Development of an alternative method to quantify H₂S: application in wine fermentation

BACKGROUND A colorimetric method for the quantification of hydrogen sulfide (H₂S) produced in microbial fermentations was developed using lead gelled alginate microparticles packed in glass columns. The formation of a lead sulfide complex, between H₂S and lead ion (Pb 2+ ) immobilized on the microparticles, allowed simple and accurate quantification by colorimetry. RESULTS The microparticle‐loaded columns were calibrated and showed significant analytical sensitivity. The calibration curve of the system showed a correlation coefficient ( r 2 ) of 0.995 and a detection limit of 1.29 ± 0.02 μg L −1 . The application of the columns in laboratory wine fermentations was able to detect variations in H 2 S production from 10.6 to 23.5 μg L −1 by increasing the sugar content in the medium, and from 10.6 to 3.2 μg L −1 with decreasing nitrogen content in the medium. CONCLUSION Validation of the proposed method was carried out by determining H₂S in a vinic fermentation model, the results of which were compared with those obtained using a reference chemical method. The data obtained showed no statistically significant differences between the two methods, confirming the reliability and accuracy of the developed system.