Comparison of colorimetric, spectroscopic and electrochemical techniques for quantification of hydrogen sulfide

Background: Hydrogen sulfide (H2S), an endogenous gasotransmitter, has potential applications in several conditions. However, its quantification in simulated physiological solutions is a major challenge due to its gaseous nature and other physicochemical properties. Aim: This study was designed to compare four commonly used H2S detection and quantification methods in aqueous solutions. Methods: The four techniques compared were one colorimetric, one chromatographic and two electrochemical methods. Results: Colorimetric and chromatographic methods quantified H2S in millimolar and micromole ranges, respectively. The electrochemical methods quantified H2S in the nanomole and picomole ranges and were less time-consuming. Conclusion: The H2S quantification method should be selected based on the specific requirements of a research project in terms of sensitivity, response time and cost-effectiveness. This work assessed four different methods (colorimetric, chromatographic, voltametric and amperometric) to determine the concentration of hydrogen sulfide (H2S) in aqueous medium. The colorimetric method is relatively simple and inexpensive but requires a greater amount of sample and time for the completion of the process. The chromatographic method is built on the colorimetric method that requires significantly less sample (e.g., 25 mu l vs 1 ml for colorimetric) but exhibits much greater sensitivity (e.g., nM vs mu M) without involving a time-consuming sample preparation step. However, they are relatively more expensive than other methods. Four validated analytical techniques for quantifying and detecting hydrogen sulfide in micromolar to nanomolar range in physiological simulated solutions were compared and contrasted.