Quantitative Analysis of Exhaled Breath Collected on Filter Substrates via Low-Temperature Plasma Desorption/Ionization Mass Spectrometry

Abstract

Breath analysis has attracted increasing attention in recent years due to its great potential for disease diagnostics at early stages and for clinical drug monitoring. There are several recent examples of successful development of real-time, in vivo quantitative analysis of exhaled breath metabolites via mass spectrometry. On the other hand, current mass spectrometer accessibility limitations restrict point-of-care applications. Here now, an offline method is developed for quantitative analysis of exhaled breath collected on inexpensive filter substrates for direct desorption and ionization by using low-temperature plasma-mass spectrometry (LTP-MS). In particular, different operating conditions of the ionization source were systematically studied to optimize desorption/ionization by using glycerol, a low volatility compound. Applications with respect to propofol, γ-valprolactone, and nicotine analysis in exhaled breath are demonstrated in this study. The effects of several filter substrate properties, including filter material and pore size, on the analyte signal were characterized. Cellulose filter papers performed best with the present analytes. In addition, filters with smaller pores enabled a more efficient sample collection. Furthermore, sample-collection flow rate was determined to have a very significant effect, with slower flow rates yielding the best results. It was also found that filters loaded with sample can be successfully stored in glass vials with no observable sample loss even after 3 days. Limits of detection under optimized conditions are shown to be competitive or significantly better compared with relevant techniques and with additional benefits of cost-efficiency and sample storage capabilities.

Applications of ambient ionization mass spectrometry in 2022: An annual review

“…Similarly 75 and LTP-MS for the offline analysis of exhaled breath metabolites collected onto filter paper. 76…”

“…Other groups have applied SESI‐MS to identify exhaled breath biomarkers relating to conditions such as sleep apnea 73 and cystic fibrosis, 74 further demonstrating the versatility of the technique to study breath biomarkers of different diseases and disorders. Although less commonly utilized for breath analysis, other AIMS techniques are applied in this area including DART‐MS to monitor changes in breath metabolites throughout the day 75 and LTP‐MS for the offline analysis of exhaled breath metabolites collected onto filter paper 76 …”

“…Although less commonly utilized for breath analysis, other AIMS techniques are applied in this area including DART‐MS to monitor changes in breath metabolites throughout the day 75 and LTP‐MS for the offline analysis of exhaled breath metabolites collected onto filter paper. 76 …”

Low-Temperature Plasma Pretreatment Enhanced Cholesterol Detection in Brain by Desorption Electrospray Ionization-Mass Spectrometry Imaging

“…By means of ROS and RNS principles, it can react and ionize the other compounds . LTP-based mass spectrometry (LTP-MS) has been developed and was recently used in the direct analysis of drugs, − real-time analysis of drugs, and quantitative analysis of exhaled breath . However, there is no MSI report of LTP sample pretreatment as the enhancement of ionization for the analysis of brain lipids by DESI-MSI.…”

Prediction of systemic free and total valproic acid by off-line analysis of exhaled breath in epileptic children and adolescents

“…Alternative non-invasive matrices like breath are an appealing approach for TDM, especially for the pediatric population. Among the anti-seizure medications (ASMs) requiring TDM, valproic acid (VPA) in particular, has been extensively investigated using breath analysis [14][15][16][17].…”