquatic environmental monitoring.

This study addresses the need for rapid, in situ detection of volatile organic compounds associated with oil contamination in aquatic environments. Membrane inlet mass spectrometry (MIMS) offers a direct, continuous monitoring approach without the need for chromatographic separation, making it suitable for real-time environmental analysis. In this work, a portable MIMS system was deployed at multiple pilot sites, including a fixed buoy platform, to evaluate its capability for detecting selected hydrocarbon target compounds under field conditions. Measurements were conducted over extended periods, and mass spectral data were continuously recorded and analyzed. Across all monitoring campaigns, no signals corresponding to the target analytes were observed above the established limits of detection. These findings demonstrate the robustness of the applied MIMS configuration for continuous environmental monitoring and confirm its suitability for detecting trace-level pollutants when present. The results also highlight the importance of field validation under realistic conditions, providing a basis for further optimization and broader application of MIMS in environmental surveillance.

This study addresses the need for rapid, in situ detection of volatile organic compounds associated with oil contamination in aquatic environments. Membrane inlet mass spectrometry (MIMS) offers a direct and continuous monitoring approach without the need for chromatographic separation, making it suitable for real-time environmental analysis. In this work, a portable MIMS system was deployed at multiple pilot sites, including a fixed buoy platform, to evaluate its capability for detecting selected hydrocarbon target compounds under field conditions. Measurements were conducted over extended periods, and mass spectral data were continuously recorded and analyzed. Across all monitoring campaigns, no signals corresponding to the target analytes were observed above the established limits of detection. These findings demonstrate the robustness of the applied MIMS configuration for continuous environmental monitoring and confirm its suitability for detecting trace-level pollutants when present. The results also highlight the importance of field validation under realistic conditions, providing a basis for further optimization and broader application of MIMS in environmental surveillance.

In this study, we conducted an extensive computational investigation using various theoretical approaches to elucidate the molecular-level interactions between ten representative volatile organic compounds and functionalized graphene nanosheets.

In the modern world, many people are changing old dietary and lifestyle habits to improve the quality of their living—to treat or just prevent possible diseases. The main goal of this pilot study was to assess the food and lifestyle impact on exhaled breath volatile organic compounds (VOCs) in various population groups. It was done by employing a recently validated portable membrane-inlet mass spectrometer—MIMS. Thus, the obtained results would also represent the additional confirmation for the employment of the new instrument in the breath analysis. The pilot study involved 151 participants across Europe, including people with overweight, obesity, type 2 diabetes mellitus, cardiovascular disease, people with poor-quality diet and professional athletes. Exhaled breath acetone, ethanol, isoprene, and n-pentane levels were determined in samples before the meal, and 120 min after the meal. Obtained basal ppb_v values were mainly in accordance with previously reported, which confirms that MIMS instrument can be used in the breath analysis. Combining the quantified levels along with the information about the participants’ lifestyle habits collected via questionnaire, an assessment of the food and lifestyle impact was obtained. Notable alteration in examined VOC levels upon meal consumption was detected in more than 70% of all participants, with exception for isoprene, which was affected in about half of participants. Lifestyle parameters impact was examined using statistical analysis of variance (ANOVA) on ranks test. Statistically significant differences in basal breath VOC levels were observed among all examined population groups. Also, n-pentane and ethanol levels significantly differed in people of different ages, as well as acetone levels in people with different physical activity habits. These findings are promising for further, more focused research using MIMS technique in breath analysis.

This research work describes the development of a novel bioanalytical method for the assessment of food impact on selected exhaled breath volatile organic compounds (VOCs) using a fast and portable screening VOC prototype sensor based on membrane inlet mass spectrometry (MIMS). Method and sensor prototype functionality was verified by obtaining good response times, linearity in the examined concentration ranges, and sensitivity and repeatability for several breath VOCs—acetone, ethanol, n-pentane, and isoprene. A new VOC sensor prototype was also proven to be sensitive enough for selected breath VOC quantification with limits of detection at low part per billion (ppb) levels—5 ppb for n-pentane, 10 ppb for acetone and ethanol, and 25 ppb for isoprene. Food impact assessment was accomplished by tracking the levels of acetone, ethanol, n-pentane, and isoprene in exhaled breath samples collected from 50 healthy participants before the meal and 60 min and 120 min after the meal. For acetone, isoprene, and n-pentane, a larger impact was noticed 120 min after the meal, while for ethanol, it was after 60 min. Obtained VOC levels were in the expected concentration ranges. Mean values at all time points were ~ 500–900 ppb for acetone and ~ 400–600 ppb for ethanol. Most of the results for n-pentane were below 5 ppb, but the mean value for those which were detected was ~ 30 ppb. Along with samples, data about participants’ lifestyle were collected via a short questionnaire, which were compared against obtained VOC levels in order to reveal some significant correlations between habits of participants and their breath VOC levels. Graphical abstract Portable MS: monitoring of food impact on the levels of selected VOCs from exhaled breath