Direct, Selective, and Rapid Measurement of HCN at Sub-ppb Levels Using HiT-CD-IMS: Applications to Cell Culture and...

Area of Science:

• Analytical Chemistry
• Microbiology
• Biomedical Engineering

Background:

• Pseudomonas aeruginosa (PA) infections pose significant health risks.
• Current diagnostic methods can be invasive and time-consuming.
• Hydrogen cyanide (HCN) is a volatile biomarker produced by PA.

Purpose of the Study:

• To develop and validate a sensitive method for detecting HCN emitted by PA.
• To assess the feasibility of using this method for noninvasive infection detection in human breath.

Main Methods:

• Utilized a research-grade ion mobility spectrometer with a high-temperature negative corona discharge ionization source (HiT-CD-IMS).
• Optimized experimental conditions to resolve HCN-specific ions (CN-, CNO-, (CN)2-) and minimize interference (e.g., H2S).
• Applied the method to PA cultures and human breath samples (mouth and nasal exhaled).

Main Results:

• Achieved a high resolving power (63) and a low limit of detection (LOD) of 0.18 ppb for HCN.
• Demonstrated a strong correlation between PA bacterial growth and HCN emission levels.
• Detected significant HCN concentrations in mouth breath (40-300 ppb) and lower levels in nasal breath (<10 ppb).

Conclusions:

• The HiT-CD-IMS method provides sensitive and selective detection of HCN.
• This technique can measure HCN in complex biological matrices like human breath.
• The method shows promise for noninvasive, early detection of Pseudomonas aeruginosa infections.